Wanna play coreboot but have no supported physical motherboard? Don’t worry! AMD SimNow can help you out!
The official website of coreboot has a tutorial for using AMD SimNow, but it’s kind of brief stuff, i’ll try to demo here step by step, in windows OS.
Run coreboot on AMD SimNow virtual platform in Windows OS environment.
I’m use windows OS for this test, so environment as below:
- OS: Windows8.1 x64, SimNow not works for 32bit
- AMD SimNow v4.6.2 for windows: ->download
- Coreboot v4
- Coreboot windows build environment: win-build-env-015.7z
please notice that the win-build-env included coreboot v4 source code, but it may not be latest one, you can update it by
git pull, but i got some build error when use default code, so i
git clone http://review.coreboot.org/p/coreboot and replace this win-build-env coreboot version.
Choose SimNow Platform Configuration
After Check AMD developer knowledge base, SimNow supports platforms with coreboot lists as below:
cheetah_*.bsd, but it takes a long time to boot due to ECC memory supported. So i suggest to use
Family10_1p.bsd, after open this bsd by
File->Open BSD in SimNow, you can check devices in menu
- AMD-8132 PCI-X controller
- AMD-8111 I/O hub
- Winbond W83627HF SIO
Choose Coreboot Mainboard
Which coreboot mainboard support SimNow Family10_1p.bsd? let’s try
You can found in Kconfig that it supports below list, should works for our chosen Family10_1p board.
select NORTHBRIDGE_AMD_AMDFAM10 select SOUTHBRIDGE_AMD_AMD8111 select SOUTHBRIDGE_AMD_AMD8132 select SUPERIO_WINBOND_W83627HF
You may found that SimNow system no display without this step, due to lack of onboard VBIOS binary. if you tried some unsupported VBIOS, you may get below error. check coreboot VGA_Support website if there’s a way to get supported VBIOS.
CBFS: WARNING: 'pci1022,2067.rom' not found. CBFS: Could not find file 'pci1022,2067.rom'. Option ROM execution disabled for PCI: 01:04.0
Luckily, AMD SimNow provided a simulated PCI VGA called Emerald Graphic Deivce. Do remember to enable options in coreboot to run VGA option ROMs, coreboot default enable run VGA option roms, so you can leave it as default when setting .config, but if no display, you will need to check these options.
Chipset ---> [*] Setup bridges on path to VGA adapter [*] Run VGA option ROMs Option ROM execution type (Native mode) --->
Build Coreboot ROM for SimNow
please refer to this website for the step-by-step instructions for building a coreboot BIOS in a windows machine.
my steps as below:
*1. run go.bat, enter Msys2 coreboot build environment
*2. setting coreboot options by
$ make oldconfig
my configuration as below, others use default settings:
- select mainboard vendor AMD
* * Mainboard * Mainboard vendor 5. AMD (VENDOR_AMD) (NEW)
- choose mainboard ‘Serengeti Cheetah (Fam10)’
Mainboard model 10. Serengeti Cheetah (Fam10) (BOARD_AMD_SERENGETI_CHEETAH_FAM10) (NEW)
- choose seabios as a payload, you can also try other payloads, such as FILO which is introduced by the tutorial, but i can not build FILO successful. If you already have a payload ELF, you can select 2 and give the ELF file path.
* * Payload * Add a payload 2. An ELF executable payload (PAYLOAD_ELF) (NEW) 4. SeaBIOS (PAYLOAD_SEABIOS) (NEW) 5. FILO (PAYLOAD_FILO) (NEW)
the configuration will be written to
*3. build out coreboot.rom by
if build success, you can check rom information as below, and coreboot.rom will be in
coreboot.rom: 1024 kB, bootblocksize 2544, romsize 1048576, offset 0x0 alignment: 64 bytes, architecture: x86 Name Offset Type Size cmos_layout.bin 0x0 cmos_layout 1776 fallback/romstage 0x740 stage 75709 fallback/ramstage 0x12f40 stage 70619 fallback/payload 0x24380 payload 56085 config 0x31f00 raw 4321 revision 0x33040 raw 700 (empty) 0x33340 null 836184 HOSTCC cbfstool/rmodtool.o HOSTCC cbfstool/rmodule.o HOSTCC cbfstool/rmodtool (link)
Running Coreboot on SimNow
*1. run simnow.exe, and open Family10h_1p.bsd by
$ cp build/coreboot.rom /c/SimNow/images/
*3. Open SimNow Device Window by
Double click the
Memory Device to change bios rom to coreboot, change base address to
fff00000 and size to
32 for 1MB BIOS ROM. notice that if you don’t change base address, you will not able to change size.
(Optional)Double click the
AMD 8111 I/O Hub to add CD-ROM boot image, a windows XP CD-ROM in my case.
*4. Execute following commmands on ‘simnow>’ promt to open com port debug, coreboot will throw out debug messages, and then you can get these messages by Putty.exe in windows.
1 simnow> serial.SetCommPort pipe
*5. Start the SimNow simulator by click the `Run Simulation’ button on main window
*6. Run Putty.exe in a new command prompt to capture debug messages, please notice that you must run simulation before this step, or putty will unable to open serial port. command as below, you can make a bat file for this command.
start putty -serial \\.\pipe\SimNow.Com1
*7. After a few seconds, run emerald graphic VBIOS and video will appear, notice that
Diagnostic Ports will show debug numbers on 80 port.
*8. Boot to load Seabios payload, and try to boot CD/DVD.
*9. Opps! windows BSOD… need some ACPI debugging or disable ACPI support here.
Add EDK2 Duet Payload
Wanna support UEFI? Let’s add EDK2 payload for coreboot. Please refer to notabs.org EDK2 Duet payload for coreboot.
After download the duetpayload package, you can find built out UEFI payload in this folder:
If you want to build this payload, please follow the steps descripted in this page of notabs.org.
You can NOT just add it as a ELF payload file when build coreboot, so:
1. Build coreboot with
2. Run cbfstool to add EFILDR16 as a payload to coreboot.rom binary
build/cbfstool build/coreboot.rom add-flat-binary -f ../edk2/build/images/EFILDR16 -n fallback/payload -l 0x100000 -e 0x102000
this UEFI payload size is about 918KB i can’t even add it into a 1MB size coreboot rom, so i increase the coreboot rom size to 2MB, and change the rom size of AMD SimNow to verify this payload.
How to change size of coreboot.rom?
the build out rom size is 1MB in this example, you can change to 512KB when setting .config.
ROM Chip Size 4. 512 KB (COREBOOT_ROMSIZE_KB_512) (NEW)
How to re-config coreboot settings?
If you want to change some settings in .config file, just re-run
make oldconfig will not work, you can modify settings in .config, then run
make clean before
make oldconfig. But if you delete the
.config.old files, you have to re-config all settings.
.config sample file
my .config content
Coreboot post log
my putty log