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Diffstat (limited to 'arch/x86/boot/header.S')
-rw-r--r--arch/x86/boot/header.S29
1 files changed, 9 insertions, 20 deletions
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 7ccff4884a2..5d84d1c74e4 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -24,12 +24,8 @@
#include "boot.h"
#include "offsets.h"
-SETUPSECTS = 4 /* default nr of setup-sectors */
BOOTSEG = 0x07C0 /* original address of boot-sector */
-SYSSEG = DEF_SYSSEG /* system loaded at 0x10000 (65536) */
-SYSSIZE = DEF_SYSSIZE /* system size: # of 16-byte clicks */
- /* to be loaded */
-ROOT_DEV = 0 /* ROOT_DEV is now written by "build" */
+SYSSEG = 0x1000 /* historical load address >> 4 */
#ifndef SVGA_MODE
#define SVGA_MODE ASK_VGA
@@ -97,12 +93,12 @@ bugger_off_msg:
.section ".header", "a"
.globl hdr
hdr:
-setup_sects: .byte SETUPSECTS
+setup_sects: .byte 0 /* Filled in by build.c */
root_flags: .word ROOT_RDONLY
-syssize: .long SYSSIZE
-ram_size: .word RAMDISK
+syssize: .long 0 /* Filled in by build.c */
+ram_size: .word 0 /* Obsolete */
vid_mode: .word SVGA_MODE
-root_dev: .word ROOT_DEV
+root_dev: .word 0 /* Filled in by build.c */
boot_flag: .word 0xAA55
# offset 512, entry point
@@ -123,14 +119,15 @@ _start:
# or else old loadlin-1.5 will fail)
.globl realmode_swtch
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
-start_sys_seg: .word SYSSEG
+start_sys_seg: .word SYSSEG # obsolete and meaningless, but just
+ # in case something decided to "use" it
.word kernel_version-512 # pointing to kernel version string
# above section of header is compatible
# with loadlin-1.5 (header v1.5). Don't
# change it.
-type_of_loader: .byte 0 # = 0, old one (LILO, Loadlin,
- # Bootlin, SYSLX, bootsect...)
+type_of_loader: .byte 0 # 0 means ancient bootloader, newer
+ # bootloaders know to change this.
# See Documentation/i386/boot.txt for
# assigned ids
@@ -142,11 +139,7 @@ CAN_USE_HEAP = 0x80 # If set, the loader also has set
# space behind setup.S can be used for
# heap purposes.
# Only the loader knows what is free
-#ifndef __BIG_KERNEL__
- .byte 0
-#else
.byte LOADED_HIGH
-#endif
setup_move_size: .word 0x8000 # size to move, when setup is not
# loaded at 0x90000. We will move setup
@@ -157,11 +150,7 @@ setup_move_size: .word 0x8000 # size to move, when setup is not
code32_start: # here loaders can put a different
# start address for 32-bit code.
-#ifndef __BIG_KERNEL__
- .long 0x1000 # 0x1000 = default for zImage
-#else
.long 0x100000 # 0x100000 = default for big kernel
-#endif
ramdisk_image: .long 0 # address of loaded ramdisk image
# Here the loader puts the 32-bit