coreboot

coreboot supports writing POST codes to I/O port 80. There are various Kconfigs that deal with POST codes, which don’t have effect on most platforms. The code to send POST codes is scattered in C and Assembly, some use functions, some use macros and others simply use the outb instruction. The POST codes are duplicated between stages and aren’t documented properly.

Tasks¶

• Guard Kconfigs with a depends on to only show on supported platforms
• Remove duplicated Kconfigs
• Replace outb(0x80, ...) with calls to post_code(...)
• Update Documentation/POSTCODES
• Use defines from console/post_codes.h where possible
• Drop duplicated POST codes
• Make use of all possible 255 values

Requirements¶

• Knowledge in the coreboot build system and the concept of stages
• Other knowledge: Little experience with C and x86 Assembly
• Hardware requirements: Nothing special

Mentors¶

• Patrick Rudolph patrick.rudolph@9elements.com
• Christian Walter christian.walter@9elements.com