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== General ==
 
== General ==
  
=== What is LinuxBIOS? ===
+
=== What is coreboot? ===
  
LinuxBIOS is a Free Software project aimed at replacing the proprietary BIOS (firmware) you can find in most of today's computers.
+
'''coreboot''' (formerly known as LinuxBIOS) is a Free Software project aimed at replacing the proprietary BIOS (firmware) you can find in most of today's computers.
  
It performs just a little bit of hardware initialization and then executes a so-called [[Payloads|payload]].
+
It performs just a little bit of hardware initialization and then executes what is called a [[Payloads|payload]].
  
Some of the many possible payloads are: a [[Linux]] kernel, [[FILO]], [[GRUB2]], [http://www.openbios.org/ OpenBIOS], [http://www.openbios.org/Open_Firmware Open Firmware], [http://www.openbios.org/SmartFirmware SmartFirmware], [http://www.gnu.org/software/gnufi/ GNUFI] (UEFI), [[Etherboot]], [[ADLO]] (for booting [http://en.wikipedia.org/wiki/Windows_2000 Windows 2000] and [http://openbsd.org/ OpenBSD]), [[Plan 9]], or [[memtest86]].
+
Some of the many possible payloads are: a [[Linux]] kernel, [[FILO]] (a GRUB-like bootloader for booting from disk), [[GRUB2]], [http://www.openbios.org/Open_Firmware Open Firmware], [[Etherboot]]/[[GPXE]], [[SeaBIOS]] (for booting Windows XP, Windows Vista, Windows 7, NetBSD and Linux), and [[Payloads|many others]].
  
Our primary motivation for the project was maintenance of large clusters, but not surprisingly interest and contributions have come from people with varying backgrounds. Today LinuxBIOS can be used in a wide variety of scenarios, ranging from clusters, embedded systems, desktop PCs, servers and more.
+
The initial motivation for the project was maintenance of large clusters, but unsurprisingly, interest and contributions have come from people with varying backgrounds. The latest version of coreboot can be used in a wide variety of scenarios including clusters, embedded systems, desktop PCs, servers, and more.
  
=== Why do we need LinuxBIOS? ===
+
For more information, see [[History]].
  
==== Why do we need LinuxBIOS for cluster maintainance? ====
+
=== Why do we need coreboot? ===
 +
 
 +
==== Why do we need coreboot for cluster maintainance? ====
  
 
Current PCs used as cluster nodes depend on a vendor-supplied BIOS for booting. The BIOS in turn relies on inherently unreliable devices such as floppy disks and hard drives to boot the operating system. In addition, current BIOS software is unable to accommodate non-standard hardware making it difficult to support experimental work. The BIOS is slow and often erroneous and redundant and, most importantly, maintenance is a nightmare. Imagine walking around with a keyboard and monitor to every one of the 128 nodes in a cluster to change one BIOS setting.  
 
Current PCs used as cluster nodes depend on a vendor-supplied BIOS for booting. The BIOS in turn relies on inherently unreliable devices such as floppy disks and hard drives to boot the operating system. In addition, current BIOS software is unable to accommodate non-standard hardware making it difficult to support experimental work. The BIOS is slow and often erroneous and redundant and, most importantly, maintenance is a nightmare. Imagine walking around with a keyboard and monitor to every one of the 128 nodes in a cluster to change one BIOS setting.  
  
LinuxBIOS with Linux as a [[Payloads|payload]] (other payloads are possible!) gunzip's the Linux kernel straight out of NVRAM and essentially requires no moving parts other than the fan. It does a minimal amount of hardware initialization before jumping to the kernel start and lets Linux do the rest. As a result, it is much faster (current record 3 seconds), which has sparked interest in the consumer electronics community as well. Moreover, updates can be performed over the network.  
+
coreboot with Linux as a [[Payloads|payload]] (other payloads are possible!) gunzip's the Linux kernel straight out of NVRAM and essentially requires no moving parts other than the CPU fan. It does a minimal amount of hardware initialization before jumping to the kernel start and lets Linux do the rest. As a result, it is much faster (current record: 3 seconds), which has sparked interest in the consumer electronics community as well. Moreover, updates can be performed over the network.  
  
Using a real operating system to boot another operating system provides much greater flexibility than using a simple netboot program or the BIOS. Because Linux is the boot mechanism, it can boot over standard Ethernet or over other interconnects such as Myrinet, Quadrics, or SCI. It can use SSH connections to load the kernel, or it can use the InterMezzo caching file system or traditional NFS. Cluster nodes can be as simple as they need to be - perhaps as simple as a CPU and memory, no disk, no floppy, and no file system. The nodes will be much less autonomous thus making them easier to maintain.
+
Using a real operating system to boot another operating system provides much greater flexibility than using a simple netboot program or the BIOS. Because Linux is the boot mechanism, it can boot over standard '''Ethernet''' or over other interconnects such as '''Myrinet''', '''Quadrics''', or '''SCI'''. It can use SSH connections to load the kernel, or it can use the '''InterMezzo caching file system''' or traditional '''NFS'''. Cluster nodes can be as simple as they need to be — perhaps as simple as a CPU and memory, no disk, no floppy, and no file system. The nodes will be much less autonomous thus making them easier to maintain.
  
==== Why do we need LinuxBIOS for other purposes? ====
+
==== Why do we need coreboot for other purposes? ====
  
TODO
+
Some aspects of '''DRM''' are not travelling well with the idea of a free computer system. As many computer magazines already pointed out, there may be future restrictions imposed by BIOSes, that a customer is little aware of before purchase and might not harmonize with the idea of freedom and/or security in some cases.
  
=== Who is working on LinuxBIOS? ===
+
=== Who is working on coreboot? ===
  
The LinuxBIOS project was started in the winter of 1999 in the Advanced Computing Laboratory at Los Alamos National Laboratory (LANL) by [[User:Rminnich|Ron Minnich]]. Two undergraduate students, James Hendricks and Dale Webster spent their winter vacation putting together the proof of concept implementation.  
+
The coreboot project was started in the winter of 1999 in the '''Advanced Computing Laboratory at Los Alamos National Laboratory (LANL)''' by [[User:Rminnich|Ron Minnich]]. Two undergraduate students, James Hendricks and Dale Webster spent their winter vacation putting together the proof of concept implementation.  
  
 
Since then, a [[Contributors|long list of people have contributed]] both in discussions and actual code. Please don't be shy and let us know if you are missing from the list. It's not a purposeful omission, just an unfortunate mistake.
 
Since then, a [[Contributors|long list of people have contributed]] both in discussions and actual code. Please don't be shy and let us know if you are missing from the list. It's not a purposeful omission, just an unfortunate mistake.
  
=== Who is funding LinuxBIOS? ===
+
=== Who is funding coreboot? ===
  
The LinuxBIOS project is funded by the Los Alamos Computer Science Institute and the Department of Energy's Office of Science.
+
The coreboot project was initially funded by the Los Alamos Computer Science Institute and the Department of Energy's Office of Science.
  
See also the [[Sponsors|list of LinuxBIOS sponsors]].
+
See also the [[Sponsors|list of coreboot sponsors]].
  
 
== Users ==
 
== Users ==
  
=== Will LinuxBIOS work on my machine? ===
+
=== Will coreboot work on my machine? ===
  
See the [[Supported Motherboards]] page for which mainboards are supported, and also the list of [[Supported Chipsets and Devices]]. See the [[Products]] page for a list of vendors selling products running LinuxBIOS.
+
See the [[Supported Motherboards]] page for which mainboards are supported, and also the list of [[Supported Chipsets and Devices]]. See the [[Products]] page for a list of vendors selling products running coreboot. Finally, you could look at the coreboot source tree, in src/mainboard.
  
If the above sources don't help, please send the following to the [[Mailinglist|mailing list]]:
+
If your board is not already supported, it will likely take you years of work to port coreboot to operate correctly on it unless you have experience with firmware level C development and good knowledge of the underlying (x86 or ARM) architecture.
  
* Step 1: A very brief description of your system: CPU, northbridge, southbridge, mainboard and optionally other important details.
+
If you do not see your board in the above sources, please send the following to the [[Mailinglist|mailing list]]:
* Step 2: Linux lspci output for your system, generated by booting Linux via the original BIOS and runnning lspci.
+
 
* Step 3: Super I/O chip on the mainboard (report the model numbers on the actual chip, for example "Winbond W83627HF").
+
* Step 1: A very brief description of your system: board vendor, board name, CPU, northbridge, southbridge, and optionally other important details.
* Step 4: Type of BIOS device (see the question "How do I identify the BIOS chip on my mainboard?" below).
+
* Step 2: Linux "'''lspci -tvnn'''" output for your system, generated by booting Linux via the original BIOS and runnning lspci.
 +
* Step 3: Super I/O chip on the mainboard (report the model numbers on the actual chip, for example "Winbond W83627HF" and/or run "'''[[superiotool]] -dV'''").
 +
* Step 4: Type of BIOS device (see the question "How do I identify the BIOS chip on my mainboard?" below). Please send us the output of "'''[http://flashrom.org flashrom] -p internal -V'''"
 
* Step 5: URL to the mainboard specifications page (optional).
 
* Step 5: URL to the mainboard specifications page (optional).
 
* Step 6: Any other relevant information you can provide.
 
* Step 6: Any other relevant information you can provide.
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If you can't do step 1 above, please describe (as best you can) the specific CPU chip and the chipset used on the mainboard.
 
If you can't do step 1 above, please describe (as best you can) the specific CPU chip and the chipset used on the mainboard.
  
Usually in less than a day, someone will respond on the LinuxBIOS mailing list saying your mainboard is supported in the main LinuxBIOS source tree, it is currently in development, it is not yet supported or the manufacturer will not release information needed to provide LinuxBIOS support. In the latter case, please let the manufacturer know that you want LinuxBIOS support and his failure to release chipset information is making that very difficult.
+
Usually in less than a day, someone will respond on the coreboot mailing list, most often with bad news. However it is possible that your mainboard is supported in the main coreboot source tree, or that support is currently in development, so it won't hurt to ask. It's also possible (and unfortunately, likely) that the manufacturer will not release information needed to provide coreboot support. In the latter case, please let the manufacturer know that you want coreboot support and his failure to release chipset information is making that very difficult.
  
=== What commercial products use LinuxBIOS? ===
+
=== What commercial products use coreboot? ===
  
 
See the [[products]] page.
 
See the [[products]] page.
  
=== Which different operating systems will LinuxBIOS boot? ===
+
=== Which different operating systems will coreboot boot? ===
  
* Linux (of course)
+
coreboot should support almost any modern operating system. To support operating systems that use [http://en.wikipedia.org/wiki/BIOS_interrupt_call BIOS calls], [[SeaBIOS]] is mandantory, as coreboot doesn't provide these by itself:
  
 +
* Linux
 
* Plan 9
 
* Plan 9
 +
* FreeDOS (via [[SeaBIOS]])
 +
* Windows 2000, XP, Vista, 7(RC) (via [[SeaBIOS]], the boot loader requires BIOS)
 +
* NetBSD, MirBSD (via [[SeaBIOS]] as at least the boot loader requires BIOS)
  
* Windows 2000 (via [[ADLO]])
+
coreboot does '''not''' natively support:
  
We have looked at some of the BSD OSes but (e.g.) FreeBSD makes BIOS calls, and we don't support
+
* We have tested some of the BSD OSes and have seen, that FreeBSD for example makes BIOS calls, which is not supported by coreboot. Possibly with help of [[SeaBIOS]], it may be possible to boot FreeBSD like it is now, but the right thing to do, is to remove FreeBSD's dependence on BIOS calls.
BIOS calls. Possibly ADLO could be used to support FreeBSD, but the right thing to do is remove
+
* Windows versions older than Windows 2000, as they make BIOS calls ([[SeaBIOS]] might help)
FreeBSD's dependence on BIOS calls.
+
* [http://www.menuetos.net/ MenuetOS], as it makes BIOS calls ([[SeaBIOS]] might help)
 +
 
 +
Please feel free to test booting any of the above using [[SeaBIOS]] and report to the coreboot mailing list.
  
