diff options
| author | Arthur Heymans <arthur@aheymans.xyz> | 2024-02-02 19:35:13 +0100 |
|---|---|---|
| committer | Martin L Roth <gaumless@gmail.com> | 2024-03-28 15:23:21 +0000 |
| commit | d293b20b840037211d9b43ded17901354e5204ad (patch) | |
| tree | 5d2c5964d70342c6f47a6ec6ee5b34a865170681 /Documentation/arch | |
| parent | ee83be4d753ae128b53dd306b380c4a6dfd739e5 (diff) | |
cpu/x86/Kconfig: Mark 64bit support as stable
With SMM holding page tables itself, we can consider SMM support stable
and safe enough for general use.
Also update the respective documentation.
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Change-Id: Ifcf0a1a5097a2d7c064bb709ec0b09ebee13a47d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80338
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@gmail.com>
Diffstat (limited to 'Documentation/arch')
| -rw-r--r-- | Documentation/arch/x86/index.md | 13 |
1 files changed, 3 insertions, 10 deletions
diff --git a/Documentation/arch/x86/index.md b/Documentation/arch/x86/index.md index 3ddff519ea..f2597ac9ce 100644 --- a/Documentation/arch/x86/index.md +++ b/Documentation/arch/x86/index.md @@ -9,9 +9,7 @@ x86 PAE support <pae.md> ``` ## State of x86_64 support -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*. +Some SOCs now support 64bit mode. Search for HAVE_X86_64_SUPPORT in Kconfig. In order to add support for x86_64 the following assumptions were made: * The CPU supports long mode @@ -19,7 +17,6 @@ In order to add support for x86_64 the following assumptions were made: * All code that is to be run must be below 4GiB in physical memory * The high dword of pointers is always zero * The reference implementation is qemu -* The CPU supports 1GiB hugepages * x86 payloads are loaded below 4GiB in physical memory and are jumped to in *protected mode* @@ -62,7 +59,6 @@ QEMU Q35 <../../mainboard/emulation/qemu-q35.md> 1. Fine grained page tables for SMM: * Must not have execute and write permissions for the same page. * Must allow only that TSEG pages can be marked executable - * Must reside in SMRAM 2. Support 64bit PCI BARs above 4GiB 3. Place and run code above 4GiB @@ -70,13 +66,10 @@ QEMU Q35 <../../mainboard/emulation/qemu-q35.md> * Fix compilation errors * Test how well CAR works with x86_64 and paging * Improve mode switches -* Test libgfxinit / VGA Option ROMs / FSP -## Known bugs on real hardware +## Known problems on real hardware -According to Intel x86_64 mode hasn't been validated in CAR environments. -Until now it could be verified on various Intel platforms and no issues have -been found. +Running VGA rom directly fails. Yabel works fine though. ## Known bugs on KVM enabled qemu |