2005-07-16 Yoshinori K. Okuji <okuji@enbug.org>
* kern/i386/pc/startup.S (grub_gate_a20): Rewritten for robustness. This routine now supports a BIOS call and System Control Port A to modify the gate A20. * include/grub/i386/pc/kernel.h (GRUB_KERNEL_MACHINE_RAW_SIZE): Increased to 0x440.
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okuji
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654fc59fe4
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@ -1,3 +1,12 @@
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2005-07-16 Yoshinori K. Okuji <okuji@enbug.org>
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* kern/i386/pc/startup.S (grub_gate_a20): Rewritten for
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robustness. This routine now supports a BIOS call and System
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Control Port A to modify the gate A20.
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* include/grub/i386/pc/kernel.h (GRUB_KERNEL_MACHINE_RAW_SIZE):
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Increased to 0x440.
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2005-07-12 Hollis Blanchard <hollis@penguinppc.org>
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* disk/powerpc/ieee1275/ofdisk.c (grub_ofdisk_open): dprintf the
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@ -39,7 +39,7 @@
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#define GRUB_KERNEL_MACHINE_PREFIX 0x1c
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/* The size of the first region which won't be compressed. */
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#define GRUB_KERNEL_MACHINE_RAW_SIZE 0x400
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#define GRUB_KERNEL_MACHINE_RAW_SIZE 0x440
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#ifndef ASM_FILE
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@ -125,7 +125,7 @@ codestart:
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/* reset disk system (%ah = 0) */
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int $0x13
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/* transition to protected mode */
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DATA32 call real_to_prot
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@ -134,7 +134,7 @@ codestart:
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incl %eax
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call EXT_C(grub_gate_a20)
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/* decompress the compressed part and put the result at 1MB */
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movl $0x100000, %esi
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movl $(START_SYMBOL + GRUB_KERNEL_MACHINE_RAW_SIZE), %edi
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@ -384,51 +384,132 @@ realcseg:
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*/
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FUNCTION(grub_gate_a20)
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movl %eax, %ecx
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movl %eax, %edx
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call gloop1
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gate_a20_test_current_state:
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/* first of all, test if already in a good state */
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call gate_a20_check_state
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cmpb %al, %dl
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jnz gate_a20_try_bios
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ret
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gate_a20_try_bios:
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/* second, try a BIOS call */
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pushl %ebp
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call EXT_C(prot_to_real)
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.code16
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movw $0x2400, %ax
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testb %dl, %dl
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jz 1f
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incw %ax
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1: int $0x15
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DATA32 call EXT_C(real_to_prot)
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.code32
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popl %ebp
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call gate_a20_check_state
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cmpb %al, %dl
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jnz gate_a20_try_keyboard_controller
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ret
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gate_a20_flush_keyboard_buffer:
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inb $0x64
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andb $0x02, %al
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jnz gate_a20_flush_keyboard_buffer
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2:
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inb $0x64
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andb $0x01, %al
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jz 3f
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inb $0x60
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jmp 2b
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3:
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ret
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gate_a20_try_keyboard_controller:
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/* third, try the keyboard controller */
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call gate_a20_flush_keyboard_buffer
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movb $0xd1, %al
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outb $0x64
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gloopint1:
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4:
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inb $0x64
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andb $0x02, %al
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jnz gloopint1
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jnz 4b
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movb $0xdd, %al
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testl %ecx, %ecx
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jz gdoit
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testb %dl, %dl
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jz 5f
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orb $0x02, %al
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gdoit:
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outb $0x60
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call gloop1
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5: outb $0x60
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call gate_a20_flush_keyboard_buffer
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/* output a dummy command (USB keyboard hack) */
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movb $0xff, %al
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outb $0x64
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call gloop1
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call gate_a20_flush_keyboard_buffer
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call gate_a20_check_state
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cmpb %al, %dl
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jnz gate_a20_try_system_control_port_a
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ret
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gloop1:
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inb $0x64
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andb $0x02, %al
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jnz gloop1
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gloop2:
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inb $0x64
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andb $0x01, %al
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jz gloop2ret
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inb $0x60
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jmp gloop2
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gloop2ret:
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gate_a20_try_system_control_port_a:
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/* fourth, try the system control port A */
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inb $0x92
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andb $(~0x03), %al
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testb %dl, %dl
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jz 6f
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orb $0x02, %al
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6: outb $0x92
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call gate_a20_check_state
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cmpb %al, %dl
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/* everything failed, so restart from the beginning */
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jnz gate_a20_try_bios
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ret
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gate_a20_check_state:
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/* iterate the checking for a while */
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movl $100, %ecx
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1:
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call 3f
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cmpb %al, %dl
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jz 2f
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loop 1b
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2:
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ret
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3:
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pushl %ebx
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pushl %ecx
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xorl %eax, %eax
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/* compare the byte at 0x2000 with that at 0x102000 */
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movl $GRUB_BOOT_MACHINE_KERNEL_ADDR, %ebx
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pushl %ebx
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/* save the original byte in CL */
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movb (%ebx), %cl
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/* store the value at 0x102000 in AL */
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addl $0x100000, %ebx
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movb (%ebx), %al
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/* try to set one less value at 0x2000 */
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popl %ebx
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movb %al, %ch
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decb %ch
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movb %ch, (%ebx)
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/* serialize */
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outb $0x80
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outb $0x80
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/* store the value at 0x2000 in CH */
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movb (%ebx), %ch
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/* this result is 1 if A20 is on or 0 if it is off */
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subb %ch, %al
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/* restore the original */
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movb %cl, (%ebx)
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popl %ecx
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popl %ebx
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ret
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#include "lzo1x.S"
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