Difference between revisions of "Board:tyan/s2892"

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Line 1: Line 1:
 
== Purpose ==
 
== Purpose ==
Customize the system to allow me to play with memory mappings and large
+
Customize the system to allow me to play with memory mappings and large devices.  I wanted to minimize intermediate steps from LinuxBIOS to Linux to minimize the areas of expertise I needed to develop. I also wanted to be able to use the SATA drives as my boot drives.
devices.  I wanted to minimize intermediate steps from LinuxBIOS to Linux to
+
minimize the areas of expertise I needed to develop. I also wanted to be
+
able to use the SATA drives as my boot drives.
+
  
 
==Disclaimer ==
 
==Disclaimer ==
Line 16: Line 13:
 
== The procedure ==
 
== The procedure ==
  
I started by installing LinuxBIOS on the system and using FILO and Etherboot
+
I started by installing LinuxBIOS on the system and using FILO and Etherboot to boot to a kernel.  This allowed me to try the different payloads without flashing every time.
to boot to a kernel.  This allowed me to try the different payloads without
+
flashing every time.
+
  
 
Next I downloaded the OLPC buildrom
 
Next I downloaded the OLPC buildrom
Line 24: Line 19:
 
  git clone git://dev.laptop.org/users/jcrouse/buildrom
 
  git clone git://dev.laptop.org/users/jcrouse/buildrom
  
I built it on my 32-bit system for convenience building the kernel.
+
I modified the Config.mk to include pciutils from
  
I modified the Config.mk to include pciutils from http://buildroot.uclibc.org/cgi-bin/viewcvs.cgi/trunk/buildroot/package/
+
http://buildroot.uclibc.org/cgi-bin/viewcvs.cgi/trunk/buildroot/package/
  
 
and took out the graphical boot menu.  I also modified
 
and took out the graphical boot menu.  I also modified
 
''buildrom/skeleton/devices.txt'' to add lines for my hard drives.  I just
 
''buildrom/skeleton/devices.txt'' to add lines for my hard drives.  I just
copied the lines for ''sda'' and ''sda1'' and made ''hda hda1 hda2'' and ''sda2''.  The
+
copied the lines for ''sda'' and ''sda1'' and made ''hda hda1 hda2'' and ''sda2''.  The important thing is to make sure that the major and minor numbers are correct.
important thing is to make sure that the major and minor numbers are
+
correct.
+
  
I modified ''buildrom/skeleton/linuxrc'' so that the device files were created
+
I modified ''buildrom/skeleton/linuxrc'' so that the device files were created earlier, ''/dev/null'' didn't become a text file, and my drives got mounted in read-only mode.
earlier, ''/dev/null'' didn't become a text file, and my drives got mounted.
+
  
I then modified buildrom/skeleton/bin/boot.functions so that ''doboot()'' called
+
I then modified buildrom/skeleton/bin/boot.functions so that ''doboot()'' called my script on the hard drive for the kexec.  That's nice to avoid flashing the BIOS for booting different kernels.
my script on the hard drive for the kexec.  That's nice to avoid flashing
+
the BIOS for booting different kernels.
+
  
 
I downloaded Linux 2.6.18.1 (2.6.18-rc4 had some problems with SATA) and
 
I downloaded Linux 2.6.18.1 (2.6.18-rc4 had some problems with SATA) and
Line 45: Line 35:
 
''12-tiny-tiny-crc.patch'' fails, but was easy to apply by hand.
 
''12-tiny-tiny-crc.patch'' fails, but was easy to apply by hand.
  
I configured the kernel to include support for ext2 and ext3, SATA, and IDE.
+
I configured the kernel to include support for ext2, SATA, and IDE.
  
I ran make and copied the payloads from the ''buildrom/deploy'' directory to my
+
I ran make and copied the payloads from the ''buildrom/deploy'' directory to my s2892 to be used. ''olpc-payload.elf.lzma'' (732K) is used for booting directly from LinuxBIOS, and ''olpc-payload-uncompressed.elf'' (1.7M) was useful for testing it with FILO and Etherboot.
s2892 to be used. ''olpc-payload.elf.lzma'' (732K) is used for booting directly
+
from LinuxBIOS, and ''olpc-payload-uncompressed.elf'' (1.7M) was useful for
+
testing it with FILO and Etherboot.
+
  
I'd like to go one step further and use a 64-bit kernel so that any changes
+
mkelfImage wouldn't work with the vmlinux file, so I changed the Makefile to get it to use the bzImage instead.
I make to the kernel only need to be made once. Looking at mkelfimage, it
+
looks like the 64-bit file format is not supported.  It might be a simple
+
change, but I don't know how to do it.
+
 
