16fe5e1511
Introduce `USE_EXP_X86_64_SUPPORT` in `src/arch/x86/Kconfig` and guard it with `HAVE_EXP_X86_64_SUPPORT`. Replace the per-CPU implementations of the same functionality with the newly-added Kconfig options. Update documentation and the config file for QEMU accordingly. Change-Id: I550216fd2a8323342d6b605306b0b95ffd5dcd1c Signed-off-by: Angel Pons <th3fanbus@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/55760 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Patrick Rudolph <siro@das-labor.org>
1.7 KiB
qemu q35 mainboard
Running coreboot in qemu
Emulators like qemu don't need a firmware to do hardware init. The hardware starts in the configured state already.
The coreboot port allows to test non mainboard specific code. As you can easily attach a debugger, it's a good target for experimental code.
coreboot x86_64 support
coreboot historically runs in 32-bit protected mode, even though the processor supports x86_64 instructions (long mode).
The qemu-q35 mainboard has been ported to x86_64 and will serve as reference platform to enable additional platforms.
To enable the support set the Kconfig option CONFIG_USE_EXP_X86_64_SUPPORT=y.
Installing qemu
On debian you can install qemu by running:
$ sudo apt-get install qemu
On redhat you can install qemu by running:
$ sudo dnf install qemu
Running coreboot
To run the i386 version of coreboot (default)
Running on qemu-system-i386 will require a 32 bit operating system.
qemu-system-i386 -bios build/coreboot.rom -serial stdio -M q35
To run the experimental x86_64 version of coreboot
Running on qemu-system-x86_64 allows to run a 32 bit or 64 bit operating system
and firmware.
qemu-system-x86_64 -bios build/coreboot.rom -serial stdio -M q35
Finding bugs
To test coreboot's x86 code it's recommended to run on a x86 host and enable KVM. It will not only run faster, but is closer to real hardware. If you see the following message:
KVM internal error. Suberror: 1
emulation failure
something went wrong. The same bug will likely cause a FAULT on real hardware, too.
To enable KVM run:
qemu-system-x86_64 -bios build/coreboot.rom -serial stdio -M q35 -accel kvm -cpu host