478 lines
8.5 KiB
NASM
478 lines
8.5 KiB
NASM
[BITS 32]
|
|
global start
|
|
start: mov esp, _sys_stack ; This points the stack to our new stack area
|
|
jmp stublet
|
|
|
|
|
|
; This part MUST be 4byte aligned, so we solve that issue using 'ALIGN 4'
|
|
ALIGN 4
|
|
mboot:
|
|
; Multiboot macros to make a few lines later more readable
|
|
MULTIBOOT_PAGE_ALIGN equ 1<<0
|
|
MULTIBOOT_MEMORY_INFO equ 1<<1
|
|
MULTIBOOT_AOUT_KLUDGE equ 1<<16
|
|
MULTIBOOT_HEADER_MAGIC equ 0x1BADB002
|
|
MULTIBOOT_HEADER_FLAGS equ MULTIBOOT_PAGE_ALIGN | MULTIBOOT_MEMORY_INFO | MULTIBOOT_AOUT_KLUDGE
|
|
MULTIBOOT_CHECKSUM equ -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)
|
|
EXTERN code, bss, end
|
|
|
|
; This is the GRUB Multiboot header. A boot signature
|
|
dd MULTIBOOT_HEADER_MAGIC
|
|
dd MULTIBOOT_HEADER_FLAGS
|
|
dd MULTIBOOT_CHECKSUM
|
|
|
|
; AOUT kludge - must be physical addresses. Make a note of these:
|
|
; The linker script fills in the data for these ones!
|
|
dd mboot
|
|
dd code
|
|
dd bss
|
|
dd end
|
|
dd start
|
|
|
|
; This is an endless loop here. Make a note of this: Later on, we
|
|
; will insert an 'extern _main', followed by 'call _main', right
|
|
; before the 'jmp $'.
|
|
stublet:
|
|
extern _main
|
|
call _main
|
|
jmp $
|
|
|
|
|
|
; !!! GDT !!!
|
|
; This will set up our new segment registers. We need to do
|
|
; something special in order to set CS. We do what is called a
|
|
; far jump. A jump that includes a segment as well as an offset.
|
|
; This is declared in C as 'extern void gdt_flush();'
|
|
|
|
global _gdt_flush ; Allows the C code to link to this
|
|
extern _gp ; Says that '_gp' is in another file
|
|
_gdt_flush:
|
|
lgdt [_gp] ; Load the GDT with our '_gp' which is a special pointer
|
|
mov ax, 0x10 ; 0x10 is the offset in the GDT to our data segment
|
|
mov ds, ax
|
|
mov es, ax
|
|
mov fs, ax
|
|
mov gs, ax
|
|
mov ss, ax
|
|
jmp 0x08:flush2 ; 0x08 is the offset to our code segment: Far jump!
|
|
flush2:
|
|
ret ; Returns back to the C code!
|
|
|
|
|
|
; !!! IDT !!!
|
|
; Loads the IDT defined in '_idtp'
|
|
global _idt_load
|
|
extern _idtp
|
|
_idt_load:
|
|
lidt [_idtp]
|
|
ret
|
|
|
|
; !!! ISRs !!!
|
|
global _isr0
|
|
global _isr1
|
|
global _isr2
|
|
global _isr3
|
|
global _isr4
|
|
global _isr5
|
|
global _isr6
|
|
global _isr7
|
|
global _isr8
|
|
global _isr9
|
|
global _isr10
|
|
global _isr11
|
|
global _isr12
|
|
global _isr13
|
|
global _isr14
|
|
global _isr15
|
|
global _isr16
|
|
global _isr17
|
|
global _isr18
|
|
global _isr19
|
|
global _isr20
|
|
global _isr21
|
|
global _isr22
|
|
global _isr23
|
|
global _isr24
|
|
global _isr25
|
|
global _isr26
|
|
global _isr27
|
|
global _isr28
|
|
global _isr29
|
|
global _isr30
|
|
global _isr31
|
|
|
|
_isr0:
|
|
cli
|
|
push byte 0; A normal ISR stub that pops a dummy error code to keep a
|
|
; uniform stack frame
|
|
push byte 0
|
|
