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Diffstat (limited to 'Documentation/arch/x86')
| -rw-r--r-- | Documentation/arch/x86/index.md | 29 |
1 files changed, 14 insertions, 15 deletions
diff --git a/Documentation/arch/x86/index.md b/Documentation/arch/x86/index.md index 7b9e1fcfa011..11d8a4f77bb9 100644 --- a/Documentation/arch/x86/index.md +++ b/Documentation/arch/x86/index.md @@ -5,10 +5,11 @@ This section contains documentation about coreboot on x86 architecture. * [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 @@ The page tables contains the following structure: 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 |