+
Since I couldn't figure out how to make LinuxBIOS do without the Fallback
+
image, I configured it to have a zero size payload.
+
  
 
Now I have
 
Now I have
* normal/linuxbios.strip (128K)
+
* fallback/linuxbios.strip (88K)
* fallback/linuxbios.strip (128K)
+
* normal/payload (860K)
* normal/payload (732K)
+
* fallback/payload (0K)
+
 
* s2892vBIOS.bin (36K)
 
* s2892vBIOS.bin (36K)
  
If I could get rid of the fallback it would make room for the 64-bit kernel
+
WARNING: I have a bios savior so that when I mess up I can get my machine backIf you don't have one, you might not want to do the fallback only boot.
(50K bigger than the 32-bit kernel)Then I'd just need to modify
+
mkelfimage and I'd be almost there :) I guess I could take out pciutils to
+
make up most of the difference (44K), but I like having them there for
+
debug.
+
  
  
Config.lb:
+
 
----------------------
+
== Config.lb ==
  
 
  # Sample config file for
 
  # Sample config file for
Line 84: Line 59:
 
  mainboard tyan/s2892
 
  mainboard tyan/s2892
 
   
 
   
  option ROM_SIZE      =0xf7000
+
  option ROM_SIZE      = 0xf7000 # 8Mbit - 36K for VGA BIOS
 
   
 
   
 
  option CONFIG_ROM_STREAM=1
 
  option CONFIG_ROM_STREAM=1
 
   
 
   
  option CONFIG_CONSOLE_SERIAL8250=1
+
  option CONFIG_CONSOLE_SERIAL8250 = 1
  option CONFIG_CONSOLE_VGA=1
+
  option CONFIG_CONSOLE_VGA = 1
  option FALLBACK_SIZE =0x20000
+
  option FALLBACK_SIZE = ROM_SIZE
  option ROM_IMAGE_SIZE=0x20000
+
  option ROM_IMAGE_SIZE = 0x16000
 
   
 
   
 
  # Tyan s2892
 
  # Tyan s2892
  romimage "normal"
+
  romimage "fallback"
 
         option CONFIG_COMPRESSED_ROM_STREAM_LZMA=1
 
         option CONFIG_COMPRESSED_ROM_STREAM_LZMA=1
 
         option CONFIG_PRECOMPRESSED_ROM_STREAM=1
 
         option CONFIG_PRECOMPRESSED_ROM_STREAM=1
        option USE_FALLBACK_IMAGE=0
 
        option LINUXBIOS_EXTRA_VERSION="$(shell cat ../../VERSION)_Normal"
 
        payload ../olpc-payload.elf.lzma
 
end
 
 
romimage "fallback"
 
        option CONFIG_COMPRESSED_ROM_STREAM_LZMA=0
 
        option CONFIG_PRECOMPRESSED_ROM_STREAM=0
 
 
         option USE_FALLBACK_IMAGE=1
 
         option USE_FALLBACK_IMAGE=1
 
         option LINUXBIOS_EXTRA_VERSION="$(shell cat ../../VERSION)_Fallback"
 
         option LINUXBIOS_EXTRA_VERSION="$(shell cat ../../VERSION)_Fallback"
         payload ../payload.zero
+
         payload ../olpc-payload.elf.lzma
 
  end
 
  end
  buildrom ./linuxbios.rom ROM_SIZE "normal" "fallback"
+
 +
  buildrom ./linuxbios.rom ROM_SIZE "fallback"
 +
 
 +
 
 +
== Kexec-tools ==
 +
 
 +
Because the kexec tools that are included with OLPC's buildrom are stripped down for 32-bit kernels, I built kexec statically linked (read "large file") and put it on the hard drive with the kernel to be loaded.  I use kexec to boot my kernel which has been combined with initrd into an elf with mkelfImage:
 +
 
 +
mkelfImage --comand--line="ro root=/dev/hda1 console=tty0" --kernel="" --initrd="" --output="mylinux.elf"
 +
 
 +
I have to use
 +
kexec -f mylinux.elf
 +
because otherwise kexec calls shutdown and there is no shutdown in the OLPC initrd.  I guess that's a half truth, because when I call kexec without the -f it reboots the machine completely instead of a kexec when shutdown is available.
 +
 
 +
== Status ==
 +
My machine boots LinuxBIOS, then linux-2.6.18.1-tiny, then kexecs into linux-2.6.18.1-normal.  It takes a little longer than going through elfboot and FILO, but it is a simpler path.
  
