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authorRusty Russell <rusty@rustcorp.com.au>2007-10-22 01:41:35 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-22 17:13:17 +0200
commita24e785111a32ccb7cebafd24b1b1cb474ea8e5d (patch)
tree63ec9334e60f2b4a50521312a5152071fa339911 /arch/x86/boot/compressed
parentadd WEAK() for creating weak asm labels (diff)
downloadlinux-a24e785111a32ccb7cebafd24b1b1cb474ea8e5d.tar.xz
linux-a24e785111a32ccb7cebafd24b1b1cb474ea8e5d.zip
i386: paravirt boot sequence
This patch uses the updated boot protocol to do paravirtualized boot. If the boot version is >= 2.07, then it will do two things: 1. Check the bootparams loadflags to see if we should reload the segment registers and clear interrupts. This is appropriate for normal native boot and some paravirtualized environments, but inapproprate for others. 2. Check the hardware architecture, and dispatch to the appropriate kernel entrypoint. If the bootloader doesn't set this, then we simply do the normal boot sequence. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Andi Kleen <ak@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/boot/compressed')
-rw-r--r--arch/x86/boot/compressed/head_32.S15
-rw-r--r--arch/x86/boot/compressed/misc_32.c3
2 files changed, 16 insertions, 2 deletions
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index f35ea2237522..a0ae2e7f6cec 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -27,13 +27,22 @@
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/boot.h>
+#include <asm/asm-offsets.h>
.section ".text.head","ax",@progbits
.globl startup_32
startup_32:
- cld
- cli
+ /* check to see if KEEP_SEGMENTS flag is meaningful */
+ cmpw $0x207, BP_version(%esi)
+ jb 1f
+
+ /* test KEEP_SEGMENTS flag to see if the bootloader is asking
+ * us to not reload segments */
+ testb $(1<<6), BP_loadflags(%esi)
+ jnz 2f
+
+1: cli
movl $(__BOOT_DS),%eax
movl %eax,%ds
movl %eax,%es
@@ -41,6 +50,8 @@ startup_32:
movl %eax,%gs
movl %eax,%ss
+2: cld
+
/* Calculate the delta between where we were compiled to run
* 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
diff --git a/arch/x86/boot/compressed/misc_32.c b/arch/x86/boot/compressed/misc_32.c
index 1dc1e19c0a9f..b74d60d1b2fa 100644
--- a/arch/x86/boot/compressed/misc_32.c
+++ b/arch/x86/boot/compressed/misc_32.c
@@ -247,6 +247,9 @@ static void putstr(const char *s)
int x,y,pos;
char c;
+ if (RM_SCREEN_INFO.orig_video_mode == 0 && lines == 0 && cols == 0)
+ return;
+
x = RM_SCREEN_INFO.orig_x;
y = RM_SCREEN_INFO.orig_y;