jmp isr_common_stub
|
|
_isr1:
|
|
cli
|
|
push byte 0
|
|
push byte 1
|
|
jmp isr_common_stub
|
|
_isr2:
|
|
cli
|
|
push byte 0
|
|
push byte 2
|
|
jmp isr_common_stub
|
|
_isr3:
|
|
cli
|
|
push byte 0
|
|
push byte 3
|
|
jmp isr_common_stub
|
|
_isr4:
|
|
cli
|
|
push byte 0
|
|
push byte 4
|
|
jmp isr_common_stub
|
|
_isr5:
|
|
cli
|
|
push byte 0
|
|
push byte 5
|
|
jmp isr_common_stub
|
|
_isr6:
|
|
cli
|
|
push byte 0
|
|
push byte 6
|
|
jmp isr_common_stub
|
|
_isr7:
|
|
cli
|
|
push byte 0
|
|
push byte 7
|
|
jmp isr_common_stub
|
|
_isr8:
|
|
cli
|
|
push byte 8
|
|
jmp isr_common_stub
|
|
_isr9:
|
|
cli
|
|
push byte 0
|
|
push byte 9
|
|
jmp isr_common_stub
|
|
_isr10:
|
|
cli
|
|
push byte 10
|
|
jmp isr_common_stub
|
|
_isr11:
|
|
cli
|
|
push byte 11
|
|
jmp isr_common_stub
|
|
_isr12:
|
|
cli
|
|
push byte 12
|
|
jmp isr_common_stub
|
|
_isr13:
|
|
cli
|
|
push byte 13
|
|
jmp isr_common_stub
|
|
_isr14:
|
|
cli
|
|
push byte 14
|
|
jmp isr_common_stub
|
|
_isr15:
|
|
cli
|
|
push byte 0
|
|
push byte 15
|
|
jmp isr_common_stub
|
|
_isr16:
|
|
cli
|
|
push byte 0
|
|
push byte 16
|
|
jmp isr_common_stub
|
|
_isr17:
|
|
cli
|
|
push byte 0
|
|
push byte 17
|
|
jmp isr_common_stub
|
|
_isr18:
|
|
cli
|
|
push byte 0
|
|
push byte 18
|
|
jmp isr_common_stub
|
|
_isr19:
|
|
cli
|
|
push byte 0
|
|
push byte 19
|
|
jmp isr_common_stub
|
|
_isr20:
|
|
cli
|
|
push byte 0
|
|
push byte 20
|
|
jmp isr_common_stub
|
|
_isr21:
|
|
cli
|
|
push byte 0
|
|
push byte 21
|
|
jmp isr_common_stub
|
|
_isr22:
|
|
cli
|
|
push byte 0
|
|
push byte 22
|
|
jmp isr_common_stub
|
|
_isr23:
|
|
cli
|
|
push byte 0
|
|
push byte 23
|
|
jmp isr_common_stub
|
|
_isr24:
|
|
cli
|
|
push byte 0
|
|
push byte 24
|
|
jmp isr_common_stub
|
|
_isr25:
|
|
cli
|
|
push byte 0
|
|
push byte 25
|
|
jmp isr_common_stub
|
|
_isr26:
|
|
cli
|
|
push byte 0
|
|
push byte 26
|
|
jmp isr_common_stub
|
|
_isr27:
|
|
cli
|
|
push byte 0
|
|
push byte 27
|
|
jmp isr_common_stub
|
|
_isr28:
|
|
cli
|
|
push byte 0
|
|
push byte 28
|
|
jmp isr_common_stub
|
|
_isr29:
|
|
cli
|
|
push byte 0
|
|
push byte 29
|
|
jmp isr_common_stub
|
|
_isr30:
|
|
cli
|
|
push byte 0
|
|
push byte 30
|
|
jmp isr_common_stub
|
|
_isr31:
|
|
cli
|
|
push byte 0
|
|
push byte 31
|
|
jmp isr_common_stub
|
|
|
|
extern _fault_handler
|
|
|
|
isr_common_stub:
|
|
pusha
|
|
push ds
|
|
push es
|
|
push fs
|
|
push gs
|
|
mov ax, 0x10 ; Load the Kernel Data Segment descriptor!
|
|
mov ds, ax
|
|
mov es, ax
|
|
mov fs, ax
|
|
mov gs, ax
|
|
mov eax, esp ; Push us the stack
|
|
push eax
|
|
mov eax, _fault_handler
|
|
call eax ; A special call, preserves the 'eip' register
|
|
pop eax
|
|
pop gs
|
|
pop fs
|
|
pop es
|
|
pop ds
|
|
popa
|
|
add esp, 8 ; Cleans up the pushed error code and pushed ISR number
|
|
iret ; pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP!
|
|
|
|
|
|
; !!! IRQ !!!
