From a24e785111a32ccb7cebafd24b1b1cb474ea8e5d Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sun, 21 Oct 2007 16:41:35 -0700 Subject: 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 Signed-off-by: Rusty Russell Acked-by: H. Peter Anvin Cc: "Eric W. Biederman" Cc: Vivek Goyal Cc: James Bottomley Cc: Zachary Amsden Cc: Andi Kleen Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/boot/compressed/head_32.S | 15 +++++++++++++-- arch/x86/boot/compressed/misc_32.c | 3 +++ arch/x86/boot/header.S | 7 ++++++- 3 files changed, 22 insertions(+), 3 deletions(-) (limited to 'arch/x86/boot') diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index f35ea22..a0ae2e7 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -27,13 +27,22 @@ #include #include #include +#include .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 1dc1e19..b74d60d 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; diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S index f3140e5..8353c81 100644 --- a/arch/x86/boot/header.S +++ b/arch/x86/boot/header.S @@ -119,7 +119,7 @@ _start: # Part 2 of the header, from the old setup.S .ascii "HdrS" # header signature - .word 0x0206 # header version number (>= 0x0105) + .word 0x0207 # header version number (>= 0x0105) # or else old loadlin-1.5 will fail) .globl realmode_swtch realmode_swtch: .word 0, 0 # default_switch, SETUPSEG @@ -214,6 +214,11 @@ cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line, #added with boot protocol #version 2.06 +hardware_subarch: .long 0 # subarchitecture, added with 2.07 + # default to 0 for normal x86 PC + +hardware_subarch_data: .quad 0 + # End of setup header ##################################################### .section ".inittext", "ax" -- cgit v1.1