 
=== What chipsets and Super I/O devices are supported? ===
 
=== What chipsets and Super I/O devices are supported? ===
Line 79: Line 89:
  
 
See [[Mailinglist]].
 
See [[Mailinglist]].
 +
 +
=== Is there a coreboot IRC channel? ===
 +
 +
Yes, see [[IRC]].
  
 
=== Where do I get the code? ===
 
=== Where do I get the code? ===
  
See the [[Download LinuxBIOS|download page]].
+
See the [[Download coreboot|download page]].
  
=== How do I build LinuxBIOS? ===
+
=== How do I build coreboot? ===
  
See the [[documentation]].
+
See the [[Build HOWTO]].
  
=== How can I help with LinuxBIOS? ===
+
=== How can I help with coreboot? ===
  
 
There are many ways how you can help us:
 
There are many ways how you can help us:
* Promote LinuxBIOS, tell all your friends about it, blog about it etc.
+
 
* Test LinuxBIOS, [http://tracker.linuxbios.org/trac/LinuxBIOS/newticket report] any bugs you find, or let us know about any suggestions for improvements you have.
+
* You can ask for a Wiki account. Send a private message with your preferred username and email to ''pgeorgi'' or ''stefanct'' in the #coreboot [[IRC]] channel at freenode.net.
 +
* Promote coreboot, tell all your friends about it, blog about it etc.
 +
* Test coreboot, report any bugs you find to our [[Mailinglist|mailinglist]] or to our [[Development_Guidelines#Bug-Tracker|bug tracker]], or let us know about any suggestions for improvements you have.
 
* Help us to make the list of [[Supported Motherboards]] and the list of [[Supported Chipsets and Devices]] bigger by contributing code. Please also read the [[Development Guidelines]] in that case.
 
* Help us to make the list of [[Supported Motherboards]] and the list of [[Supported Chipsets and Devices]] bigger by contributing code. Please also read the [[Development Guidelines]] in that case.
* Have a look at the [http://tracker.linuxbios.org/trac/LinuxBIOS/report/1 list of open issues/bugs] and try to reproduce them or (preferrably) fix them.
+
* If you have a mainboard with USB2 (EHCI-controller) you can look if it supports the [[EHCI Debug Port]] and mail the information to us, if it is not already there.
* Contact [[User:Rminnich|Ron Minnich]] or [[User:Stepan|Stefan Reinauer]] for bigger projects related to LinuxBIOS.
+
** If you are familiar with microcontroller development, you might be able to build a debugging tool for the [[EHCI Debug Port]]. If you are successful, we like to hear about it.
 +
* Test, if QNX or Solaris are able to boot on a mainboard with coreboot.
 +
* Have a look at the list of open issues/bugs in our [[Mailinglist|mailinglist]] (as current [[Development_Guidelines#Bug-Tracker|bug tracker]] is dead) and try to reproduce them or (preferrably) fix them.
 +
* Contact [[User:Rminnich|Ron Minnich]] or [[User:Stepan|Stefan Reinauer]] for bigger projects related to coreboot.
 
* Contact us on the [[Mailinglist|mailing list]] if you have any further questions or suggestions.
 
* Contact us on the [[Mailinglist|mailing list]] if you have any further questions or suggestions.
  
== Developers ==
+
=== What do the abbreviations in this wiki stand for? ===
  
=== What kind of hardware tools do I need? ===
+
See [[Glossary]].
  
A motherboard (or mainboard as LinuxBIOS calls it) that has a supported chipset on it. Ok... well not exactly. As long as you have the documentation for the chipset/mainboard and it's free of any NDA issues you can use an unsupported chipset/mainboard, but you have a twisty road ahead of you.
+
=== Can I play the latest PC games on a coreboot platform? ===
 
And of course you need a Linux development machine. The LinuxBIOS build environment is not supported on Windows. It may be possible to do it under cygwin but nobody has tried.
 
 
It's also handy to have one/some/all of the following:
 
 
==== EPROM/Flash programmer that can program the flash on your motherboard ====
 
  
* [http://www.mcumall.com/ Willem Universal EPROM Programmer] -- DOS/Windows only (work has started on Linux drivers) ~$50
+
Of course.
* [http://www.conitec.net/english/software.htm GALEP-4] -- Has beta linux drivers ~$300
 
* [http://www.loet.de/flasher_en.html IDE adapter for PLCC32 & DIP32 sockets] -- Has Linux 2.4 & 2.6 drivers ~$48EUR (kit $33EUR)
 
  
==== Bios Savior ====
+
The current performance coreboot compatible x86-64 motherboard is the [[Board:asus/kgpe-d16|KGPE-D16]] which has dual PCI-e x16 2.0 slots, 192GB max RAM and can support fast CPU's such as the G34 16 core Opteron 6386SE, 6287SE and 6284SE - with one of those the bottleneck will be always be GPU related if you are playing a highly multi-threaded game.
  
[[Image:Bios savior.jpg|thumb|right|Photo of an installed BIOS saviour.]]
+
If you aren't using the computer for something very important you can save a lot of money and have an affordable libre firmware gaming platform by getting a used CPU. You can even use IOMMU-GFX to have multiple separate VM's and thus have more than one player on the same machine (needs one gfx card per VM)
  
A tool that plugs into and replaces the original mainboard Flash device. The BIOS Savior has its own Flash device and a socket for the original mainboard Flash device. The Bios Savior features a switch to allow the developer to choose between which Flash device is accessed by the mainboard during read and write cycles.
+
If you do not want to have to buy an SSI-EEB compatable case there is also the [[Board:asus/kcma-d8|KCMA-D8]] which is the KGPE-D16's regular ATX little brother, although the CPU's max out at 8 cores per and there aren't as many PCI-e slots (no dual x16 so no crossfire).
  
* http://www.ioss.com.tw/web/English/RD1BIOSSavior.html
+
NOTE: game needs to be highly multithreaded due to poor c32/g34 opteron single threaded performance, having half core turbo functional helps with this. Thus brand new and old games work great but games from 3-6 years ago may work poorly.
* http://www.cwlinux.com/eng/products/products_lbmb.php
 
  
A similar function is achieved by the "'''top hat flash'''" which comes at no extra cost with many Elitegroup mainboards like KN3 with MCP55 southbridge. After bootup, it can manually be lifted off the original BIOS chip socket, so the original BIOS can be reflashed after a failure.
+
Opteron C32/G34 CPU's to buy for gaming:
  
==== POST card ====
+
G34 16 core:
 +
6386SE
 +
6287SE
 +
6284SE
  
See the [http://www.linuxbios.org/index.php/FAQ#What_is_this_POST_card_thing.3F What is a POST Card?] question in this FAQ.
+
G34 8 Core:
 +
6328 (approx FX-8310)
  
* http://siliconkit.dnsalias.com/cart/index.tpcip.html
+
C32 8 Core
* http://www.elstonsystems.com/prod/pc_analyzer.html
+
4386
* http://shopv2.elstonsystems.com/product_info.php/products_id/57
 
* http://www.uxd.com/trio.html
 
* http://www.soyousa.com/products/proddesc.php?id=261
 
  
==== Compact Flash IDE adaptor ====
+
Note: On multi CPU or 16 core setups you will have poor performance and stuttering if your OS does not properly allocate NUMA memory.
  
* http://siliconkit.dnsalias.com/cart/index.tcfdp.html
+
== Developers ==
* http://www.cwlinux.com/eng/products/products_ide2cf.php
 
* http://www.mini-box.com/s.nl/sc.8/category.14/.f
 
* http://www.acscontrol.com/Index_ACS.asp?Page=/Pages/Products/CompactFlash/IDE_To_CF_Adapter.htm
 
* http://www.pcengines.ch/cflash.htm
 
* http://www.psism.com/adcf.htm
 
* http://www.hsc-us.com/industrial/adapter/ATP.html (2xCF, one with hotswap!)
 
* http://www.mesanet.com/ (Choose DISK EMULATORS then CFADPTHD in the menu. 2xCF)
 
  
==== Oscilloscope ====
+
=== Where can I buy BIOS chips (empty or pre-flashed)? ===
  
For hardware debugging purposes.
+
When developing or simply trying out coreboot you always need a means to revert to your old BIOS in case something goes wrong. One way to do this is to get an extra BIOS chip (PLCC32, DIP32, DIP8, or other) and copy your original BIOS image onto that chip (using [http://flashrom.org flashrom], for example). If you have a socketed BIOS (not soldered onto the mainboard), you can hot-swap the chips while your computer is running (Do not hot swap with your hands - You must use an insulated chip removal tool to avoid a short-circuit)
  
==== In Circuit Emulator hardware debugger ====
+
You have several options to get spare BIOS chips:
 +
* Most local or online electronics dealers carry some, for example:
 +
** Germany:
 +
*** http://www.bios-chip.com / http://www.bios-express.de (same company)
 +
*** http://www.bios-fix.de
 +
*** http://www.bios-chips.com
 +
*** http://www.conrad.de
 +
*** http://www.endrich.com/de/site.php/47385 (it's unknown whether they ship small quantities)
 +
*** http://www.chip-service.de
 +
*** http://www.neumueller.com/
 +
** UK:
 +
*** http://bios-repair.co.uk/
 +
** US:
 +
*** http://avnet.com
 +
*** http://mouser.com
 +
*** http://semiconductorstore.com/
 +
* You can search eBay for BIOS chips (either empty ones or pre-flashed ones).
 +
* You can rip out chips from old/broken mainboards and re-use them (you can check flea markets, eBay, etc. for cheap and/or broken mainboards).
  
* ...
+
=== What kind of hardware tools do I need? ===
 
 
==== LinuxBIOS SDK ====
 
 
 
* http://www.cwlinux.com/eng/products/products_sdk.php
 
 
 
==== In Circuit chip programmer ====
 
 
 
Should allow you to program your BIOS even if it is soldered to the motherboard.
 
  
* http://www.xeltek.com/pages.php?pageid=8
+
See the [[Developer Manual#Required_hardware_and_software_tools_for_developers|hardware tools section]] of the [[Developer Manual|developer's manual]].
  
==== EPROM emulators ====
+
=== How do I use a null-modem cable to get coreboot debugging output over a serial port? ===
 
 
These hardware devices pretend to be an EPROM chip.
 
 
 
* http://www.tech-tools.com/romtools.htm
 
* http://xtronics.com/memory/pktROM.htm
 
* http://www.tribalmicro.com/multirom/
 
* http://www.linuxselfhelp.com/HOWTO/Diskless-HOWTO-10.html (a larger list -- outdated)
 
 
 
 
 
==== USB debug devices ====
 
 
 
an alternative to a serial console may be a USB debug device. They are not so common yet. Their advantage is higher speed than a serial console. One might hook an FPGA to it for profiling purposes or some automated checks. Accessing a USB debug device from within BIOS is not different than other USB devices, and is part of the USB standard.
 
