User talk:MrNuke: Difference between revisions

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== Ideas for generic handling of devices ==
== Sections deserving their own page ==
 
* [[User_talk:MrNuke/Block_Device_API]]
IMPORTANT! Feel free to edit this page to share your thoughts and ideas. This is the official MMC open brainstorming page.
 
=== Proposal 1: Unified API ===
Chan is an IO channel.
 
This struct is used in Inferno and has been for a long time; so it works.
It's also in the opcodes somewhat like what we did for EMMC on ARM.
 
struct Dev
{
char* name;
void (*reset)(void);
void (*init)(void);
void (*shutdown)(void);
Chan* (*attach)(char*); /* tell the device you want to use it */
Walkqid* (*walk)(Chan*, Chan*, char**, int); /* walk to a name in the device's managed name space; return a handle */
int (*stat)(Chan*, uchar*, int); // status info
Chan* (*open)(Chan*, int); /* get access to a resource in the device name space */
void (*close)(Chan*); /* tell it you are done with whatever it is. */
long (*read)(Chan*, void*, long, vlong);
long (*write)(Chan*, void*, long, vlong);
void (*power)(int); /* power mgt: power(1) ? on, power (0) ? off */
};
 
==== Questions ====
 
# Do we want to expose or hide the block nature of some devces (i.e. force reading multiples of blocksize, or allow reading any number of bytes, with no alignment requirement) ?
# How do we connect the dots, such that most of the details can be handled transparently ?
# How simple or complex do we want the API to be such that it can work in any stage (including bootblock, assuming some SRAM and a stack are available) ?
# Can we integrate this into '''libpayload''' such that the same sources can be used for both coreboot and libpayload ?
#* think "Device specfic storage drivers -> [*] Allwinner A10 MMC driver" in '''libpayload''' config
# More questions coming soon (TM)

Revision as of 18:05, 6 February 2014

Sections deserving their own page