From 57907fcebf12961a0dbd7300472a83711d251375 Mon Sep 17 00:00:00 2001 From: Patrick Rudolph Date: Thu, 15 Nov 2018 13:42:15 +0100 Subject: mb/emulation/qemu-q35,qemu-i440fx: Add x86_64 support * Enable optional x86_64 romstage, postcar and ramstage * Add Kconfig for x86_64 compilation * Add documentation for x86 qemu mainboards * Increase CAR stack as x86_64 uses more than 0x4000 bytes Working: * Boots to Linux * Boots to SeaBIOS * Drops to protected mode at end of ramstage * Enumerates PCI devices * Relocateable ramstage * SMM Change-Id: If2f02a95b2f91ab51043d4e81054354f4a6eb5d5 Signed-off-by: Patrick Rudolph Reviewed-on: https://review.coreboot.org/c/coreboot/+/29667 Reviewed-by: Arthur Heymans Tested-by: build bot (Jenkins) --- Documentation/mainboard/emulation/qemu-i440fx.md | 64 ++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 Documentation/mainboard/emulation/qemu-i440fx.md (limited to 'Documentation/mainboard/emulation/qemu-i440fx.md') diff --git a/Documentation/mainboard/emulation/qemu-i440fx.md b/Documentation/mainboard/emulation/qemu-i440fx.md new file mode 100644 index 0000000000..059ad123c5 --- /dev/null +++ b/Documentation/mainboard/emulation/qemu-i440fx.md @@ -0,0 +1,64 @@ +# qemu i440fx 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-i440fx 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_CPU_QEMU_X86_64=y``. + +## Installing qemu + +On debian you can install qemu by running: +```bash +$ sudo apt-get install qemu +``` + +On redhat you can install qemu by running: +```bash +$ 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. + +```bash +qemu-system-i386 -bios build/coreboot.rom -serial stdio -M pc +``` + +### 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, +as well as firmware. + +```bash +qemu-system-x86_64 -bios build/coreboot.rom -serial stdio -M pc +``` + +## 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: + +```bash +qemu-system-x86_64 -bios build/coreboot.rom -serial stdio -M pc -accel kvm -cpu host +``` -- cgit v1.2.3