  
 +
* First, you'll want to set up a terminal program, e.g. '''minicom''' correctly.
 +
$ minicom -s
 +
  -> Serial port setup
 +
  -> Press A and enter your COM device (ttyS0 or ttyS1 or ttyUSB0, depending on your COM port)
 +
  -> Press E and choose "115200 8N1" (default)
 +
  -> Disable Hardware and Software Flow Control (via F and G)
 +
  -> Press enter to leave the menu
 +
  -> Save setup as..
 +
  ->  Enter "lb"
 +
  -> Exit from minicom
 +
* From now on, you can start minicom with the obove settings simply by typing:
 +
$ minicom -o lb
  
 
=== What documentation do I need? ===
 
=== What documentation do I need? ===
Line 183: Line 196:
 
As much documentation as you can possibly get your hands on.  At minimum, you will need the docs for the chipset.
 
As much documentation as you can possibly get your hands on.  At minimum, you will need the docs for the chipset.
 
 
There have been reports of people getting LinuxBIOS working by booting with the OEM BIOS. Then, they would read the static contents of the PCI config registers after boot. LinuxBIOS is then built to match the static contents read from the PCI config registers.  
+
There have been reports of people getting coreboot working by booting with the OEM BIOS. Then, they would read the static contents of the PCI config registers after boot. coreboot is then built to match the static contents read from the PCI config registers.  
  
 
The problem with this approach is that chipsets generally require dynamic vs static configuration values during their initialization. The configuration register contents will change from one stage of initialization to the next. Since the contents of the registers read is only the final state of the configuration registers, the chipset won't be properly initialized if these are the only configuration values used.
 
The problem with this approach is that chipsets generally require dynamic vs static configuration values during their initialization. The configuration register contents will change from one stage of initialization to the next. Since the contents of the registers read is only the final state of the configuration registers, the chipset won't be properly initialized if these are the only configuration values used.
Line 191: Line 204:
 
=== What if my chipset docs are covered by an NDA? ===
 
=== What if my chipset docs are covered by an NDA? ===
  
If the documentation for your chipset covered by and NDA with no source release agreement you won't be able to release your code back to to the LinuxBIOS project in general or you will violate the GPL.
+
If the documentation for your chipset covered by a NDA with no source release agreement, you won't be able to release your code back to the coreboot project in general, or you will violate the GPL.
Many vendors accept releasing the source code produced after reading such specs while they don't allow the specs themselves to be revealed. Also, you can offer them to review the code before releasing it.
+
Many vendors accept releasing the source code, produced after reading such specs, while they don't allow the specs themselves to be revealed. Also, you can offer them the opportunity to review your code, before releasing it to the public.
  
 
=== Why is the code so complicated and what can I do to make it easier? ===
 
=== Why is the code so complicated and what can I do to make it easier? ===
  
 
The reason is the complexity of the problem. We support a lot of hardware, and a given chip on a given board will most likely not be configured quite the same as the same chip on some other board. To help make code navigation easier, pick a target and build that target. Then, in the build directory, type make tags or make etags to get your favorite tags file.  
 
The reason is the complexity of the problem. We support a lot of hardware, and a given chip on a given board will most likely not be configured quite the same as the same chip on some other board. To help make code navigation easier, pick a target and build that target. Then, in the build directory, type make tags or make etags to get your favorite tags file.  
 
=== What is this POST card thing? ===
 
 
A POST card will save your life. The term POST means Power On Self Test and comes from the original IBM specifications for the BIOS. Port 80 is a pre-defined port to which programs can output a byte. The POST card displays the byte in hex on its 2 digit display. We use a lot of POST codes in LinuxBIOS, so if you can tell us the POST code you see, we will have some idea of what happened.
 
 
If your LinuxBIOS machine is working properly, you will see it count up from 0xd0 to 0xd9 (while it is gunzipping the kernel) and then display 0x98 (Linux idle loop).
 
 
PCI POST cards can be found in various places.
 
[http://www.linuxbios.org/index.php/FAQ#Developer POST Cards]
 
  
 
=== How do I contribute my changes? ===
 
=== How do I contribute my changes? ===
  
Please carefully read the [http://linuxbios.org/Development_Guidelines Development Guidelines] for more information.
+
Please carefully read the [http://coreboot.org/Development_Guidelines Development Guidelines] for more information.
  
 
=== How do I identify the BIOS chip on my mainboard? ===
 
=== How do I identify the BIOS chip on my mainboard? ===
  
Modern mainboards store the BIOS in a reprogrammable flash ROM chip. There are hundreds of different flash ROMs, with variables such as memory size, speed, communication bus (LPC vs. ISA/PCI) and packaging to name just a few. The three most common packages are called DIP, PLCC and TSOP. The BIOS copyright holders often place a fancy sticker on the BIOS chip showing a name or logotype, BIOS version, serial number and copyright notice.
+
Please see [http://flashrom.org/Technology].
  
==== DIP: Dual In-line Package ====
+
=== How do I (re-)flash the BIOS? ===
  
[[Image:ROM BIOS.jpg|thumb|right|A DIP BIOS chip.]]
+
==== Out of mainboard BIOS (re)flash ====
 
 
A rectangular black plastic block with lots of pins along the two longer sides of the package. DIP ROMs can be socketed which means they are detachable from the mainboard using physical force. Since they haven't been moved in and out of the socket very much (yet, hehe) they can appear to be quite difficult to release from the socket. One way to remove a DIP from a socket is by prying a thin screwdriver in between the plastic package and the socket, along the shorter sides where there are no pins, and then gently bending the screwdriver to push the DIP upwards, away from the mainboard. Alternate between the two sides to avoid bending the pins, and don't touch any of the pins with the screwdriver, see FAQ about ESD, electro-static discharge. If the DIP is soldered directly to the mainboard, it has to be desoldered in order to be reprogrammed outside the mainboard. If you do this, it's a good idea to solder a socket to the mainboard instead, to ease any future experiments.
 
 
 
==== PLCC: Plastic Leaded Chip Carrier ====
 
 
 
[[Image:2 W39V040BPZ.png|thumb|right|A socketed PLCC BIOS chip.]]
 
 
 
Black plastic block again, but this one is much more square. PLCC is becoming the standard for mainboards because of it's smaller physical size. PLCC can also be socketed or soldered directly to the mainboard. Socketed PLCC chips can be removed using a special PLCC removal tool, or using a piece of nylon line tied in a loop around the chip and pulled swiftly straight up, or bending/prying using small screwdrivers if one is careful. PLCC sockets are often fragile so the screwdriver approach is not recommended. While the nylon line method sounds onorthodox it works well. Desoldering PLCC can be painful without specialized desoldering equipment particularly because PLCC chips have leads on all four sides of the package.
 
 
 
==== TSOP: Thin Small-Outline Package ====
 
  
[http://www.isipkg.com/images/adp_tsop_dip.jpg TSOP chip on a TSOP->DIP adapter]
+
If the BIOS chip is socketed, it can be removed and flashed in a rom/flash burner and quickly re-installed.
  
TSOPs are often used in embedded systems where size is important and there is no need for replacement in the field. It is possible to (de)solder TSOPs by hand, but it comes close to wizardry.
+
You have the option of using the [http://www.flashrom.org/Supported_hardware external programmers supported by flashrom] or some other external programmer which comes with its own software. Depending on the flash chip type, various options exist. For older parallel flash chips, some of these burners cost $700 and more plus they complete a flash in 30 seconds (like the [http://www.conitec.net/english/galep5.php Conitec Galep V]), but if you are willing to wait 5 minutes for a flash and manually set DIP switches, the Enhanced Willem Universal Programmer will do the job for only $40-60 USD.  There are several models of the Willem Programmer, each supporting many chips, but not all, so be sure to get one that supports your BIOS chip. You could also use the [http://www.flashrom.org/Paraflasher Paraflasher] which is a really low-cost programmer with parts sold for $20 or less. The [http://flashrom.org flashrom] wiki has a list of hardware you can use for programming.
  
=== How do I (re-)flash the BIOS? ===
+
If your chip is PLCC, you will also need the push pin trick or a PLCC chip extractor/puller or just thread nylon string under the PLCC chip from corner to corner and yank up it straight up. Read more about chip extraction in the [[Developer_Manual/Tools#Chip_removal_tools|developer manual]].
 
 
==== Out of mainboard BIOS (re)flash ====
 
 
 
If the BIOS chip is socketed, it can be removed and flashed in a rom/flash burner and quickly re-installed.  Some of these burners cost $1000 and more plus they complete a flash in 1-2 minutes, but if you are willing to wait 5 minutes for a flash and manually set DIP switches, The Enhanced Willem Universal Programmer will do the job for only $40-60 USD.  There are several models of the Willem Programmer, each supporting many chips, but not all, so be sure to get one that supports your BIOS chip.  If your chip is PLCC, you will also need a PLCC chip extractor/puller or just thread nylon string under the PLCC chip from corner to corner and yank up it straight up.
 
  
 
==== Inside mainboard BIOS (re)flash ====
 
==== Inside mainboard BIOS (re)flash ====
  
Download the appropriate flash update utility. Build the romimage as explained above and use the flash update utility to update the BIOS. Be warned that not all update utilities allow you to load your own BIOS image. For example, Intel decided to disallow it for the MS440GX mainboard (probably after hearing about us!) Here are some mainboard specific directions:
+
Download the appropriate flash update utility. Build the coreboot image as explained above and use the flash update utility to update the BIOS. Be warned that not all update utilities allow you to load your own BIOS image. NOTE: Many vendor specific flash utilities refuse to write "foreign" BIOS images, such as coreboot.
  
===== General =====
+
Therefore we suggest that you use the universal flash utility called [http://www.flashrom.org/ flashrom] which was developed and improved by many coreboot developers, and it works under Linux/*BSD/MacOSX/Solaris/DOS.
LinuxBIOS v2 contains a flash utility called flashrom in the util/flashrom directory. (Old versions had "util/flash_and_burn/flash_rom" instead).
 
  
 
Example:
 
Example:
 
  bash$ sudo ./flashrom -V
 
  bash$ sudo ./flashrom -V
  Calibrating delay loop... Setting up microsecond timing loop
+
  flashrom v0.9.2-r1000 on Linux 2.6.34-rc7-git5 (x86_64), built with libpci 3.1.7, GCC 4.4.3
216M loops per second
+
  flashrom is free software, get the source code at http://www.flashrom.org
ok
+
   
Found canidate at: 00000530-00000bc4
+
  No coreboot table found.
Found LinuxBIOS table at: 00000530
+
  Found chipset "Intel ICH9", enabling flash write... OK.
lb_table found at address 0xb7e1c530
+
This chipset supports the following protocols: FWH,SPI.
LinuxBIOS header(24) checksum: 404a table(1684) checksum: 2766 entries: 14
+
Calibrating delay loop... 663M loops per second, 100 myus = 199 us. OK.
vendor id: via part id: epia-m
+
Found chip "Winbond W25x80" (1024 KB, SPI) at physical address 0xfff00000.
Enabling flash write on VT8235...OK
+
No operations were specified.
  Trying Am29F040B, 512 KB
 
probe_29f040b: id1 0x20, id2 0xe2
 
Trying ST29F040B, 512 KB
 
  probe_29f040b: id1 0x20, id2 0xe2
 
  ST29F040B found at physical address: 0xfff80000
 
  Flash part is ST29F040B
 
OK, only ENABLING flash write, but NOT FLASHING.
 
