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redesign of the boot code of the application processor

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This commit is contained in:
Stefan Lankes 2011-07-18 08:35:57 +02:00
parent 1fb1379a9c
commit e7c0f53562
1 changed files with 32 additions and 64 deletions
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94
tools/smp_setup.asm
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@ -22,55 +22,10 @@
[BITS 16] [BITS 16]
SECTION .text SECTION .text
GLOBAL _start GLOBAL _start
ORG 0x10000 ORG 0x7000
_start: _start:
jmp _realstart cli
lgdt [gdtr]
struc GDT_STR
s0_15: resw 1
b0_15: resw 1
b16_23: resb 1
flags: resb 1
access: resb 1
b24_31: resb 1
endstruc
gdt_start dw gdt_size
gdt_ptr dd dummy_descriptor
dummy_descriptor: istruc GDT_STR
at s0_15, dw 0
at b0_15, dw 0
at b16_23, db 0
at flags, db 0
at access, db 0
at b24_31, db 0
iend
; 4GB 32-bit code , 9ah = 10011010b = Present, DPL 00,No System, Code Exec/Read.
code32_descriptor: istruc GDT_STR
at s0_15, dw 0x0ffff
at b0_15, dw 0
at b16_23, db 0
at flags, db 0x9a
at access, db 0xcf
at b24_31, db 0
iend
; 4GB 32-bit data, 92h = 10010010b = Present, DPL 00, No System, Data Read/Write
data32_descriptor: istruc GDT_STR
at s0_15, dw 0x0ffff
at b0_15, dw 0
at b16_23, db 0
at flags, db 0x92
at access, db 0xcf
at b24_31, db 0
iend
gdt_size equ $ - (dummy_descriptor) - 1
_realstart:
lgdt [gdt_start]
; switch to protected mode by setting PE bit ; switch to protected mode by setting PE bit
mov eax, cr0 mov eax, cr0
@ -78,28 +33,41 @@ _realstart:
mov cr0, eax mov cr0, eax
; far jump to the 32bit code ; far jump to the 32bit code
jmp dword 0x08 : _pmstart jmp dword codesel : _pmstart
[BITS 32] [BITS 32]
_pmstart: _pmstart:
cli
xor eax, eax xor eax, eax
mov ax, 0x10 mov ax, datasel
mov ds, ax mov ds, ax
mov es, ax mov es, ax
mov fs, ax mov fs, ax
mov gs, ax mov gs, ax
mov ss, ax mov ss, ax
; enable cache and turn on FPU exceptions
mov eax, cr0
and eax, 0x9fffffff
or eax, 0x20
mov cr0, eax
; clear the current pgd entry
xor eax, eax
mov cr3, eax
; set stack pointer
mov esp, 0xDEADBEEF mov esp, 0xDEADBEEF
xor eax, eax push DWORD 0xDEADDEAD
xor ebx, ebx push DWORD 0x00 ; dummy value
jmp 0x08 : 0xDEADC0DE jmp codesel : 0xDEADC0DE
jmp $
gdtr: ; descritor table
dw gdt_end-gdt-1 ; limit
dd gdt ; base adresse
gdt:
dd 0,0 ; null descriptor
codesel equ $-gdt
dw 0xFFFF ; segment size 0..15
dw 0x0000 ; segment address 0..15
db 0x00 ; segment address 16..23
db 0x9A ; access permissions und type
db 0xCF ; additional information and segment size 16...19
db 0x00 ; segment address 24..31
datasel equ $-gdt
dw 0xFFFF ; segment size 0..15
dw 0x0000 ; segment address 0..15
db 0x00 ; segment address 16..23
db 0x92 ; access permissions and type
db 0xCF ; additional informationen and degment size 16...19
db 0x00 ; segment address 24..31
gdt_end: