Patrick Rudolph has submitted this change. ( https://review.coreboot.org/c/coreboot/+/29667 )
Change subject: mb/emulation/qemu-q35,qemu-i440fx: Add x86_64 support ......................................................................
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 siro@das-labor.org Reviewed-on: https://review.coreboot.org/c/coreboot/+/29667 Reviewed-by: Arthur Heymans arthur@aheymans.xyz Tested-by: build bot (Jenkins) no-reply@coreboot.org --- M Documentation/arch/x86/index.md A Documentation/mainboard/emulation/qemu-i440fx.md A Documentation/mainboard/emulation/qemu-q35.md M Documentation/mainboard/index.md M src/cpu/qemu-x86/Kconfig 5 files changed, 165 insertions(+), 19 deletions(-)
Approvals: build bot (Jenkins): Verified Arthur Heymans: Looks good to me, approved
diff --git a/Documentation/arch/x86/index.md b/Documentation/arch/x86/index.md index 7b9e1fc..11d8a4f 100644 --- a/Documentation/arch/x86/index.md +++ b/Documentation/arch/x86/index.md @@ -5,10 +5,11 @@ * [x86 PAE support](pae.md)
## State of x86_64 support -At the moment there's no single board that supports x86_64 or to be exact -`ARCH_RAMSTAGE_X86_64` and `ARCH_ROMSTAGE_X86_64`. +At the moment there's only experimental x86_64 support. +The `emulation/qemu-i440fx` and `emulation/qemu-q35` boards do support +*ARCH_RAMSTAGE_X86_64* , *ARCH_POSTCAR_X86_64* and *ARCH_ROMSTAGE_X86_64*.
-In order to add support for x86_64 the following assumptions are made: +In order to add support for x86_64 the following assumptions were made: * The CPU supports long mode * All memory returned by malloc must be below 4GiB in physical memory * All code that is to be run must be below 4GiB in physical memory @@ -39,18 +40,16 @@
At the moment *$n* is 4, which results in identity mapping the lower 4 GiB.
-## Steps to add basic support for x86_64 -* Add x86_64 toolchain support - *DONE* -* Fix compilation errors - *DONE* -* Fix linker errors - *TODO* -* Add x86_64 rmodule support - *DONE* -* Add x86_64 exception handlers - *DONE* -* Setup page tables for long mode - *DONE* -* Add assembly code for long mode - *DONE* -* Add assembly code for SMM - *DONE* -* Add assembly code for postcar stage - *DONE* -* Add assembly code to return to protected mode - *DONE* -* Implement reference code for mainboard `emulation/qemu-q35` - *TODO* +## Basic x86_64 support +Basic support for x86_64 has been implemented for QEMU mainboard target. + +## Reference implementation +The reference implementation is +* [QEMU i440fx](../../mainboard/emulation/qemu-i440fx.md) +* [QEMU Q35](../../mainboard/emulation/qemu-q35.md) + +## TODO +* Identity map memory above 4GiB in ramstage
## Future work
diff --git a/Documentation/mainboard/emulation/qemu-i440fx.md b/Documentation/mainboard/emulation/qemu-i440fx.md new file mode 100644 index 0000000..059ad12 --- /dev/null +++ b/Documentation/mainboard/emulation/qemu-i440fx.md @@ -0,0 +1,64 @@ +# qemu i440fx mainboard + +## Running coreboot in qemu +Emulators like qemu don't need a firmware to do hardware init. +The hardware starts in the configured state already. + +The coreboot port allows to test non mainboard specific code. +As you can easily attach a debugger, it's a good target for +experimental code. + +## coreboot x86_64 support +coreboot historically runs in 32-bit protected mode, even though the +processor supports x86_64 instructions (long mode). + +The qemu-i440fx mainboard has been ported to x86_64 and will serve as +reference platform to enable additional platforms. + +To enable the support set the Kconfig option ``CONFIG_CPU_QEMU_X86_64=y``. + +## Installing qemu + +On debian you can install qemu by running: +```bash +$ 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 +``` diff --git a/Documentation/mainboard/emulation/qemu-q35.md b/Documentation/mainboard/emulation/qemu-q35.md new file mode 100644 index 0000000..00163e8 --- /dev/null +++ b/Documentation/mainboard/emulation/qemu-q35.md @@ -0,0 +1,64 @@ +# 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_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 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. + +```bash +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: + +```bash +qemu-system-x86_64 -bios build/coreboot.rom -serial stdio -M q35 -accel kvm -cpu host +``` + diff --git a/Documentation/mainboard/index.md b/Documentation/mainboard/index.md index 1749064..0eefee8 100644 --- a/Documentation/mainboard/index.md +++ b/Documentation/mainboard/index.md @@ -37,6 +37,8 @@ - [Spike RISC-V emulator](emulation/spike-riscv.md) - [Qemu RISC-V emulator](emulation/qemu-riscv.md) - [Qemu AArch64 emulator](emulation/qemu-aarch64.md) +- [Qemu x86 Q35](emulation/qemu-q35.md) +- [Qemu x86 PC](emulation/qemu-i440fx.md)
diff --git a/src/cpu/qemu-x86/Kconfig b/src/cpu/qemu-x86/Kconfig index 21ada02..af0c746 100644 --- a/src/cpu/qemu-x86/Kconfig +++ b/src/cpu/qemu-x86/Kconfig @@ -2,12 +2,29 @@
config CPU_QEMU_X86 bool - select ARCH_BOOTBLOCK_X86_32 - select ARCH_VERSTAGE_X86_32 - select ARCH_ROMSTAGE_X86_32 - select ARCH_RAMSTAGE_X86_32 select SMP select UDELAY_TSC select TSC_MONOTONIC_TIMER select UNKNOWN_TSC_RATE select SMM_ASEG + +if CPU_QEMU_X86 + +config CPU_QEMU_X86_64 + bool "Experimental 64bit support" + select ARCH_BOOTBLOCK_X86_64 + select ARCH_VERSTAGE_X86_64 + select ARCH_ROMSTAGE_X86_64 + select ARCH_POSTCAR_X86_64 + select ARCH_RAMSTAGE_X86_64 + +config CPU_QEMU_X86_32 + bool + default n if CPU_QEMU_X86_64 + default y + select ARCH_BOOTBLOCK_X86_32 + select ARCH_VERSTAGE_X86_32 + select ARCH_ROMSTAGE_X86_32 + select ARCH_POSTCAR_X86_32 + select ARCH_RAMSTAGE_X86_32 +endif
-
Patrick Rudolph (Code Review)