 
 
 
 
If neither utility supports your chip, then you could either use the DOS [http://www.uniflash.org/ uniflash] utility, or use its source code, which is also available for download from the uniflash site (in Turbo Pascal 7) as a reference for adding support for your flash chip to "flash_rom". Uniflash supports a lot of different flash chips, and chip interfaces. It has untested support for PCI expansion card flash BIOS, such as on RTL8139 Ethernet card (32pin DIL), which allows flashing on the NIC if manufacturer provides the circuitry.
 
 
 
===== SiS 630/950 M/Bs =====
 
Ollie Lho provided us with flash utilities for these boards under freebios/util/sis.  
 
flash_on turns on the flash write enable. This needs to be run before loading the DoC drivers.  
 
flash_rom allows you to use your SiS 630/950 M/Bs as a flash programmer. It currently supports JEDEC flash parts, AMD am29f040b models, MXIC MX29F002 models, and SST28SF040C models.  
 
  
===== Intel L440GX =====
+
Alternatively you could either use the DOS [http://www.rainbow-software.org/uniflash/ uniflash] utility, or use its source code, which is also available for download from the uniflash site (in Turbo Pascal 7) as a reference for adding support for your flash chip to [http://flashrom.org flashrom].  Uniflash supports a lot of different flash chips, and chip interfaces, but so far SPI support is only present in flashrom. You can use flashrom and uniflash for PCI expansion card flashing, such as on RTL8139 Ethernet card (32pin DIL), which allows flashing of your BIOS chip on the NIC if manufacturer provides the circuitry. Please note that flashrom and uniflash support different cards and you should check which utility supports the programmer hardware you own.
Get the System Update Package directly from Intel. mcopy the ten files created from running make phlash onto the Intel flash burner disk and use the update utility to burn the BIOS. To restore the original BIOS, set the recovery boot jumper on the motherboard, put the floppy in, and it will load and reflash the original BIOS.  
 
How do I actually burn a flash ROM?
 
  
Buy your favorite flash burner (we use a Needham Electronics EMP 30). Use make floppy to create the romimage and copy it to a floppy. Then use the provided software to burn the flash.
+
Another tool which runs in linux is [http://sourceforge.net/projects/ctflasher/ ctflasher], but it is not maintained anymore and might not work with current Linux kernels.
  
  
Line 294: Line 266:
 
* Step 4 - Program the original BIOS image (or other known good BIOS image) into the RD1's integrated flash device. Do this as many times as needed until the device is properly programmed and the system boots corectly from the RD1's integrated flash device. Be sure to check the settings on the RD1 so that the proper flash device is now being programmed. If the RD1 is not set correctly the working BIOS image will be erased and the system will not boot!
 
* Step 4 - Program the original BIOS image (or other known good BIOS image) into the RD1's integrated flash device. Do this as many times as needed until the device is properly programmed and the system boots corectly from the RD1's integrated flash device. Be sure to check the settings on the RD1 so that the proper flash device is now being programmed. If the RD1 is not set correctly the working BIOS image will be erased and the system will not boot!
  
* Step 5 - Program the test BIOS image (usually LinuxBIOS images are among this group) into the original flash device from the mainboard. The original BIOS device usually programs OK on the first attempt. Be sure to check the settings again on the RD1 so that the proper flash device is being programmed!
+
* Step 5 - Program the test BIOS image (usually coreboot images are among this group) into the original flash device from the mainboard. The original BIOS device usually programs OK on the first attempt. Be sure to check the settings again on the RD1 so that the proper flash device is being programmed!
  
  
Line 309: Line 281:
 
* Aggressive and/or inappropriate use of metal objects such as screwdrivers (2 casualties)  
 
* Aggressive and/or inappropriate use of metal objects such as screwdrivers (2 casualties)  
 
* Miscellaneous miswirings and mishandlings (3+ casualties)
 
* Miscellaneous miswirings and mishandlings (3+ casualties)
 +
 +
remember: make sure your important data is on a disconnected drive while you experiment.
  
 
=== A note on electrostatic discharge (ESD) and ESD protection (thanks to Bari Ari) ===
 
=== A note on electrostatic discharge (ESD) and ESD protection (thanks to Bari Ari) ===
Line 324: Line 298:
 
* Table or workspace that is clean, clear of dust, and away from electrical machinery or other equipment that generates electrical currents.  
 
* Table or workspace that is clean, clear of dust, and away from electrical machinery or other equipment that generates electrical currents.  
  
The idea is to ensure that all components you are going to interact with have the same charge. By connecting everything to the computer case, you ensure that the components of the case, the chair, and your body all have the same charge. If every object has the same charge, the electrons will not jump from one object to another minimizing the risk of ESD damage.  
+
The idea is to ensure that all components you are going to interact with have the same charge. By connecting everything to the computer case, you ensure that the components of the case, the chair, and your body all have the same charge. If every object has the same charge, the electrons will not jump from one object to another minimizing the risk of ESD damage.
  
=== How do I turn off embedded sis630 devices? ===
+
=== What is a PIRQ table? ===
  
From aip@cwlinux.com Mon Mar 25 08:54:07 2002
+
There's a good description of the BIOS implementation of the PIRQ in the ''red PCI book'', and here's a [http://www.microsoft.com/whdc/archive/pciirq.mspx description of the $PIR data structure].
Date: Mon, 25 Mar 2002 22:07:54 +0800
 
From: Andrew Ip
 
To: Kei Furuuchi
 
Cc: linuxbios@lanl.gov
 
Subject: Re: How to turn off unused pci device.
 
Hi,
 
> I have pcchips m758lmr which has audio chip besides sis630.
 
> those functions in sis630 are not used in the motherboard.
 
> But, the functions keep coming up. How do I turn off those?
 
The following is from Nikolai Valdych previous message. Hope this help.
 
-Andrew
 
--
 
Andrew Ip
 
Email: aip@cwlinux.com
 
Actualy, it was pretty simple 0x7c00 - All devices enabled, You play with first 4 bits only. Cos there are 4 devices, so you have any combination of 4 bits.
 
Set bit to 1 to turn off the device, bit 0 to enable it.
 
This is the device list:
 
Multimedia Audio controler
 
Modem controler
 
Ethernet sis930 controler
 
USB controler.
 
For example, to turn off Ethernet + USB it would be:
 
0x7c0c -> 1100 in binary (first 4 bits)
 
To turn off Multimedia audio :
 
0x7c01 -> 0001
 
in binary and so on... maybe there are more detail, but this is enogh for me, Ollie, again thanks!
 
nikolai
 
p.s. though my modem is not yet working..... damn driver......  
 
  
=== What is a PIRQ table? ===
+
coreboot saves the $PIR data structure between 0xf0000 & 0x100000. Search for $PIR and then save it before copying over the BIOS.
  
From Adam Sulmicki:
+
See also the [http://code.coreboot.org/p/coreboot-v1/source/tree/900/trunk/util/ADLO/README ADLO README] for more information.
 
I found beautfiul descrition of the BIOS implementation of the PIRQ in the red PCI book.
 
 
I found the description of the $PIR data structure in the
 
       
 
  http://www.microsoft.com/whdc/archive/pciirq.mspx
 
 
looking over linuxbios sources I see that it saves the $PIR data structure
 
somewhere between 0xf0000 & 0x100000.
 
 
so it seems I'll have to search for $PIR and then save it before copying
 
over our bios. sigh. hoped for some fixed address in mem.
 
 
--
 
Adam
 
http://www.eax.com      The Supreme Headquarters of the 32 bit registers
 
  
=== How do I set up etherboot with LinuxBIOS? ===
+
=== How do I set up etherboot with coreboot? ===
  
 
Note from Ron: I have edited this somewhat to remove Geode-specific items.  
 
Note from Ron: I have edited this somewhat to remove Geode-specific items.  
Line 386: Line 316:
 
  Cc: linuxbios@lanl.gov
 
  Cc: linuxbios@lanl.gov
 
  Subject: Re: LinuxBIOS + Etherboot HOWTO?
 
  Subject: Re: LinuxBIOS + Etherboot HOWTO?
 
 
   
 
   
 
  I had some trouble using LinuxBIOS + etherboot...  
 
  I had some trouble using LinuxBIOS + etherboot...  
 
 
   
 
   
 
  My bad, I messed up and used mkelfImage-1.6 that I got from ftp.lnxi.com, when I realized that I ought to use the one from freebios/util everything started working.  
 
  My bad, I messed up and used mkelfImage-1.6 that I got from ftp.lnxi.com, when I realized that I ought to use the one from freebios/util everything started working.  
 
 
   
 
   
 
  Here's what I did to get LinuxBIOS + Etherboot loading and booting a Linux kernel using TFTP.  
 
  Here's what I did to get LinuxBIOS + Etherboot loading and booting a Linux kernel using TFTP.  
 
 
   
 
   
 
   /Christer  
 
   /Christer  
 
 
   
 
   
 
  Get etherboot-5.0 from the CVS tree on etherboot.sourceforge.net.  
 
  Get etherboot-5.0 from the CVS tree on etherboot.sourceforge.net.  
 
 
   
 
   
 
  Modify etherboot-5.0/src/Config, comment out:  
 
  Modify etherboot-5.0/src/Config, comment out:  
Line 407: Line 331:
 
     # BIOS select don't change unless you know what you are doing
 
     # BIOS select don't change unless you know what you are doing
 
     #CFLAGS32+=    -DPCBIOS
 
     #CFLAGS32+=    -DPCBIOS
 
 
 
   
 
   
 
  and uncomment the following:  
 
  and uncomment the following:  
Line 415: Line 337:
 
     CFLAGS32+= -DLINUXBIOS -DCONFIG_TSC_CURRTICKS  -DCONSOLE_SERIAL \
 
     CFLAGS32+= -DLINUXBIOS -DCONFIG_TSC_CURRTICKS  -DCONSOLE_SERIAL \
 
               -DCOMCONSOLE=0x3f8 -DCOMPRESERVE -DCONFIG_PCI_DIRECT -DELF_IMAGE  
 
               -DCOMCONSOLE=0x3f8 -DCOMPRESERVE -DCONFIG_PCI_DIRECT -DELF_IMAGE  
 
 
 
   
 
   
 
  Compile Etherboot to make an elf file for your ethernet card:  
 
  Compile Etherboot to make an elf file for your ethernet card:  
 
   
 
   
 
     make bin32/natsemi.elf
 
     make bin32/natsemi.elf
 
 
 
   
 
   
 
  Compile and install mkelfImage from freebios/util/mkelfImage.  
 
  Compile and install mkelfImage from freebios/util/mkelfImage.  
 
 
   
 
   
 
  Create a bootimage to put on your TFTP server:  
 
  Create a bootimage to put on your TFTP server:  
Line 431: Line 348:
 
     mkelfImage --command-line="root=/dev/hda2 console=ttyS0,38400" \
 
     mkelfImage --command-line="root=/dev/hda2 console=ttyS0,38400" \
 
               --kernel vmlinux -o /tftpboot/kernel
 
               --kernel vmlinux -o /tftpboot/kernel
 
 
 
   
 
   
 
  Finally, make sure that your BOOT/DCHP server is answering and that the TFTP server is active.  
 
  Finally, make sure that your BOOT/DCHP server is answering and that the TFTP server is active.  
 
 
   
 
   
 
  Tell LinuxBIOS to boot an elf Image, and tell LinuxBIOS where it is:  
 
  Tell LinuxBIOS to boot an elf Image, and tell LinuxBIOS where it is:  
 
   
 
   
 
     option USE_ELF_BOOT=1
 
     option USE_ELF_BOOT=1
 
 
 
   
 
   
 
  I have placed natsemi.elf in the first 64k of my BIOS flash chip, and LinuxBIOS in the second 64k.  
 
