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-rw-r--r--arch/i386/boot/bootsect.S98
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diff --git a/arch/i386/boot/bootsect.S b/arch/i386/boot/bootsect.S
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+/*
+ * bootsect.S Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * modified by Drew Eckhardt
+ * modified by Bruce Evans (bde)
+ * modified by Chris Noe (May 1999) (as86 -> gas)
+ * gutted by H. Peter Anvin (Jan 2003)
+ *
+ * BIG FAT NOTE: We're in real mode using 64k segments. Therefore segment
+ * addresses must be multiplied by 16 to obtain their respective linear
+ * addresses. To avoid confusion, linear addresses are written using leading
+ * hex while segment addresses are written as segment:offset.
+ *
+ */
+
+#include <asm/boot.h>
+
+SETUPSECTS = 4 /* default nr of setup-sectors */
+BOOTSEG = 0x07C0 /* original address of boot-sector */
+INITSEG = DEF_INITSEG /* we move boot here - out of the way */
+SETUPSEG = DEF_SETUPSEG /* setup starts here */
+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" */
+SWAP_DEV = 0 /* SWAP_DEV is now written by "build" */
+
+#ifndef SVGA_MODE
+#define SVGA_MODE ASK_VGA
+#endif
+
+#ifndef RAMDISK
+#define RAMDISK 0
+#endif
+
+#ifndef ROOT_RDONLY
+#define ROOT_RDONLY 1
+#endif
+
+.code16
+.text
+
+.global _start
+_start:
+
+ # Normalize the start address
+ jmpl $BOOTSEG, $start2
+
+start2:
+ movw %cs, %ax
+ movw %ax, %ds
+ movw %ax, %es
+ movw %ax, %ss
+ movw $0x7c00, %sp
+ sti
+ cld
+
+ movw $bugger_off_msg, %si
+
+msg_loop:
+ lodsb
+ andb %al, %al
+ jz die
+ movb $0xe, %ah
+ movw $7, %bx
+ int $0x10
+ jmp msg_loop
+
+die:
+ # Allow the user to press a key, then reboot
+ xorw %ax, %ax
+ int $0x16
+ int $0x19
+
+ # int 0x19 should never return. In case it does anyway,
+ # invoke the BIOS reset code...
+ ljmp $0xf000,$0xfff0
+
+
+bugger_off_msg:
+ .ascii "Direct booting from floppy is no longer supported.\r\n"
+ .ascii "Please use a boot loader program instead.\r\n"
+ .ascii "\n"
+ .ascii "Remove disk and press any key to reboot . . .\r\n"
+ .byte 0
+
+
+ # Kernel attributes; used by setup
+
+ .org 497
+setup_sects: .byte SETUPSECTS
+root_flags: .word ROOT_RDONLY
+syssize: .word SYSSIZE
+swap_dev: .word SWAP_DEV
+ram_size: .word RAMDISK
+vid_mode: .word SVGA_MODE
+root_dev: .word ROOT_DEV
+boot_flag: .word 0xAA55