diff options
| author | H. Peter Anvin <hpa@zytor.com> | 2007-07-11 12:18:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-12 10:55:54 -0700 |
| commit | 85414b693ac037d709582a167a330db3a5d186d8 (patch) | |
| tree | 78836556d59e28c335d2ba5be347c06f4298432e | |
| parent | 1d67953f2bda8876045c24ae58841f27d9bb7572 (diff) | |
Define zero-page offset 0x1e4 as a scratch field, and use it
The relocatable kernel code needs a scratch field for the decompressor
to determine its own location. It was using a location inside
struct screen_info; reserve a free location and document it as scratch
instead.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | Documentation/i386/zero-page.txt | 1 | ||||
| -rw-r--r-- | arch/i386/boot/compressed/head.S | 6 | ||||
| -rw-r--r-- | arch/x86_64/boot/compressed/head.S | 6 |
3 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/i386/zero-page.txt b/Documentation/i386/zero-page.txt index c04a421f4a7c..75b3680c41eb 100644 --- a/Documentation/i386/zero-page.txt +++ b/Documentation/i386/zero-page.txt @@ -37,6 +37,7 @@ Offset Type Description 0x1d0 unsigned long EFI memory descriptor map pointer 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) 0x1e9 unsigned char number of entries in EDDBUF (below) 0x1ea unsigned char number of entries in EDD_MBR_SIG_BUFFER (below) diff --git a/arch/i386/boot/compressed/head.S b/arch/i386/boot/compressed/head.S index 3517a32aaf41..f35ea2237522 100644 --- a/arch/i386/boot/compressed/head.S +++ b/arch/i386/boot/compressed/head.S @@ -45,10 +45,10 @@ startup_32: * at and where we were actually loaded at. This can only be done * with a short local call on x86. Nothing else will tell us what * address we are running at. The reserved chunk of the real-mode - * data at 0x34-0x3f are used as the stack for this calculation. - * Only 4 bytes are needed. + * data at 0x1e4 (defined as a scratch field) are used as the stack + * for this calculation. Only 4 bytes are needed. */ - leal 0x40(%esi), %esp + leal (0x1e4+4)(%esi), %esp call 1f 1: popl %ebp subl $1b, %ebp diff --git a/arch/x86_64/boot/compressed/head.S b/arch/x86_64/boot/compressed/head.S index f9d5692a0106..1312bfaff306 100644 --- a/arch/x86_64/boot/compressed/head.S +++ b/arch/x86_64/boot/compressed/head.S @@ -46,10 +46,10 @@ startup_32: * at and where we were actually loaded at. This can only be done * with a short local call on x86. Nothing else will tell us what * address we are running at. The reserved chunk of the real-mode - * data at 0x34-0x3f are used as the stack for this calculation. - * Only 4 bytes are needed. + * data at 0x1e4 (defined as a scratch field) are used as the stack + * for this calculation. Only 4 bytes are needed. */ - leal 0x40(%esi), %esp + leal (0x1e4+4)(%esi), %esp call 1f 1: popl %ebp subl $1b, %ebp |