  I have placed natsemi.elf in the first 64k of my BIOS flash chip, and LinuxBIOS in the second 64k.  
Line 449: Line 361:
 
     dd if=linuxbios.rom of=/dev/bios bs=64k seek=1
 
     dd if=linuxbios.rom of=/dev/bios bs=64k seek=1
 
   
 
   
+
  Finally boot LinuxBIOS.
 
  Finally boot LinuxBIOS.  
 
 
=== How do I set GEODE video? ===
 
 
 
Please see [http://www.openbios.org/pipermail/linuxbios/2002-November/001240.html here].
 
 
 
=== How do I set up testbios? ===
 
 
 
From daubin@actuality-systems.com Wed Oct  6 10:23:10 2004
 
Date: Tue, 5 Oct 2004 15:19:24 -0400
 
From: Dave Aubin
 
To: linuxbios@clustermatic.org
 
Subject: RE: Testbios help with nvidia 6800Gt and simple how to
 
 
I've taken the time to put together a simple testbios faq.
 
I hope it is helpful.  Feedback and additions are welcome.
 
 
Thanks,
 
Dave
 
 
==== Testbios (vgabios) Faq ====
 
  
Date: 10/5/2004
+
=== How do I set GEODE graphics and video? ===
Author(s): David Aubin  daubin@actuality-systems.com
 
  
Purpose:  Testbios is an i386 emulator that sits on top of userspace linux. It's primary purpose is to provide program video rom's in to the cached memory area.
+
There is no Geode graphics support in coreboot. Install the Geode framebuffer driver for console graphics and the X driver for X support on your Geode Linux image. Current kernel and X distributions contain the required drivers. Until the driver loads there is only serial console output.
  
===== Where to obtain testbios =====
+
Driver source:
  
Testbios(vgabios) can be retrieved from the linuxbios/freebios source tree: [http://www.linuxbios.org/developer/download/index.html]
+
[http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.23.y.git;a=tree;f=drivers/video/geode;hb=3968cb49ab01588cbf6896951780a1e411a0ec38 2.6.23 kernel framebuffer driver]
  
===== Prerequisites =====
+
[http://gitweb.freedesktop.org/?p=xorg/driver/xf86-video-amd.git;a=summary X.org driver]
  
You must have installed pci-utils
+
=== How do I set up testbios? ===
* Get http://atrey.karlin.mff.cuni.cz/~mj/pciutils.shtml
 
 
 
===== How to build testbios =====
 
* cd freebios/util/vgabios
 
* Edit ./Makefile and fill in the correct values for your environment (I build on a 64 AMD so my makefile looks like this)
 
 
 
Begin ./Makefile for x64:
 
CC      =  gcc
 
ARCH    := $(shell uname -m | sed -e s,i[3456789]86,i386,)
 
INCLUDE  =  -I ../pciutils-2.1.11
 
CFLAGS  =  -Wall -Ix86emu/include -O2 -g $(INCLUDE)
 
 
INTOBJS  =  int10.o int15.o int16.o int1a.o inte6.o
 
OBJECTS  =  testbios.o helper_exec.o helper_mem.o $(INTOBJS)
 
LDFLAGS  =  -static-libgcc -static
 
 
LIBS    =  x86emu/src/x86emu/libx86emu.a ../pciutils-2.1.11/lib/libpci.a
 
 
# user space pci is the only option right now.
 
OBJECTS += pci-userspace.o
 
 
ifeq ($(shell if test "$(ARCH)" == "x86_64" ; then echo 1; fi), 1)
 
        CFLAGS +=-m32 -march=i386
 
        endif
 
 
        all: testbios
 
 
        testbios: $(OBJECTS) $(LIBS)
 
                $(CC) $(CFLAGS) -o testbios $(OBJECTS) $(LDFLAGS)
 
$(LIBS)
 
 
helper_exec.o: helper_exec.c test.h
 
 
x86emu/src/x86emu/libx86emu.a:
 
        $(MAKE) -C x86emu/src/x86emu/ -f makefile.linux
 
 
        clean:
 
                $(MAKE) -C x86emu/src/x86emu/ -f makefile.linux clean
 
                rm -f *.o *~ testbios
 
 
        distclean: clean
 
                $(MAKE) -C x86emu/src/x86emu/ -f makefile.linux clean
 
 
 
End ./Makefile
 
 
 
* Edit ~vgabios/x86emu/src/x86emu/makefile.linux and fill in the correct values for your environment (I build on a 64 AMD so my makefile looks like this)
 
 
 
Begin ~vgabios/x86emu/src/x86emu/makefile.linux:
 
#############################################################################
 
#
 
#                                              Realmode X86 Emulator Library
 
#
 
#              Copyright (C) 1996-1999 SciTech Software, Inc.
 
#
 
#
 
<nowiki>========================================================================</nowiki>
 
#
 
#  Permission to use, copy, modify, distribute, and sell this software and
 
#  its documentation for any purpose is hereby granted without fee,
 
#  provided that the above copyright notice appear in all copies and that
 
#  both that copyright notice and this permission notice appear in
 
#  supporting documentation, and that the name of the authors not be used
 
#  in advertising or publicity pertaining to distribution of the software
 
#  without specific, written prior permission.  The authors makes no
 
#  representations about the suitability of this software for any purpose.
 
#  It is provided "as is" without express or implied warranty.
 
#
 
#  THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 
#  INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 
#  EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 
#  CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
 
#  USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 
#  OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 
#  PERFORMANCE OF THIS SOFTWARE.
 
#
 
#
 
<nowiki>========================================================================</nowiki>
 
#
 
# Descripton:  Linux specific makefile for the x86emu library.
 
#
 
#############################################################################
 
 
TARGETLIB = libx86emu.a
 
 
 
OBJS=\
 
debug.o \
 
decode.o \
 
fpu.o \
 
ops.o \
 
ops2.o \
 
prim_ops.o \
 
sys.o
 
 
$(TARGETLIB): $(OBJS)
 
        ar rv $(TARGETLIB) $(OBJS)
 
 
        INCS  = -I. -Ix86emu -I../../include
 
        CFLAGS += -D__DRIVER__ -DFORCE_POST -D_CEXPORT= -DNO_LONG_LONG -DDEBUG
 
        ARCH  := $(shell uname -m | sed -e s,i[3456789]86,i386,)
 
        ifeq ($(shell if test "$(ARCH)" == "x86_64" ; then echo 1; fi), 1)
 
                CFLAGS +=-m32 -march=i386
 
                endif
 
 
 
.c.o:
 
#      gcc -m32 -march=i386 -g -O -Wall -c $(CFLAGS) $(INCS) $*.c
 
        gcc -g -O -Wall -c $(CFLAGS) $(INCS) $*.c
 
 
.cpp.o:
 
#      gcc -m32 -march=i386 -c $(CFLAGS) $(INCS) $*.cpp
 
        gcc -c $(CFLAGS) $(INCS) $*.cpp
 
 
clean:
 
        rm -f *.a *.o
 
 
validate:      validate.o libx86emu.a
 
        gcc -o validate validate.o -lx86emu -L.
 
 
End ~vgabios/x86emu/src/x86emu/makefile.linux
 
 
 
* Once built you could have a 32bit testbios executable made. Depending on your embedded environment you might want to have it built shared as the above example makes it static.  Just remove -static-libgcc -static from the LDFLAGS on ./Makefile if you wish to have it built shared.
 
 
 
===== How to retrieve a good video bios =====
 
 
 
Note: if you are following these instructions to build LinuxBIOS for your motherboard, this is only necessary if you have a motherboard with an embedded VGA card. If your VGA is an add-on card, LinuxBIOS will find and run the ROM by itself.
 
 
 
Anton Borisov has released a number of tools under the GPL (v2) to extract the VGA BIOS from the BIOS ROM images provided by the supplier of your motherboard.
 
 
 
You can download them here:
 
 
 
  Award BIOS: http://kaos.ru/biosgfx/download/awardeco-0.2.src.tar.gz
 
  AMI BIOS: http://www.kaos.ru/biosgfx/download/AmiDeco_0.31e.src.tar.gz
 
  Insyde BIOS: http://www.kaos.ru/biosgfx/download/InsyDeco_0.3.src.tar.gz
 
  Phoenix BIOS: http://www.kaos.ru/biosgfx/download/PhoenixDeco_0.33.src.tar.gz
 
 
 
See the [[Tyan S2881 Build Tutorial]] for more information on how to use these tools.
 
 
 
Alternatively, there are sites that have video bios roms on their website. Google is your friend, as always.
 
 
 
In some cases, you should also be able to retrieve your own video bios while running linux. Note however that this does NOT always work. In the case of the Tyan s2881, for instance, this method will generate a 32KB VGA ROM image that is invalid - the real VGA ROM image is 36K long, but the last 4K is not available in RAM, and thus can not be extracted with the following method.
 
 
 
* Boot up a machine with a commercial bios (not linux bios) with the video card you wish to work under linux bios.
 
 
 
You can see where your vga bios starts and how much space it takes by issuing
 
 
 
  <code>cat /proc/iomem | grep "Video ROM"</code>
 
 
 
* To extract the bios, enter this command on the command line:<br />
 
 
 
  dd if=/dev/mem of=vgabios.bin skip=1536 count=128
 
 
 
Alternatively, you could use:<br />
 
 
 
  dd if=/dev/mem of=vgabios.bin bs=1k skip=768 count=64
 
 
 
This assumes you card's bios is cached in 0xc0000, and is 64K long. If your bios starts at 0xc0000 and ends at 0xc7fff it is only 32K long, and you need this command:<br />
 
 
 
  dd if=/dev/mem of=vgabios.bin bs=1k skip=768 count=32
 
 
 
*** dd Explained (man dd to learn more):
 
****  if is the location to retrieve from.
 
****  of is the output file (your rom image)
 
****  bs is the block size (the default is 512 bytes)
 
****  skip jumps n blocks in the source data
 
****  count is how many blocks you wish to read
 
** You now have a video bios image
 
 
 
===== How to use testbios =====
 
* Currently testbios only works from user space linux (10/4/04)
 
* Example from a linux command line or script enter the following to get your video bios programmed:<br /><code>./testbios -d 0x90 -s 65536 --abseg /dev/mem ./vgabios.bin</code>
 
** Testbios explained
 
***  -s  how much of the video bios is there
 
***  --abseg where would you like to write this (/dev/mem default)
 
***  -d device busdevfun in packed from
 
****  How to get pci busdevfn in packed notation
 
****  lspci
 
****  look for your video card
 
***** Example:<br /><code>2:00:00<br />2 (00 << 3) | 00 = 0x200</code>
 
***** Example:<br /><code>00:12.0:<br />0 (12 << 3) | 0 = 0x90</code>
 
*** -t dump
 
*** -c codesegment Where do you want to start, default is 0xc0000
 
*** -b base  Where do you want base to be default is 0xc000
 
*** -i instruction pointer usually left off as the default
 
***  filename of video bios
 
 
 
==== Followup to Testbios FAQ ====
 
  
See [http://www.openbios.org/pipermail/linuxbios/2004-October/009106.html the thread starting here].
+
Please read the [http://coreboot.org/FAQ/Obsolete#How_do_I_set_up_testbios.3F testbios FAQ].
  
