Debugging coreboot in qemu environment - part 1

First of all I use testing version of Debian - wheezy. Clone coreboot repository:

git clone http://review.coreboot.org/p/coreboot

Conifigure:

cd coreboot; make menuconfig

Set:

Payload  ---> Add a payload ---> FILO
Payload  ---> FILO version ---> HEAD
Debugging  ---> Check PIRQ table consistency
Debugging  ---> Output verbose malloc debug messages
Debugging  ---> Output verbose ACPI debug messages
Debugging  ---> Enable debug messages for option ROM execution
Debugging  ---> Built-in low-level shell
Debugging  ---> Trace function calls

Try to build:

make

If everything builds correctly you can process. Sometimes there is need to use cross compiler. To build one:

cd util/crossgcc

./buildgcc

To explore coreboot code effectively I suggest to create tags and cscope database for coreboot. In my personal workspace I've got process that I go through before I start work (if you use my workspace configuration which is available @github you can follow below steps directly, if not adjust to your enviroment):

1. run vim ;)
2. :cd /path/to/code
3. s<Tab> (fuzzyfinder -> bookmark dir)
4. si (fuzzyfinder -> change dir)
5. sr (run ctags to generate tags and cscope to build symbol database - ctags -R;cscope -R -q -b -v)

After steps above we can start work with code. Run vim in coreboot dirctory. Type:
:e src/cpu/x86/16bit/reset16.inc
Put cursor over protected_start and press Ctrl-]. If everything goes ok you should jump to build/mainboard/emulation/qemu-x86/bootblock.s line 537.


In second article we dive into first phase of coreboot execution in emulated environment.