From 85414b693ac037d709582a167a330db3a5d186d8 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 11 Jul 2007 12:18:33 -0700 Subject: 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 Signed-off-by: Linus Torvalds --- arch/i386/boot/compressed/head.S | 6 +++--- arch/x86_64/boot/compressed/head.S | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/i386/boot/compressed/head.S b/arch/i386/boot/compressed/head.S index 3517a32aaf4..f35ea223752 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 f9d5692a010..1312bfaff30 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 -- cgit v1.2.3