 
=== /usr/sbin/iasl: Command not found ===
 
=== /usr/sbin/iasl: Command not found ===
Line 682: Line 383:
 
* '''SUSE''' ships it in the '''pmtools''' package ([ftp://ftp.gwdg.de/pub/opensuse/distribution/SL-10.0-OSS/inst-source/suse/x86_64/pmtools-20050823-3.x86_64.rpm pmtools-20050823-3.x86_64.rpm], [ftp://ftp.gwdg.de/pub/opensuse/distribution/SL-10.0-OSS/inst-source/suse/i586/pmtools-20050823-3.i586.rpm pmtools-20050823-3.i586.rpm]). If you want to run rpmbuild --rebuild: [ftp://ftp.gwdg.de/pub/opensuse/distribution/SL-10.0-OSS/inst-source/suse/src/pmtools-20050823-3.src.rpm pmtools-20050823-3.src.rpm].
 
* '''SUSE''' ships it in the '''pmtools''' package ([ftp://ftp.gwdg.de/pub/opensuse/distribution/SL-10.0-OSS/inst-source/suse/x86_64/pmtools-20050823-3.x86_64.rpm pmtools-20050823-3.x86_64.rpm], [ftp://ftp.gwdg.de/pub/opensuse/distribution/SL-10.0-OSS/inst-source/suse/i586/pmtools-20050823-3.i586.rpm pmtools-20050823-3.i586.rpm]). If you want to run rpmbuild --rebuild: [ftp://ftp.gwdg.de/pub/opensuse/distribution/SL-10.0-OSS/inst-source/suse/src/pmtools-20050823-3.src.rpm pmtools-20050823-3.src.rpm].
 
* '''Debian''' ships it in the '''iasl''' package (''apt-get install iasl'').
 
* '''Debian''' ships it in the '''iasl''' package (''apt-get install iasl'').
* You can also download the [http://www.intel.com/technology/iapc/acpi/downloads.htm latest version of the source code].
+
* You can also download the [http://acpica.org/downloads/unix_source_code.php latest version of the source code].
 
 
=== How can I write to port 0x80 from userspace? ===
 
  
[http://www.linuxbios.org/pipermail/linuxbios/2006-November/017012.html This] might be useful sometimes:
+
=== How can I write to POSTcard port 0x80 from userspace? ===
 +
[https://mail.coreboot.org/pipermail/coreboot/2006-November/017091.html This] might be useful in some situations, and to output a number to a POST card:
  
 
  printf "\001" | dd bs=1 seek=128 of=/dev/port
 
  printf "\001" | dd bs=1 seek=128 of=/dev/port
  
== Probably Obsolete Items ==
+
or using [https://github.com/adurbin/iotools iotools]:
 +
iotools io_write8 0x80 0x42
  
=== How do I burn a DoC? ===
+
In case of linux commands above do output to POST card, but the value is immediately replaced by 0x00 due to [https://github.com/torvalds/linux/blob/v4.2/arch/x86/boot/boot.h#L78 io_delay]. Further explanations can be found on [https://lists.gt.net/linux/kernel/260809 kernel mailinglist archive]
  
Currently, only the DoC Millennium is supported. See the documentation.
 
  
=== How do I put a filesystem on DoC? ===
+
In DOS (not Windows XP) use:
OK, here is a little HOWTO on how to set up MTD with a file system.  
+
mov al, 42; out al, 80h
 +
To output 42 type
 +
o 80 42
 +
in DOS [http://help.fdos.org/en/hhstndrd/base/debug.htm debug.exe].
  
This is a m810lmr, booting out of DoC. I am going to reserve the first 2M for kernel. So the layout will be the first 2M for linuxbios and kernel, and 6M for a file system. Kernel is 2.4.17, with linux-2.4.17-sis.patch from linuxbios source tree, and config-2.4.17-sis from the linuxbios source tree. Mainboard is the pcchips m810lmr.  
+
When using LPT (parallel port) POST card - write to port assigned to parallel port, eg. 0x3BC, 0x378, 0x278. Some SuperIOs/EmbeddedControllers will decode 0x80 like ENE KB926
  
So I:
+
=== Is coreboot applying x86 microcode patches? ===
modprobe doc2001
 
modprobe docprobe
 
dmesg
 
  
which shows:
+
And if yes, can they be modified?
  
DiskOnChip Millennium found at address 0xFFFC8000
+
Answer: Yes, coreboot is applying microcode patches on AMD and Intel CPUs. However, this field is little documented, so coreboot uses only unmodified, vendor-provided microcode. Few people think, that system design can seriously be improved by modifications here ( �Code patches mostly disable erraneous functions and opcodes).
Flash chip found: Manufacturer ID: 98, Chip ID: E6 (Toshiba TC58V64AFT/DC)
 
1 flash chips found. Total DiskOnChip size: 8 MiB
 
mtd: Giving out device 0 to DiskOnChip Millennium
 
Ignoring DiskOnChip Millennium at 0xFFFCA000 - already configured
 
Ignoring DiskOnChip Millennium at 0xFFFCC000 - already configured
 
Ignoring DiskOnChip Millennium at 0xFFFCE000 - already configured
 
Ignoring DiskOnChip Millennium at 0xFFFD0000 - already configured
 
Ignoring DiskOnChip Millennium at 0xFFFD2000 - already configured
 
Ignoring DiskOnChip Millennium at 0xFFFD4000 - already configured
 
Ignoring DiskOnChip Millennium at 0xFFFD6000 - already configured
 
(etc..)
 
Now I need MTD utilities.
 
So I:
 
cvs -d :pserver:anoncvs@cvs.infradead.org:/home/cvs login
 
CVS password:
 
 
(password is anoncvs)  
 
Then:
 
cvs -d :pserver:anoncvs@cvs.infradead.org:/home/cvs co mtd
 
  
Forget the drivers and such, you don't need them. What you need is the tools.
+
=== How can I retrieve a good video BIOS? ===
cd mtd/tools
 
make
 
  
Go ahead and copy the executables somewhere handy, you'll need them.  
+
Note: If you are following these instructions to build coreboot for your motherboard, this is only necessary if you have a motherboard with an embedded VGA card. If your VGA is a PCI / PCI-Express add-on card, coreboot will find and run the ROM by itself.
  
Now we need to make the last 6M into a "disk". We need to format it. The tool is nftl_format, so:
+
See [[VGA_support]] for the details.
  
[root@carly util]# ./nftl_format
+
<!--- Anton Borisov has released a number of tools under the GPL (v2) to extract the VGA BIOS from the BIOS ROM images provided by the supplier of your motherboard.
$Id: nftl_format.c,v 1.17 2001/08/29 14:28:48 dwmw2 Exp $
 
Usage: ./nftl_format [ []]
 
[root@carly util]# expr 2048 \* 1024
 
2097152
 
[root@carly util]# expr 6 \* 1024 \* 1024
 
6291456
 
[root@carly util]# ./nftl_format /dev/mtd0 2097152 6291456
 
$Id: nftl_format.c,v 1.17 2001/08/29 14:28:48 dwmw2 Exp $
 
Phase 1. Checking and erasing Erase Zones from 0x00200000 to 0x00800000
 
Phase 2.a Writing NFTL Media Header and Bad Unit Table
 
Phase 2.b Writing Spare NFTL Media Header and Spare Bad Unit Table
 
Phase 3. Writing Unit Control Information to each Erase Unit
 
  
 +
You can download them here:
  
we now have a formatted disk in there. We can now partition it.  
+
* Award BIOS:
 +
** http://kaos.ru/biosgfx/download/awardeco-0.2.src.tar.gz
 +
** http://ftp.debian.org/debian/pool/main/a/awardeco/awardeco_0.2.orig.tar.gz
 +
* AMI BIOS:
 +
** http://www.kaos.ru/biosgfx/download/AmiDeco_0.31e.src.tar.gz
 +
** http://ftp.debian.org/debian/pool/main/a/amideco/amideco_0.31e.orig.tar.gz
 +
* Phoenix BIOS:
 +
** http://www.kaos.ru/biosgfx/download/PhoenixDeco_0.33.src.tar.gz
 +
** http://ftp.debian.org/debian/pool/main/p/phnxdeco/phnxdeco_0.33.orig.tar.gz
 +
* Insyde BIOS:
 +
** http://www.kaos.ru/biosgfx/download/InsyDeco_0.3.src.tar.gz
 +
** (no alternative download location available, sorry)
  
[root@carly util]# modprobe nftl
+
See the [[Tyan S2881|Tyan S2881 Build Tutorial]] for more information on how to use these tools.
 +
--->
  
dmesg shows LOTS of errors, since this was never partitioned ...
+
== Errors ==
  
Also, if you don't have /dev/nftla,
+
=== ERROR: Not enough MTRRs available! ===
 +
There are 8 dynamic MTRRs available on x86.
  
[root@carly util]# mknod /dev/nftla b 93 0
+
This message tells you that there's an error with PCI device resources.
  
 +
It might be an error in the PCI handling code or the devicetree.
  
Don't use the script just yet, it makes /dev/nftla as b 93 16, which is the wrong unit #.
+
== Can I put coreboot into a PCI expansion ROM? ==
  
now fdisk /dev/nftla
+
Short answer: NO.
  
[root@carly util]# fdisk /dev/nftlA
+
Long answer:
Command (m for help): n
 
Command action
 
e extended
 
p primary partition (1-4)
 
p
 
Partition number (1-4): 1
 
First cylinder (1-1, default 1):
 
Using default value 1
 
Command (m for help): p
 
Disk /dev/nftlA: 1 heads, 12224 sectors, 1 cylinders
 
Units = cylinders of 12224 * 512 bytes
 
Device Boot Start End Blocks Id System
 
/dev/nftlA1 1 1 6111+ 83 Linux
 
Partition 1 has different physical/logical endings:
 
phys=(768, 0, 0) logical=(0, 0, 12224)
 
Partition 1 does not end on cylinder boundary:
 
phys=(768, 0, 0) should be (768, 0, 12224)
 
Command (m for help): w
 
The partition table has been altered!
 
Calling ioctl() to re-read partition table.
 
WARNING: If you have created or modified any DOS 6.x partitions, please see the fdisk manual page for additional information.
 
Syncing disks.
 
[root@carly util]# mknod /dev/nftlA1 b 93 1
 
[root@carly util]# mke2fs /dev/nftlA1
 
mke2fs 1.23, 15-Aug-2001 for EXT2 FS 0.5b, 95/08/09
 
Filesystem label=
 
OS type: Linux
 
Block size=1024 (log=0)
 
Fragment size=1024 (log=0)
 
1528 inodes, 6111 blocks
 
305 blocks (4.99%) reserved for the super user
 
First data block=1
 
1 block group
 
8192 blocks per group, 8192 fragments per group
 
1528 inodes per group
 
Writing inode tables: done
 
Writing superblocks and filesystem accounting information: done
 
  
This filesystem will be automatically checked every 37 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override.  
+
There's little use in doing that, as a lots of initialization has already been done by the proprietary BIOS (or coreboot) by the time the PCI expansion ROM is executed. It won't be possible to run coreboot from a PCI expansion ROM after a proprietary BIOS has already been running for instance.
  
[root@carly util]# mount /dev/nftlA1 /mnt
+
Note: The Intel ICH7 southbridge seems to allows booting from PCI ROMs ('''not''' arbitrary PCI expansion ROMs as used on graphics cards, SCSI controllers, etc.) -- maybe this should be investigated in order to check if or how it might be useful.
[root@carly util]# cd /mnt
 
[root@carly mnt]# df .  
 
