"Huang, Ying" <[EMAIL PROTECTED]> writes: > On Mon, 2007-07-30 at 22:40 -0600, Eric W. Biederman wrote: >> "Huang, Ying" <[EMAIL PROTECTED]> writes: >> >> > This patch adds document for EFI x86_64 support. The boot parameters >> > added are documented in Documentation/i386/zero-page.txt. The setup >> > and operation guide of EFI based system is documented in >> > Documentation/x86_64/uefi.txt. >> > >> > Signed-off-by: Chandramouli Narayanan <[EMAIL PROTECTED]> >> > Signed-off-by: Huang Ying <[EMAIL PROTECTED]> >> > >> > --- >> > >> > i386/zero-page.txt | 18 ++++++++++++++---- >> > x86_64/uefi.txt | 42 ++++++++++++++++++++++++++++++++++++++++++ >> > 2 files changed, 56 insertions(+), 4 deletions(-) >> > >> > Index: linux-2.6.23-rc1/Documentation/i386/zero-page.txt >> > =================================================================== >> > --- linux-2.6.23-rc1.orig/Documentation/i386/zero-page.txt 2007-07-30 >> > 11:28:45.000000000 +0800 >> > +++ linux-2.6.23-rc1/Documentation/i386/zero-page.txt 2007-07-30 >> > 11:29:28.000000000 +0800 >> > @@ -31,11 +31,11 @@ >> > 0xb0 - 0x13f Free. Add more parameters here if you really need them. >> > 0x140- 0x1be EDID_INFO Video mode setup >> > >> > -0x1c4 unsigned long EFI system table pointer >> > -0x1c8 unsigned long EFI memory descriptor size >> > -0x1cc unsigned long EFI memory descriptor version >> > +0x1c4 unsigned long EFI system table pointer* >> > +0x1c8 unsigned long EFI memory descriptor size* >> > +0x1cc unsigned long EFI memory descriptor version* >> > 0x1d0 unsigned long EFI memory descriptor map pointer >> > -0x1d4 unsigned long EFI memory descriptor map size >> > +0x1d4 unsigned long EFI memory descriptor map size* >> > 0x1e0 unsigned long ALT_MEM_K, alternative mem check, in Kb >> > 0x1e4 unsigned long Scratch field for the kernel setup code >> > 0x1e8 char number of entries in E820MAP (below) >> > @@ -87,3 +87,13 @@ >> > 0x2d0 - 0xd00 E820MAP >> > 0xd00 - 0xeff EDDBUF (edd.S) for disk signature read sector >> > 0xd00 - 0xeeb EDDBUF (edd.S) for edd data >> > + >> > +Changes for x86_64 implementation: >> > +--------------------------------- >> > +For alignment purposes, the following parameters are rearranged. >> > + >> > +0x1b8 unsigned long EFI system table pointer >> > +0x1c0 unsigned long EFI Loader signature >> > +0x1c4 unsigned long EFI memory descriptor size >> > +0x1c8 unsigned long EFI memory descriptor version >> > +0x1cc unsigned long EFI memory descriptor map size >> >> Huh? It is the same protocol. Unless there are specific issues such >> as pointers being to small we should remain 100% the same for both >> arch/i386 and arch/x86_64 This variation looks like a serious >> bug. > > The parameters are rearranged, because the pointer is too small. For > example, the EFI system table pointer is 8 bytes in x86_64, while it is > 4 bytes in i386.
Ok. I see what is happening. When the documentation is for arch/i386 unsigned long is 4 bytes, and you are using unsigned long to mean 8 bytes. For an 8 byte fields please just spell out the size as 8 bytes. How does EFI handle 32bit/64bit compatibility? In particular how do I load a 32bit kernel on machine with a 64bit EFI? Can it be done? Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
