From: Amelia Coutard Date: Wed, 4 May 2022 11:15:28 +0000 (+0200) Subject: Added a map to 64TiB of physical memory in the first 64TiB (half) of the higher half... X-Git-Url: https://git.ameliathe1st.gay/?a=commitdiff_plain;h=584f29189dd3ea49577a2159495abd1379c365d5;p=voyage-au-centre-des-fichiers.git Added a map to 64TiB of physical memory in the first 64TiB (half) of the higher half of memory --- diff --git a/src/boot.S b/src/boot.S index 98217be..e745a0f 100644 --- a/src/boot.S +++ b/src/boot.S @@ -76,14 +76,18 @@ TSS: IOPB: .short 0 TSS_END: .set TSS_SIZE, TSS_END - TSS +.align 0x1000 +PDPT_high: .skip 0x1000 - 16 + .quad 0x83 + .quad 0x83 + 1024 * 1024 * 1024 .section .bss .align 0x1000 PML4T: .skip 0x1000 PDPT_low: .skip 0x1000 -PDPT_high: .skip 0x1000 PDT: .skip 0x1000 PT: .skip 0x1000 +phys_mem_map: .skip 0x1000 * 128 - 8 .align 16 stack_bottom: .skip 1024 * 16 # 16KiB @@ -95,6 +99,12 @@ stack_top: _start: mov $stack_top - KERNEL_VMA, %esp + # Save multiboot info: + push $0 # / + push %eax # \ magic + push $0 # / + push %ebx # \ info structure + # Check if cpuid is supported: pushfl pop %eax @@ -108,15 +118,6 @@ _start: popfl xor %ecx, %eax jnz .has_cpuid - movw $0x024E, 0xB8000 - movw $0x026F, 0xB8002 - movw $0x0220, 0xB8004 - movw $0x0243, 0xB8006 - movw $0x0250, 0xB8008 - movw $0x0255, 0xB800A - movw $0x0249, 0xB800C - movw $0x0244, 0xB800E - movw $0x022E, 0xB8010 cli 1: hlt jmp 1b @@ -129,22 +130,14 @@ _start: jb .no_long_mode mov $0x80000001, %eax cpuid + # Long mode: test $1 << 29, %edx - jnz .has_long_mode + jz .no_long_mode + # 1GiB pages: + test $1 << 26, %edx + jz .no_long_mode + jmp .has_long_mode .no_long_mode: - movw $0x024E, 0xB8000 - movw $0x026F, 0xB8002 - movw $0x0220, 0xB8004 - movw $0x026C, 0xB8006 - movw $0x026F, 0xB8008 - movw $0x026E, 0xB800A - movw $0x0267, 0xB800C - movw $0x0220, 0xB800E - movw $0x026D, 0xB8010 - movw $0x026F, 0xB8012 - movw $0x0264, 0xB8014 - movw $0x0265, 0xB8016 - movw $0x022E, 0xB8018 cli 1: hlt jmp 1b @@ -164,7 +157,6 @@ _start: mov %eax, PML4T - KERNEL_VMA + 511 * 8 mov $PDT - KERNEL_VMA + 3, %eax mov %eax, PDPT_low - KERNEL_VMA + 0 * 8 - mov %eax, PDPT_high - KERNEL_VMA + 510 * 8 mov $PT - KERNEL_VMA + 3, %eax mov %eax, PDT - KERNEL_VMA + 0 * 8 @@ -211,16 +203,43 @@ _start: .code64 .trampoline: - mov %esp, %esp mov $GDT.KERNEL_DATA, %ax # Set the A-register to the data descriptor. mov %ax, %ds # Set the data segment to the A-register. mov %ax, %es # Set the extra segment to the A-register. mov %ax, %fs # Set the F-segment to the A-register. mov %ax, %gs # Set the G-segment to the A-register. mov %ax, %ss # Set the stack segment to the A-register. + mov $.higher_half, %rax jmp *%rax .section .text .higher_half: - call kmain + mov %esp, %esp + pop %r14 # Multiboot info address. + pop %r15 # Multiboot magic. + mov $stack_top, %rsp + + # map physical memory in kernel: + mov $phys_mem_map - KERNEL_VMA + 3, %rbx + mov $PML4T + 256 * 8, %rdi + mov $128, %rcx +1: mov %rbx, (%rdi) + add $0x1000, %rbx + add $8, %rdi + loop 1b + + mov $0x83, %rbx + mov $phys_mem_map, %rdi + mov $128 * 512, %rcx +1: mov %rbx, (%rdi) + add $1024 * 1024 * 1024, %rbx + add $8, %rdi + loop 1b + + mov $PML4T - KERNEL_VMA, %rax + mov %rax, %cr3 + + mov %r14, %rsi + mov %r15, %rdi + call kmain # With the two arguments popped earlier.