 
== Author ==
 
== Author ==
  
 
This document was written by Myles Watson <myles at pel dot cs dot byu dot edu>
 
This document was written by Myles Watson <myles at pel dot cs dot byu dot edu>

Revision as of 21:23, 26 October 2006

Purpose

Customize the system to allow me to play with memory mappings and large devices. I wanted to minimize intermediate steps from LinuxBIOS to Linux to minimize the areas of expertise I needed to develop. I also wanted to be able to use the SATA drives as my boot drives.

Disclaimer

There are several places where my solutions are not as elegant as I wished them to be. Suggestions are welcome.

Current set up

  • Tyan s2892
  • LinuxBIOS with Linux 2.6.18-tiny as a payload

The procedure

I started by installing LinuxBIOS on the system and using FILO and Etherboot to boot to a kernel. This allowed me to try the different payloads without flashing every time.

Next I downloaded the OLPC buildrom

git clone git://dev.laptop.org/users/jcrouse/buildrom

I modified the Config.mk to include pciutils from

http://buildroot.uclibc.org/cgi-bin/viewcvs.cgi/trunk/buildroot/package/

and took out the graphical boot menu. I also modified buildrom/skeleton/devices.txt to add lines for my hard drives. I just copied the lines for sda and sda1 and made hda hda1 hda2 and sda2. The important thing is to make sure that the major and minor numbers are correct.

I modified buildrom/skeleton/linuxrc so that the device files were created earlier, /dev/null didn't become a text file, and my drives got mounted in read-only mode.

I then modified buildrom/skeleton/bin/boot.functions so that doboot() called my script on the hard drive for the kexec. That's nice to avoid flashing the BIOS for booting different kernels.

I downloaded Linux 2.6.18.1 (2.6.18-rc4 had some problems with SATA) and patched it with the tiny patches that came with OLPC. 12-tiny-tiny-crc.patch fails, but was easy to apply by hand.

I configured the kernel to include support for ext2, SATA, and IDE.

I ran make and copied the payloads from the buildrom/deploy directory to my s2892 to be used. olpc-payload.elf.lzma (732K) is used for booting directly from LinuxBIOS, and olpc-payload-uncompressed.elf (1.7M) was useful for testing it with FILO and Etherboot.

mkelfImage wouldn't work with the vmlinux file, so I changed the Makefile to get it to use the bzImage instead.

Now I have

  • fallback/linuxbios.strip (88K)
  • normal/payload (860K)
  • s2892vBIOS.bin (36K)

WARNING: I have a bios savior so that when I mess up I can get my machine back. If you don't have one, you might not want to do the fallback only boot.


Config.lb

# Sample config file for
# the Tyan s2892
# This will make a target directory of ./s2892

target s2892
mainboard tyan/s2892

option ROM_SIZE      = 0xf7000 # 8Mbit - 36K for VGA BIOS

option CONFIG_ROM_STREAM=1

option CONFIG_CONSOLE_SERIAL8250 = 1
option CONFIG_CONSOLE_VGA = 1
option FALLBACK_SIZE = ROM_SIZE
option ROM_IMAGE_SIZE = 0x16000

# Tyan s2892
romimage "fallback"
        option CONFIG_COMPRESSED_ROM_STREAM_LZMA=1
        option CONFIG_PRECOMPRESSED_ROM_STREAM=1
        option USE_FALLBACK_IMAGE=1
        option LINUXBIOS_EXTRA_VERSION="$(shell cat ../../VERSION)_Fallback"
        payload ../olpc-payload.elf.lzma
end

buildrom ./linuxbios.rom ROM_SIZE "fallback"


Kexec-tools

Because the kexec tools that are included with OLPC's buildrom are stripped down for 32-bit kernels, I built kexec statically linked (read "large file") and put it on the hard drive with the kernel to be loaded. I use kexec to boot my kernel which has been combined with initrd into an elf with mkelfImage:

mkelfImage --comand--line="ro root=/dev/hda1 console=tty0" --kernel="" --initrd="" --output="mylinux.elf"

I have to use

kexec -f mylinux.elf 

because otherwise kexec calls shutdown and there is no shutdown in the OLPC initrd. I guess that's a half truth, because when I call kexec without the -f it reboots the machine completely instead of a kexec when shutdown is available.

Status

My machine boots LinuxBIOS, then linux-2.6.18.1-tiny, then kexecs into linux-2.6.18.1-normal. It takes a little longer than going through elfboot and FILO, but it is a simpler path.

Author

This document was written by Myles Watson <myles at pel dot cs dot byu dot edu>