Good day!
I'm one of the
coreboot users/developers. This is FOSS alternative to legacy BIOS/EFI. It let boot any elf image, or SeaBIOS (which provide legacy bios services).
And it's pretty small. So, as usually modern BIOS flash chips are big, you can place your tiny own OS in ROM.
As example, i'm working on booting KolibriOS from
coreboot. Now it booting oveer SeaBIOS, but i'm hope exclude SeaBIOS stage from booting.
First of all - please, read our wiki
http://www.coreboot.org/Found supported hardware
http://www.coreboot.org/Supported_Motherboardsand decide which you have to try
coreboot, or you can use QEMU.
1. Download&configure&build:
Code:
svn co svn://coreboot.org/coreboot/trunk coreboot
cd coreboot
make menuconfig
You need to choose targets->QEMU for producing image for qemu. Then run
Code:
make
2. Output will be in
coreboot.rom inside build directory.
3. Download vgabios image for qemu from
http://www.coreboot.org/images/0/0d/Vgabios-cirrus.zip4. You need latest qemu (0.14 or from git)
3. Copy
coreboot.rom in working directory, rename it into bios.bin
Copy vgabios-cirrus.bin here also.
4. Run qemu with
Code:
qemu -L . -cdrom kolibri.iso -serial stdio
where kolibri.iso is kolibrios image, but can be your own OS image. "-L ." option point qemu to directory where bios.bin and vgabios-cirrus.bin files.
here is my example image:
Code:
coreboot.rom: 4096 kB, bootblocksize 1504, romsize 4194304, offset 0x0
Alignment: 64 bytes
Name Offset Type Size
cmos_layout.bin 0x0 unknown 1159
fallback/romstage 0x4c0 stage 12720
fallback/coreboot_ram 0x36c0 stage 27797
fallback/payload 0xa3c0 payload 40596
(empty) 0x142c0 null 4110104
Also you can pack OS image in rom:
I'm using kolibri.img (floppy image):
Code:
lzma -zc kolibri.img > kolibri.img.lzma
./build/cbfstool coreboot.rom add kolibri.img.lzma floppyimg/Kolibri.lzma raw
where cbfstool in build directory of
coreboot tree.
you can check now result with:
Code:
./build/cbfstool coreboot.rom print
Now you can also rename
coreboot.rom into bios.bin for your working directory and try boot with qemu.
Also,
coreboot let you boot:
For additional info, please read first:
http://www.coreboot.org/FAQ- http://www.coreboot.org/Developer_Manual
- http://www.coreboot.org/Payloads
- http://www.coreboot.org/SeaBIOS
- http://www.coreboot.org/FILO
- http://www.coreboot.org/Libpayload
- http://www.coreboot.org/Payload_API
For flashing your image you can use flashrom utility (
http://www.flashrom.org) - please always use latest (from svn) version!!!
For debugging this on real hardware you can use SerialICE
http://www.serialice.com/I'm attaching ready image and some files from libpayload to show how-to work with
coreboot specifics
Here is configs + images
http://rghost.net/5482306