Filesystem 1k-blocks Used Available Use% Mounted on
 
/dev/nftlA1 5915 13 5597 1% /mnt
 
[root@carly mnt]#
 
  
and so you now have an ext2 file system on the DoC.
+
== Obsolete FAQ items ==
  
(Above is from [[User:Rminnich|Ron Minnich]])
+
Please see [[FAQ/Obsolete]] for (probably) obsolete FAQ items.

Latest revision as of 18:41, 5 March 2018

Contents

General

What is coreboot?

coreboot (formerly known as LinuxBIOS) is a Free Software project aimed at replacing the proprietary BIOS (firmware) you can find in most of today's computers.

It performs just a little bit of hardware initialization and then executes what is called a payload.

Some of the many possible payloads are: a Linux kernel, FILO (a GRUB-like bootloader for booting from disk), GRUB2, Open Firmware, Etherboot/GPXE, SeaBIOS (for booting Windows XP, Windows Vista, Windows 7, NetBSD and Linux), and many others.

The initial motivation for the project was maintenance of large clusters, but unsurprisingly, interest and contributions have come from people with varying backgrounds. The latest version of coreboot can be used in a wide variety of scenarios including clusters, embedded systems, desktop PCs, servers, and more.

For more information, see History.

Why do we need coreboot?

Why do we need coreboot for cluster maintainance?

Current PCs used as cluster nodes depend on a vendor-supplied BIOS for booting. The BIOS in turn relies on inherently unreliable devices such as floppy disks and hard drives to boot the operating system. In addition, current BIOS software is unable to accommodate non-standard hardware making it difficult to support experimental work. The BIOS is slow and often erroneous and redundant and, most importantly, maintenance is a nightmare. Imagine walking around with a keyboard and monitor to every one of the 128 nodes in a cluster to change one BIOS setting.

coreboot with Linux as a payload (other payloads are possible!) gunzip's the Linux kernel straight out of NVRAM and essentially requires no moving parts other than the CPU fan. It does a minimal amount of hardware initialization before jumping to the kernel start and lets Linux do the rest. As a result, it is much faster (current record: 3 seconds), which has sparked interest in the consumer electronics community as well. Moreover, updates can be performed over the network.

Using a real operating system to boot another operating system provides much greater flexibility than using a simple netboot program or the BIOS. Because Linux is the boot mechanism, it can boot over standard Ethernet or over other interconnects such as Myrinet, Quadrics, or SCI. It can use SSH connections to load the kernel, or it can use the InterMezzo caching file system or traditional NFS. Cluster nodes can be as simple as they need to be — perhaps as simple as a CPU and memory, no disk, no floppy, and no file system. The nodes will be much less autonomous thus making them easier to maintain.

Why do we need coreboot for other purposes?

Some aspects of DRM are not travelling well with the idea of a free computer system. As many computer magazines already pointed out, there may be future restrictions imposed by BIOSes, that a customer is little aware of before purchase and might not harmonize with the idea of freedom and/or security in some cases.

Who is working on coreboot?

The coreboot project was started in the winter of 1999 in the Advanced Computing Laboratory at Los Alamos National Laboratory (LANL) by Ron Minnich. Two undergraduate students, James Hendricks and Dale Webster spent their winter vacation putting together the proof of concept implementation.

Since then, a long list of people have contributed both in discussions and actual code. Please don't be shy and let us know if you are missing from the list. It's not a purposeful omission, just an unfortunate mistake.

Who is funding coreboot?

The coreboot project was initially funded by the Los Alamos Computer Science Institute and the Department of Energy's Office of Science.

See also the list of coreboot sponsors.

Users

Will coreboot work on my machine?

See the Supported Motherboards page for which mainboards are supported, and also the list of Supported Chipsets and Devices. See the Products page for a list of vendors selling products running coreboot. Finally, you could look at the coreboot source tree, in src/mainboard.

If your board is not already supported, it will likely take you years of work to port coreboot to operate correctly on it unless you have experience with firmware level C development and good knowledge of the underlying (x86 or ARM) architecture.

If you do not see your board in the above sources, please send the following to the mailing list:

  • Step 1: A very brief description of your system: board vendor, board name, CPU, northbridge, southbridge, and optionally other important details.
  • Step 2: Linux "lspci -tvnn" output for your system, generated by booting Linux via the original BIOS and runnning lspci.
  • Step 3: Super I/O chip on the mainboard (report the model numbers on the actual chip, for example "Winbond W83627HF" and/or run "superiotool -dV").
  • Step 4: Type of BIOS device (see the question "How do I identify the BIOS chip on my mainboard?" below). Please send us the output of "flashrom -p internal -V"
  • Step 5: URL to the mainboard specifications page (optional).
  • Step 6: Any other relevant information you can provide.

If you can't do step 1 above, please describe (as best you can) the specific CPU chip and the chipset used on the mainboard.

Usually in less than a day, someone will respond on the coreboot mailing list, most often with bad news. However it is possible that your mainboard is supported in the main coreboot source tree, or that support is currently in development, so it won't hurt to ask. It's also possible (and unfortunately, likely) that the manufacturer will not release information needed to provide coreboot support. In the latter case, please let the manufacturer know that you want coreboot support and his failure to release chipset information is making that very difficult.

What commercial products use coreboot?

See the products page.

Which different operating systems will coreboot boot?

coreboot should support almost any modern operating system. To support operating systems that use BIOS calls, SeaBIOS is mandantory, as coreboot doesn't provide these by itself:

  • Linux
  • Plan 9
  • FreeDOS (via SeaBIOS)
  • Windows 2000, XP, Vista, 7(RC) (via SeaBIOS, the boot loader requires BIOS)
  • NetBSD, MirBSD (via SeaBIOS as at least the boot loader requires BIOS)

coreboot does not natively support:

  • We have tested some of the BSD OSes and have seen, that FreeBSD for example makes BIOS calls, which is not supported by coreboot. Possibly with help of SeaBIOS, it may be possible to boot FreeBSD like it is now, but the right thing to do, is to remove FreeBSD's dependence on BIOS calls.
  • Windows versions older than Windows 2000, as they make BIOS calls (SeaBIOS might help)
  • MenuetOS, as it makes BIOS calls (SeaBIOS might help)

Please feel free to test booting any of the above using SeaBIOS and report to the coreboot mailing list.

What chipsets and Super I/O devices are supported?

See the Supported Chipsets and Devices page.

Where is the mailing list archived?

See Mailinglist.

Is there a coreboot IRC channel?

Yes, see IRC.

Where do I get the code?

See the download page.

How do I build coreboot?

See the Build HOWTO.

How can I help with coreboot?

There are many ways how you can help us:

  • You can ask for a Wiki account. Send a private message with your preferred username and email to pgeorgi or stefanct in the #coreboot IRC channel at freenode.net.
  • Promote coreboot, tell all your friends about it, blog about it etc.
  • Test coreboot, report any bugs you find to our mailinglist or to our bug tracker, or let us know about any suggestions for improvements you have.
  • Help us to make the list of Supported Motherboards and the list of Supported Chipsets and Devices bigger by contributing code. Please also read the Development Guidelines in that case.
  • If you have a mainboard with USB2 (EHCI-controller) you can look if it supports the EHCI Debug Port and mail the information to us, if it is not already there.
    • If you are familiar with microcontroller development, you might be able to build a debugging tool for the EHCI Debug Port. If you are successful, we like to hear about it.
  • Test, if QNX or Solaris are able to boot on a mainboard with coreboot.
  • Have a look at the list of open issues/bugs in our mailinglist (as current bug tracker is dead) and try to reproduce them or (preferrably) fix them.
  • Contact Ron Minnich or Stefan Reinauer for bigger projects related to coreboot.
  • Contact us on the mailing list if you have any further questions or suggestions.

What do the abbreviations in this wiki stand for?

See Glossary.

Can I play the latest PC games on a coreboot platform?

Of course.

The current performance coreboot compatible x86-64 motherboard is the KGPE-D16 which has dual PCI-e x16 2.0 slots, 192GB max RAM and can support fast CPU's such as the G34 16 core Opteron 6386SE, 6287SE and 6284SE - with one of those the bottleneck will be always be GPU related if you are playing a highly multi-threaded game.

If you aren't using the computer for something very important you can save a lot of money and have an affordable libre firmware gaming platform by getting a used CPU. You can even use IOMMU-GFX to have multiple separate VM's and thus have more than one player on the same machine (needs one gfx card per VM)

If you do not want to have to buy an SSI-EEB compatable case there is also the KCMA-D8 which is the KGPE-D16's regular ATX little brother, although the CPU's max out at 8 cores per and there aren't as many PCI-e slots (no dual x16 so no crossfire).

NOTE: game needs to be highly multithreaded due to poor c32/g34 opteron single threaded performance, having half core turbo functional helps with this. Thus brand new and old games work great but games from 3-6 years ago may work poorly.

Opteron C32/G34 CPU's to buy for gaming:

G34 16 core: 6386SE 6287SE 6284SE

G34 8 Core: 6328 (approx FX-8310)

C32 8 Core 4386

Note: On multi CPU or 16 core setups you will have poor performance and stuttering if your OS does not properly allocate NUMA memory.

Developers

Where can I buy BIOS chips (empty or pre-flashed)?

When developing or simply trying out coreboot you always need a means to revert to your old BIOS in case something goes wrong. One way to do this is to get an extra BIOS chip (PLCC32, DIP32, DIP8, or other) and copy your original BIOS image onto that chip (using flashrom, for example). If you have a socketed BIOS (not soldered onto the mainboard), you can hot-swap the chips while your computer is running (Do not hot swap with your hands - You must use an insulated chip removal tool to avoid a short-circuit)

You have several options to get spare BIOS chips:

What kind of hardware tools do I need?

See the hardware tools section of the developer's manual.

How do I use a null-modem cable to get coreboot debugging output over a serial port?

  • First, you'll want to set up a terminal program, e.g. minicom correctly.
$ minicom -s
 -> Serial port setup
 -> Press A and enter your COM device (ttyS0 or ttyS1 or ttyUSB0, depending on your COM port)
 -> Press E and choose "115200 8N1" (default)
 -> Disable Hardware and Software Flow Control (via F and G)
 -> Press enter to leave the menu
 -> Save setup as..
 ->   Enter "lb"
 -> Exit from minicom
  • From now on, you can start minicom with the obove settings simply by typing:
$ minicom -o lb

What documentation do I need?

As much documentation as you can possibly get your hands on. At minimum, you will need the docs for the chipset.

There have been reports of people getting coreboot working by booting with the OEM BIOS. Then, they would read the static contents of the PCI config registers after boot. coreboot is then built to match the static contents read from the PCI config registers.

The problem with this approach is that chipsets generally require dynamic vs static configuration values during their initialization. The configuration register contents will change from one stage of initialization to the next. Since the contents of the registers read is only the final state of the configuration registers, the chipset won't be properly initialized if these are the only configuration values used.

Getting a mainboard up without chipset docs can be a very long and involved process.

What if my chipset docs are covered by an NDA?

If the documentation for your chipset covered by a NDA with no source release agreement, you won't be able to release your code back to the coreboot project in general, or you will violate the GPL. Many vendors accept releasing the source code, produced after reading such specs, while they don't allow the specs themselves to be revealed. Also, you can offer them the opportunity to review your code, before releasing it to the public.

Why is the code so complicated and what can I do to make it easier?

The reason is the complexity of the problem. We support a lot of hardware, and a given chip on a given board will most likely not be configured quite the same as the same chip on some other board. To help make code navigation easier, pick a target and build that target. Then, in the build directory, type make tags or make etags to get your favorite tags file.

How do I contribute my changes?