|
|
global _irq0
|
|
global _irq1
|
|
global _irq2
|
|
global _irq3
|
|
global _irq4
|
|
global _irq5
|
|
global _irq6
|
|
global _irq7
|
|
global _irq8
|
|
global _irq9
|
|
global _irq10
|
|
global _irq11
|
|
global _irq12
|
|
global _irq13
|
|
global _irq14
|
|
global _irq15
|
|
|
|
; 32: IRQ0
|
|
_irq0:
|
|
cli
|
|
push byte 0
|
|
push byte 32; Note that these don't push an error code on the stack:
|
|
; We need to push a dummy error code
|
|
jmp irq_common_stub
|
|
|
|
; 33: IRQ1
|
|
_irq1:
|
|
cli
|
|
push byte 0
|
|
push byte 33
|
|
jmp irq_common_stub
|
|
|
|
; 34: IRQ2
|
|
_irq2:
|
|
cli
|
|
push byte 0
|
|
push byte 34
|
|
jmp irq_common_stub
|
|
|
|
; 35: IRQ3
|
|
_irq3:
|
|
cli
|
|
push byte 0
|
|
push byte 35
|
|
jmp irq_common_stub
|
|
|
|
; 36: IRQ4
|
|
_irq4:
|
|
cli
|
|
push byte 0
|
|
push byte 36
|
|
jmp irq_common_stub
|
|
|
|
; 37: IRQ5
|
|
_irq5:
|
|
cli
|
|
push byte 0
|
|
push byte 37
|
|
jmp irq_common_stub
|
|
|
|
; 38: IRQ6
|
|
_irq6:
|
|
cli
|
|
push byte 0
|
|
push byte 38
|
|
jmp irq_common_stub
|
|
|
|
; 39: IRQ7
|
|
_irq7:
|
|
cli
|
|
push byte 0
|
|
push byte 39
|
|
jmp irq_common_stub
|
|
|
|
; 40: IRQ8
|
|
_irq8:
|
|
cli
|
|
push byte 0
|
|
push byte 40
|
|
jmp irq_common_stub
|
|
; 41: IRQ9
|
|
_irq9:
|
|
cli
|
|
push byte 0
|
|
push byte 41
|
|
jmp irq_common_stub
|
|
|
|
; 42: IRQ10
|
|
_irq10:
|
|
cli
|
|
push byte 0
|
|
push byte 42
|
|
jmp irq_common_stub
|
|
|
|
; 43: IRQ11
|
|
_irq11:
|
|
cli
|
|
push byte 0
|
|
push byte 43
|
|
jmp irq_common_stub
|
|
|
|
; 44: IRQ12
|
|
_irq12:
|
|
cli
|
|
push byte 0
|
|
push byte 44
|
|
jmp irq_common_stub
|
|
|
|
; 45: IRQ13
|
|
_irq13:
|
|
cli
|
|
push byte 0
|
|
push byte 45
|
|
jmp irq_common_stub
|
|
|
|
; 46: IRQ14
|
|
_irq14:
|
|
cli
|
|
push byte 0
|
|
push byte 46
|
|
jmp irq_common_stub
|
|
|
|
; 47: IRQ15
|
|
_irq15:
|
|
cli
|
|
push byte 0
|
|
push byte 47
|
|
jmp irq_common_stub
|
|
|
|
extern _irq_handler
|
|
|
|
; This is a stub that we have created for IRQ based ISRs. This calls
|
|
; '_irq_handler' in our C code. We need to create this in an 'irq.c'
|
|
irq_common_stub:
|
|
pusha
|
|
push ds
|
|
push es
|
|
push fs
|
|
push gs
|
|
mov ax, 0x10
|
|
mov ds, ax
|
|
mov es, ax
|
|
mov fs, ax
|
|
mov gs, ax
|
|
mov eax, esp
|
|
push eax
|
|
mov eax, _irq_handler
|
|
call eax
|
|
pop eax
|
|
pop gs
|
|
pop fs
|
|
pop es
|
|
pop ds
|
|
popa
|
|
add esp, 8
|
|
iret
|
|
|
|
|
|
[global _read_cr0]
|
|
_read_cr0:
|
|
mov eax, cr0
|
|
retn
|
|
|
|
[global _write_cr0]
|
|
_write_cr0:
|
|
push ebp
|
|
mov ebp, esp
|
|
mov eax, [ebp+8]
|
|
mov cr0, eax
|
|
pop ebp
|
|
retn
|
|
|
|
[global _read_cr3]
|
|
_read_cr3:
|
|
mov eax, cr3
|
|
retn
|
|
|
|
[global _write_cr3]
|
|
_write_cr3:
|
|
push ebp
|
|
mov ebp, esp
|
|
mov eax, [ebp+8]
|
|
mov cr3, eax
|
|
pop ebp
|
|
retn
|
|
|
|
|
|
|
|
SECTION .bss
|
|
resb 8192 ; This reserves 8KBytes of memory here
|
|
_sys_stack: |