2009-08-14 Pavel Roskin <proski@gnu.org>
* boot/i386/pc/cdboot.S: Use LOCAL for local labels. Eliminate ABS and APPLE_CC. * boot/i386/pc/diskboot.S: Likewise. * boot/i386/pc/lnxboot.S: Likewise. Hardcode the number of code sectors allow compilation on MacOSX. * conf/i386-pc.rmk: Enable unconditional compilation of lnxboot.img.
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proski
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5 changed files with 63 additions and 164 deletions
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@ -16,23 +16,14 @@
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <grub/symbol.h>
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#include <grub/machine/boot.h>
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/*
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* defines for the code go here
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*/
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/* Absolute addresses
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This makes the assembler generate the address without support
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from the linker. (ELF can't relocate 16-bit addresses!) */
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#define ABS(x) (x-_start+GRUB_BOOT_MACHINE_KERNEL_ADDR)
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/* Print message string */
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#ifdef APPLE_CC
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#define MSG(x) x ## _abs = ABS(x); mov $x ## _abs, %esi; call message
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#else
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#define MSG(x) movw $ABS(x), %si; call message
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#endif
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#define MSG(x) movw $x, %si; call LOCAL(message)
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.file "diskboot.S"
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@ -65,33 +56,27 @@ _start:
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popw %si
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/* this sets up for the first run through "bootloop" */
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#ifdef APPLE_CC
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firstlist_off_abs = ABS (firstlist - GRUB_BOOT_MACHINE_LIST_SIZE)
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movl $firstlist_off_abs, %edi
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#else
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movw $ABS(firstlist - GRUB_BOOT_MACHINE_LIST_SIZE), %di
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#endif
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movw $(firstlist - GRUB_BOOT_MACHINE_LIST_SIZE), %di
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/* save the sector number of the second sector in %ebp */
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movl (%di), %ebp
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/* this is the loop for reading the rest of the kernel in */
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bootloop:
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LOCAL(bootloop):
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/* check the number of sectors to read */
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cmpw $0, 8(%di)
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/* if zero, go to the start function */
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je bootit
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je LOCAL(bootit)
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setup_sectors:
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LOCAL(setup_sectors):
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/* check if we use LBA or CHS */
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cmpb $0, -1(%si)
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/* jump to chs_mode if zero */
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je chs_mode
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/* use CHS if zero, LBA otherwise */
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je LOCAL(chs_mode)
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lba_mode:
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/* load logical sector start */
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movl (%di), %ebx
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movl 4(%di), %ecx
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@ -150,16 +135,16 @@ lba_mode:
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movb $0x42, %ah
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int $0x13
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jc read_error
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jc LOCAL(read_error)
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movw $GRUB_BOOT_MACHINE_BUFFER_SEG, %bx
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jmp copy_buffer
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jmp LOCAL(copy_buffer)
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chs_mode:
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LOCAL(chs_mode):
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/* load logical sector start (top half) */
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movl 4(%di), %eax
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orl %eax, %eax
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jnz geometry_error
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jnz LOCAL(geometry_error)
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/* load logical sector start (bottom half) */
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movl (%di), %eax
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@ -184,7 +169,7 @@ chs_mode:
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/* do we need too many cylinders? */
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cmpw 8(%si), %ax
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jge geometry_error
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jge LOCAL(geometry_error)
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/* determine the maximum sector length of this read */
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movw (%si), %ax /* get number of sectors per track/head */
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@ -254,12 +239,12 @@ chs_mode:
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movb $0x2, %ah /* function 2 */
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int $0x13
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jc read_error
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jc LOCAL(read_error)
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/* save source segment */
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movw %es, %bx
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copy_buffer:
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LOCAL(copy_buffer):
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/* load addresses for copy from disk buffer to destination */
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movw 10(%di), %es /* load destination segment */
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@ -299,17 +284,17 @@ copy_buffer:
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/* check if finished with this dataset */
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cmpw $0, 8(%di)
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jne setup_sectors
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jne LOCAL(setup_sectors)
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/* update position to load from */
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subw $GRUB_BOOT_MACHINE_LIST_SIZE, %di
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/* jump to bootloop */
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jmp bootloop
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jmp LOCAL(bootloop)
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/* END OF MAIN LOOP */
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bootit:
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LOCAL(bootit):
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/* print a newline */
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MSG(notification_done)
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popw %dx /* this makes sure %dl is our "boot" drive */
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@ -319,21 +304,21 @@ bootit:
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/*
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* BIOS Geometry translation error (past the end of the disk geometry!).
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*/
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geometry_error:
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LOCAL(geometry_error):
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MSG(geometry_error_string)
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jmp general_error
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jmp LOCAL(general_error)
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/*
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* Read error on the disk.
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*/
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read_error:
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LOCAL(read_error):
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MSG(read_error_string)
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general_error:
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LOCAL(general_error):
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MSG(general_error_string)
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/* go here when you need to stop the machine hard after an error condition */
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stop: jmp stop
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LOCAL(stop): jmp LOCAL(stop)
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notification_string: .asciz "loading"
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@ -361,12 +346,11 @@ general_error_string: .asciz " Error"
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int $0x10 /* display a byte */
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incw %si
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message:
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LOCAL(message):
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movb (%si), %al
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cmpb $0, %al
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jne 1b /* if not end of string, jmp to display */
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ret
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lastlist:
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/*
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* This area is an empty space between the main body of code below which
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