Please carefully read the Development Guidelines for more information.

How do I identify the BIOS chip on my mainboard?

Please see [1].

How do I (re-)flash the BIOS?

Out of mainboard BIOS (re)flash

If the BIOS chip is socketed, it can be removed and flashed in a rom/flash burner and quickly re-installed.

You have the option of using the external programmers supported by flashrom or some other external programmer which comes with its own software. Depending on the flash chip type, various options exist. For older parallel flash chips, some of these burners cost $700 and more plus they complete a flash in 30 seconds (like the Conitec Galep V), but if you are willing to wait 5 minutes for a flash and manually set DIP switches, the Enhanced Willem Universal Programmer will do the job for only $40-60 USD. There are several models of the Willem Programmer, each supporting many chips, but not all, so be sure to get one that supports your BIOS chip. You could also use the Paraflasher which is a really low-cost programmer with parts sold for $20 or less. The flashrom wiki has a list of hardware you can use for programming.

If your chip is PLCC, you will also need the push pin trick or a PLCC chip extractor/puller or just thread nylon string under the PLCC chip from corner to corner and yank up it straight up. Read more about chip extraction in the developer manual.

Inside mainboard BIOS (re)flash

Download the appropriate flash update utility. Build the coreboot image as explained above and use the flash update utility to update the BIOS. Be warned that not all update utilities allow you to load your own BIOS image. NOTE: Many vendor specific flash utilities refuse to write "foreign" BIOS images, such as coreboot.

Therefore we suggest that you use the universal flash utility called flashrom which was developed and improved by many coreboot developers, and it works under Linux/*BSD/MacOSX/Solaris/DOS.

Example:

bash$ sudo ./flashrom -V
flashrom v0.9.2-r1000 on Linux 2.6.34-rc7-git5 (x86_64), built with libpci 3.1.7, GCC 4.4.3
flashrom is free software, get the source code at http://www.flashrom.org

No coreboot table found.
Found chipset "Intel ICH9", enabling flash write... OK.
This chipset supports the following protocols: FWH,SPI.
Calibrating delay loop... 663M loops per second, 100 myus = 199 us. OK.
Found chip "Winbond W25x80" (1024 KB, SPI) at physical address 0xfff00000.
No operations were specified.

Alternatively you could either use the DOS uniflash utility, or use its source code, which is also available for download from the uniflash site (in Turbo Pascal 7) as a reference for adding support for your flash chip to flashrom. Uniflash supports a lot of different flash chips, and chip interfaces, but so far SPI support is only present in flashrom. You can use flashrom and uniflash for PCI expansion card flashing, such as on RTL8139 Ethernet card (32pin DIL), which allows flashing of your BIOS chip on the NIC if manufacturer provides the circuitry. Please note that flashrom and uniflash support different cards and you should check which utility supports the programmer hardware you own.

Another tool which runs in linux is ctflasher, but it is not maintained anymore and might not work with current Linux kernels.


BIOS Savior RD1

BIOS Savior RD1

There are some posts about the BIOS Savior RD1 that suggest its integrated flash device is of low quality; it may take 10 or more flash programming attempts to get a good update to the RD1 flash device. As a result, the following steps have proven to be successful while using the RD1:

  • Step 1 - While the system is powered down, remove the original BIOS device from the mainboard and insert it into the RD1's socket.
  • Step 2 - Insert the RD1 into the mainboard's flash BIOS socket.
  • Step 3 - Boot the system with the RD1 set to boot from the original flash device from the mainboard.
  • Step 4 - Program the original BIOS image (or other known good BIOS image) into the RD1's integrated flash device. Do this as many times as needed until the device is properly programmed and the system boots corectly from the RD1's integrated flash device. Be sure to check the settings on the RD1 so that the proper flash device is now being programmed. If the RD1 is not set correctly the working BIOS image will be erased and the system will not boot!
  • Step 5 - Program the test BIOS image (usually coreboot images are among this group) into the original flash device from the mainboard. The original BIOS device usually programs OK on the first attempt. Be sure to check the settings again on the RD1 so that the proper flash device is being programmed!


The RD1 has been used in the above fashion with great success on the Tyan S2885 mainboard. Unfortunately the RD1 does not work on the nVidia CK8-04 CRB mainboard. The CK8-04 CRB may require a flash device that the RD1 does not support.

The RD1 has worked well as a "do nothing" adapter that allows swapping the BIOS flash device between a flash burner and a mainboard without any wear to the mainboard's BIOS socket.

Can I do any serious damage mucking around with this stuff?

Any time you stick your hand into an open machine while the power is on, you're risking life and limb. That said, there are also some other not-so-nice things that can happen if you mess up (not that we would know).

  • Incorrect insertion of the flash (1 casualty)
  • Incorrect jumper settings (1 casualty)
  • Aggressive and/or inappropriate use of metal objects such as screwdrivers (2 casualties)
  • Miscellaneous miswirings and mishandlings (3+ casualties)

remember: make sure your important data is on a disconnected drive while you experiment.

A note on electrostatic discharge (ESD) and ESD protection (thanks to Bari Ari)

ESD can damage disk drives, boards, DoC's and other parts. The majority of the time, ESD events cause the component to degrade, but not fail testing procedures, resulting in failure at a later date. Because components do not fail immediately, technicians often underestimate the cost of not using ESD prevention measures. Provide at minimum some ESD protection by wearing an antistatic wrist strap attached to the chassis ground on your system when handling parts.

Always handle boards carefully. They can be extremely sensitive to ESD. Hold boards only by their edges. After removing a board from its protective wrapper or from the system, place it component side up on a grounded, static free surface. Use a conductive foam pad if available. Do not slide the board over any surface.

To further reduce the chances of ESD, you should create an ESD safe workstation that includes at minimum:

  • Conductive rubber mat, with a lead wire that can be connected to a metal surface to create a ground.
  • ESD wrist strap, which has a resistor inside the strap and a lead wire that can be connected to a metal surface as a ground. The grounding wire on the wrist strap should have between 1 and 10 Megaohms of resistance. The resistor should protect you in case you come in contact with a voltage source. If the resistor is bad or not included, the wrist strap is useless. An accidental shock could be serious and even deadly!
  • Table or workspace that is clean, clear of dust, and away from electrical machinery or other equipment that generates electrical currents.

The idea is to ensure that all components you are going to interact with have the same charge. By connecting everything to the computer case, you ensure that the components of the case, the chair, and your body all have the same charge. If every object has the same charge, the electrons will not jump from one object to another minimizing the risk of ESD damage.

What is a PIRQ table?

There's a good description of the BIOS implementation of the PIRQ in the red PCI book, and here's a description of the $PIR data structure.

coreboot saves the $PIR data structure between 0xf0000 & 0x100000. Search for $PIR and then save it before copying over the BIOS.

See also the ADLO README for more information.

How do I set up etherboot with coreboot?

Note from Ron: I have edited this somewhat to remove Geode-specific items.

Christer Weinigel writes: 
To: rminnich@lanl.gov
Cc: linuxbios@lanl.gov
Subject: Re: LinuxBIOS + Etherboot HOWTO?

I had some trouble using LinuxBIOS + etherboot... 

My bad, I messed up and used mkelfImage-1.6 that I got from ftp.lnxi.com, when I realized that I ought to use the one from freebios/util everything started working. 

Here's what I did to get LinuxBIOS + Etherboot loading and booting a Linux kernel using TFTP. 

  /Christer 

Get etherboot-5.0 from the CVS tree on etherboot.sourceforge.net. 

Modify etherboot-5.0/src/Config, comment out: 

   # BIOS select don't change unless you know what you are doing
   #CFLAGS32+=     -DPCBIOS

and uncomment the following: 

   # Options to make a version of Etherboot that will work under linuxBIOS.
   CFLAGS32+= -DLINUXBIOS -DCONFIG_TSC_CURRTICKS  -DCONSOLE_SERIAL \
              -DCOMCONSOLE=0x3f8 -DCOMPRESERVE -DCONFIG_PCI_DIRECT -DELF_IMAGE 

Compile Etherboot to make an elf file for your ethernet card: 

    make bin32/natsemi.elf

Compile and install mkelfImage from freebios/util/mkelfImage. 

Create a bootimage to put on your TFTP server: 

   mkelfImage --command-line="root=/dev/hda2 console=ttyS0,38400" \
              --kernel vmlinux -o /tftpboot/kernel

Finally, make sure that your BOOT/DCHP server is answering and that the TFTP server is active. 

Tell LinuxBIOS to boot an elf Image, and tell LinuxBIOS where it is: 

   option USE_ELF_BOOT=1

I have placed natsemi.elf in the first 64k of my BIOS flash chip, and LinuxBIOS in the second 64k. 

   insmod bios.o
   dd if=natsemi.elf of=/dev/bios bs=64k
   dd if=linuxbios.rom of=/dev/bios bs=64k seek=1

Finally boot LinuxBIOS.

How do I set GEODE graphics and video?

There is no Geode graphics support in coreboot. Install the Geode framebuffer driver for console graphics and the X driver for X support on your Geode Linux image. Current kernel and X distributions contain the required drivers. Until the driver loads there is only serial console output.

Driver source:

2.6.23 kernel framebuffer driver

X.org driver

How do I set up testbios?

Please read the testbios FAQ.

/usr/sbin/iasl: Command not found

If you see this error, you have to install iasl, Intel's ASL Optimizing Compiler:

How can I write to POSTcard port 0x80 from userspace?

This might be useful in some situations, and to output a number to a POST card:

printf "\001" | dd bs=1 seek=128 of=/dev/port

or using iotools:

iotools io_write8 0x80 0x42

In case of linux commands above do output to POST card, but the value is immediately replaced by 0x00 due to io_delay. Further explanations can be found on kernel mailinglist archive


In DOS (not Windows XP) use:

mov al, 42; out al, 80h

To output 42 type

o 80 42

in DOS debug.exe.

When using LPT (parallel port) POST card - write to port assigned to parallel port, eg. 0x3BC, 0x378, 0x278. Some SuperIOs/EmbeddedControllers will decode 0x80 like ENE KB926

Is coreboot applying x86 microcode patches?

And if yes, can they be modified?

Answer: Yes, coreboot is applying microcode patches on AMD and Intel CPUs. However, this field is little documented, so coreboot uses only unmodified, vendor-provided microcode. Few people think, that system design can seriously be improved by modifications here ( �Code patches mostly disable erraneous functions and opcodes).

How can I retrieve a good video BIOS?

Note: If you are following these instructions to build coreboot for your motherboard, this is only necessary if you have a motherboard with an embedded VGA card. If your VGA is a PCI / PCI-Express add-on card, coreboot will find and run the ROM by itself.

See VGA_support for the details.


Errors

ERROR: Not enough MTRRs available!

There are 8 dynamic MTRRs available on x86.

This message tells you that there's an error with PCI device resources.

It might be an error in the PCI handling code or the devicetree.

Can I put coreboot into a PCI expansion ROM?

Short answer: NO.

Long answer:

There's little use in doing that, as a lots of initialization has already been done by the proprietary BIOS (or coreboot) by the time the PCI expansion ROM is executed. It won't be possible to run coreboot from a PCI expansion ROM after a proprietary BIOS has already been running for instance.

Note: The Intel ICH7 southbridge seems to allows booting from PCI ROMs (not arbitrary PCI expansion ROMs as used on graphics cards, SCSI controllers, etc.) -- maybe this should be investigated in order to check if or how it might be useful.

Obsolete FAQ items

Please see FAQ/Obsolete for (probably) obsolete FAQ items.