131 lines
2 KiB
ArmAsm
131 lines
2 KiB
ArmAsm
.code32
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.section multiboot
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#define MB_MAGIC 0x1BADB002
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#define MB_FLAGS 0x7
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#define MB_CHECKSUM -(MB_MAGIC + MB_FLAGS)
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.align 4
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.int MB_MAGIC
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.int MB_FLAGS
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.int MB_CHECKSUM
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.int 0,0,0,0,0
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.int 0
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.int 1024, 768, 32
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.section .text
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.extern init
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.global _start
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_start:
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finit
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mov $mb_ptr, %edi
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stosl
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mov %ebx, %eax
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stosl //Temponarily store both multiboot header pointer and multiboot
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mov $kernel_stack, %esp
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mov $0x80000001, %eax //Check if Long Mode is supported
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cpuid
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and $0x20000000, %edx
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jz x86_64_err
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xor %eax, %eax //Check if PAE is supported
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inc %eax
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cpuid
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and $0x40, %dl
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jz x86_64_err
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jmp x86_64_OK
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x86_64_err:
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cli
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hlt
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jmp x86_64_err
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x86_64_OK:
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//Fill one entry of both the pagemap L4 and the Pagedir PT
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mov $pmfill, %esi
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mov $pagemapL4, %edi
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lodsl
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stosl
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lodsl
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stosl
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mov $pagedirPT, %edi
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lodsl
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stosl
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lodsl
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stosl
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//Activate PAE
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mov %cr4, %eax
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or $0x20, %al
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mov %eax, %cr4
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//Activate x86_64
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mov $0xC0000080, %ecx
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rdmsr
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or $0x00000100, %eax
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wrmsr
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//Load Page Table
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mov $pagemapL4, %eax
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mov %eax, %cr3
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//Activate Paging
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mov %cr0, %eax
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bswap %eax
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or $0x80, %al
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bswap %eax
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mov %eax, %cr0
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//Jump to x86_64loader
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lgdt gdtr
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jmp $0x18, $start
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.code64
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//extern "C" void init(uint32_t eax, multiboot_info * ebx, uint64_t **** pt);
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.global init
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start:
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xor %rax, %rax
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mov $mb_ptr, %rsi
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lodsl
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mov %rax, %rdi
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lodsl
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mov %rax, %rsi
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mov $pagemapL4, %rdx
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call init
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stop:
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cli
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hlt
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jmp stop
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.section .data
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gdt:
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//NULL-descriptor
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.quad 0
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//32-bit code
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.word 0xFFFF
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.word 0x0000
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.byte 0x00
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.byte 0x98
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.byte 0xCF
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.byte 0x00
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//data
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.word 0xFFFF
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.word 0x0000
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.byte 0x00
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.byte 0x92
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.byte 0xCF
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.byte 00
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//64-bit code
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.int 0
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.byte 0
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.byte 0x98
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.byte 0x20
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.byte 0
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gdtr:
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.word 4 * 8
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.int gdt
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pmfill:
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.int pagedirPT + 0x7
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.int 0
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pdptfill:
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.quad 0x87
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.section .bss
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mb_ptr:
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// These 8 Bytes will never be used when the stack comes near it
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.space 4096
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kernel_stack:
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.align 4096
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pagemapL4:
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.space 4096
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pagedirPT:
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.space 4096
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