Mark
70 lines
1.4 KiB
ArmAsm
70 lines
1.4 KiB
ArmAsm
.section .text
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.global boot_prepare_paging_32
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// Args: %ebp - return address
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// Return: %eax - physical PML4 address
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// Sets up paging directory
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boot_prepare_paging_32:
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.code32
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leal (kernel_pd_res - 0xFFFFFF0000000000), %edi
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movl %edi, %ebx
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movl $0x1800, %ecx
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xorl %eax, %eax
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cld
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rep stosl
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leal (boot_prepare_common - 0xFFFFFF0000000000), %edi
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jmp *%edi
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.global boot_prepare_paging_64
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boot_prepare_paging_64:
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.code64
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leaq kernel_pd_res(%rip), %rdi
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movq %rdi, %rbx
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movl $0x1800, %ecx
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xorl %eax, %eax
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cld
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rep stosl
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boot_prepare_common:
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// %ebx - kernel_pd_res
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.code32
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// Setup PDs
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movl %ebx, %edi
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xorl %ecx, %ecx
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1:
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// PD[i] = (i << 21) | write | present | huge
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movl %ecx, %edx
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shl $21, %edx
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orl $((1 << 7) | (1 << 0) | (1 << 1)), %edx
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movl %edx, (%edi, %ecx, 8)
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add $1, %ecx
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cmpl $(512 * 4), %ecx
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jne 1b
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// Setup PDPT
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addl $(4096 * 4), %edi
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xorl %ecx, %ecx
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2:
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// edi[ecx++] <- (ebx += 0x1000) | (1 << 0) | (1 << 1)
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movl %ebx, %edx
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orl $((1 << 0) | (1 << 1)), %edx
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movl %edx, (%edi, %ecx, 8)
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addl $0x1000, %ebx
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add $1, %ecx
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cmpl $4, %ecx
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jne 2b
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// Setup PML4
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// %edi - PDPT
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movl %edi, %ebx
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addl $0x1000, %edi
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orl $((1 << 0) | (1 << 1)), %ebx
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movl %ebx, (%edi)
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movl %ebx, 4080(%edi)
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mov %edi, %eax
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jmp *%ebp
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.code64
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