diff options
Diffstat (limited to 'setup.S')
| -rw-r--r-- | setup.S | 230 |
1 files changed, 115 insertions, 115 deletions
@@ -1,115 +1,115 @@ -/* - * setup.s is responsible for getting the system data from the BIOS, - * and putting them into the appropriate places in system memory. - * both setup.s and system has been loaded by the bootblock. - * - * 1-Jan-96 Modified by Chris Brady for use as a boot/loader for memtest-86. - */ - -#define __ASSEMBLY__ -#include "defs.h" - -.code16 -.section ".setup", "ax", @progbits -.globl start -start: -# ok, the read went well -# now we want to move to protected mode ... - - - cli # no interrupts allowed # - movb $0x80, %al # disable NMI for the bootup sequence - outb %al, $0x70 - -# The system will move itself to its rightful place. - - push %cs - pop %ds - lidt idt_48 - start # load idt with 0,0 - lgdt gdt_48 - start # load gdt with whatever appropriate - -# that was painless, now we enable A20 - - call empty_8042 - - movb $0xD1, %al # command write - outb %al, $0x64 - call empty_8042 - - movb $0xDF, %al # A20 on - outb %al, $0x60 - call empty_8042 - -/* - * Note that the short jump isn't strictly needed, althought there are - * reasons why it might be a good idea. It won't hurt in any case. - */ - movw $0x0001, %ax # protected mode (PE) bit - lmsw %ax # This is it# - jmp flush_instr -flush_instr: - movw $KERNEL_DS, %ax - movw %ax, %ds - movw %ax, %es - movw %ax, %ss - movw %ax, %fs - movw %ax, %gs - -data32 ljmp $KERNEL_CS, $(TSTLOAD <<4) # jmp offset 2000 of segment 0x10 (cs) - -/* - * This routine checks that the keyboard command queue is empty - * (after emptying the output buffers) - * - * No timeout is used - if this hangs there is something wrong with - * the machine, and we probably couldn't proceed anyway. - */ -empty_8042: - call delay - inb $0x64, %al # 8042 status port - testb $1, %al # output buffer? - jz no_output - call delay - inb $0x60, %al # read it - jmp empty_8042 - -no_output: - testb $2, %al # is input buffer full? - jnz empty_8042 # yes - loop - ret -# -# Delay is needed after doing i/o -# -delay: - .word 0x00eb # jmp $+2 - ret - -gdt: - .word 0,0,0,0 # dummy - - .word 0,0,0,0 # unused - - .word 0x7FFF # limit 128mb - .word 0x0000 # base address=0 - .word 0x9A00 # code read/exec - .word 0x00C0 # granularity=4096, 386 - - .word 0x7FFF # limit 128mb - .word 0x0000 # base address=0 - .word 0x9200 # data read/write - .word 0x00C0 # granularity=4096, 386 - -idt_48: - .word 0 # idt limit=0 - .long 0 # idt base=0L - -gdt_48: - .word 0x800 # gdt limit=2048, 256 GDT entries - .word 512+gdt - start,0x9 # gdt base = 0X9xxxx - -msg1: - .asciz "Setup.S\r\n" - - /* Pad setup to the proper size */ - .org (SETUPSECS*512) - +/*
+ * setup.s is responsible for getting the system data from the BIOS,
+ * and putting them into the appropriate places in system memory.
+ * both setup.s and system has been loaded by the bootblock.
+ *
+ * 1-Jan-96 Modified by Chris Brady for use as a boot/loader for memtest-86.
+ */
+
+#define __ASSEMBLY__
+#include "defs.h"
+
+.code16
+.section ".setup", "ax", @progbits
+.globl start
+start:
+# ok, the read went well
+# now we want to move to protected mode ...
+
+
+ cli # no interrupts allowed #
+ movb $0x80, %al # disable NMI for the bootup sequence
+ outb %al, $0x70
+
+# The system will move itself to its rightful place.
+
+ push %cs
+ pop %ds
+ lidt idt_48 - start # load idt with 0,0
+ lgdt gdt_48 - start # load gdt with whatever appropriate
+
+# that was painless, now we enable A20
+
+ call empty_8042
+
+ movb $0xD1, %al # command write
+ outb %al, $0x64
+ call empty_8042
+
+ movb $0xDF, %al # A20 on
+ outb %al, $0x60
+ call empty_8042
+
+/*
+ * Note that the short jump isn't strictly needed, althought there are
+ * reasons why it might be a good idea. It won't hurt in any case.
+ */
+ movw $0x0001, %ax # protected mode (PE) bit
+ lmsw %ax # This is it#
+ jmp flush_instr
+flush_instr:
+ movw $KERNEL_DS, %ax
+ movw %ax, %ds
+ movw %ax, %es
+ movw %ax, %ss
+ movw %ax, %fs
+ movw %ax, %gs
+
+data32 ljmp $KERNEL_CS, $(TSTLOAD <<4) # jmp offset 2000 of segment 0x10 (cs)
+
+/*
+ * This routine checks that the keyboard command queue is empty
+ * (after emptying the output buffers)
+ *
+ * No timeout is used - if this hangs there is something wrong with
+ * the machine, and we probably couldn't proceed anyway.
+ */
+empty_8042:
+ call delay
+ inb $0x64, %al # 8042 status port
+ testb $1, %al # output buffer?
+ jz no_output
+ call delay
+ inb $0x60, %al # read it
+ jmp empty_8042
+
+no_output:
+ testb $2, %al # is input buffer full?
+ jnz empty_8042 # yes - loop
+ ret
+#
+# Delay is needed after doing i/o
+#
+delay:
+ .word 0x00eb # jmp $+2
+ ret
+
+gdt:
+ .word 0,0,0,0 # dummy
+
+ .word 0,0,0,0 # unused
+
+ .word 0x7FFF # limit 128mb
+ .word 0x0000 # base address=0
+ .word 0x9A00 # code read/exec
+ .word 0x00C0 # granularity=4096, 386
+
+ .word 0x7FFF # limit 128mb
+ .word 0x0000 # base address=0
+ .word 0x9200 # data read/write
+ .word 0x00C0 # granularity=4096, 386
+
+idt_48:
+ .word 0 # idt limit=0
+ .long 0 # idt base=0L
+
+gdt_48:
+ .word 0x800 # gdt limit=2048, 256 GDT entries
+ .word 512+gdt - start,0x9 # gdt base = 0X9xxxx
+
+msg1:
+ .asciz "Setup.S\r\n"
+
+ /* Pad setup to the proper size */
+ .org (SETUPSECS*512)
+
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