global _start
-extern print_str, print_dec, print_chr, clear_screen, paging
+extern print_str, print_dec, print_hex, print_chr, clear_screen, page_map, page_region
+
+%define GFXINFO 0x1000-10
section .data
headline: db "nyax stage3", 10, 10, 0
-disclaimer: db \
- "NyaX", 10, \
- "(C) 2022 Flecken-chan", 10, \
- "Dis progwam comes with ABSOLUTELY NO WAWWANTY", 10, \
- "Dis iz fwee software, and your'e welcome to redistwibute it", 10, " under certain conditions", 10, 0
+gfxregion:
+ .start: dq 0
+ .size: dq 0
+ .type: dw 2
+ dw 0
section .text
_start:
call clear_screen
- call paging
-
mov rdi, headline
call print_str
- mov rdi, disclaimer
- call print_str
+ call page_map
+
+ ;mov qword[rbx], -1
+
+ ;jmp $
+
+ movzx rax, word[GFXINFO+0]
+ movzx rbx, word[GFXINFO+4]
+ mov rcx, 4
+
+ xor rdx, rdx
+ mul rbx
+
+ xor rdx, rdx
+ mul rcx
+
+ xor rbx, rbx
+ mov ebx, [GFXINFO+6]
+
+ mov [gfxregion.start], rbx
+ mov [gfxregion.size], rax
+
+ mov r9, gfxregion
+ call page_region
+
+ mov rbx, [gfxregion.start]
+ mov rax, [gfxregion.size]
+
+ add rax, rbx
+
+.clear:
+ mov qword[rbx], -1
+ add rbx, 8
+ cmp rbx, rax
+ jb .clear
- xor rdi, rdi
-.loop:
- push rdi
- mov dil, 13
- call print_chr
- mov rdi, [rsp]
- call print_dec
- pop rdi
- inc rdi
- jmp .loop
+ jmp $
-global paging
+global page_map, page_region
extern print_hex, print_chr, newline, print_dec, print_str
-global paging
section .data
-pagebuf:
- .ptr: dq 0x5000
- .size: dq 0x3000
+dd 0
+
+pagebuf_init:
+ .start: dq 0x5000
+ .size: dq 0x2000
.used: dq 0
+pagebuf: dq pagebuf_init
+
+next_page: dq 0
+
section .text
+
+; allocate new page table buffer
alloc:
- mov rdi, .msg
- call print_str
- jmp $
-.msg: db "cock", 10, 0
+ ; rsi = buffer (result)
+ ; rdi = next_page
+ ; r8 = pagebuf
+ ; rbx = upper
+ ; rax = tmp; used_next
-tables:
-; level 4
+ mov r8, [pagebuf] ; *pagebuf
+ mov rsi, [r8] ; start = pagebuf->start
+
+ mov rbx, [r8+8] ; size = pagebuf->size
+ add rbx, rsi ; upper_have = start + size
+
+ ; round *up* to 0x1000 align
mov rax, 0xfff
- not rax ; offset mask
+ add rsi, rax
+ not rax
+ and rsi, rax ; aligned_start = (start + 0xfff) & (~0xfff)
- mov rbx, -1 ; low bits mask
- shl rbx, 3 ;
+ mov rax, [r8+16] ; used = pagebuf->used
+ add rax, 0x1000
+ add rsi, rax ; upper_need = aligned_start + used + 0x1000
- xor rcx, rcx
+ cmp rsi, rbx ; if upper_need > upper_have
+ ja .newbuf ; current region is full, get new
- mov r14, r10
- mov r13, r10
- mov r12, r10
- mov r11, r10
+ cmp rsi, r10 ; if upper_need >= next_page
+ jae .oom ; out of memory (target buffer isn't paged yet)
- not rcx ; negate remainder mask
- and r14, rcx ; apply remainder mask
- mov rcx, -1 ; reset remainder mask
- shl rcx, 12+9+9+9 ; update remainder mask
+ mov [r8+16], rax ; pagebuf->used = used + 0x1000
- shr r14, 12+9+9+9-3 ; divide
- and r14, rbx ; clear lower bits
+ ; clear out buffer
- mov rdx, 0x1000 ; offset
- and rdx, rax ; offset mask
- add r14, rdx ; add offset
+ mov rbx, rsi
+ sub rsi, 0x1000
- not rcx ; negate remainder mask
- and r13, rcx ; apply remainder mask
- mov rcx, -1 ; reset remainder mask
- shl rcx, 12+9+9 ; update remainder mask
+.clear:
+ sub rbx, 8
+ mov qword[rbx], 0
+ cmp rbx, rsi
+ jne .clear
- shr r13, 12+9+9-3 ; divide
- and r13, rbx ; clear lower bits
+ ret
- mov rdx, [r14] ; offset
- jnz .exist3
- call alloc
-.exist3:
- and rdx, rax ; offset mask
- add r13, rdx ; add offset
+; select next page buffer
+.newbuf:
+ cmp r8, pagebuf_init
+ jne .nextbuf
+ mov r8, 0x500
+ jmp .trybuf
- not rcx ; negate remainder mask
- and r12, rcx ; apply remainder mask
- mov rcx, -1 ; reset remainder mask
- shl rcx, 12+9 ; update remainder mask
+.nextbuf:
+ add r8, 24
- shr r12, 12+9-3 ; divide
- and r12, rbx ; clear lower bits
+.trybuf:
+ cmp qword[r8], 0
+ je .oom ; last region reached
- mov rdx, [r13] ; offset
- jnz .exist2
- call alloc
-.exist2:
- and rdx, rax ; offset mask
- add r12, rdx ; add offset
+ mov rax, [r8+16]
+
+ cmp rax, -1
+ je .nextbuf ; region is reserved
+
+ cmp rax, 0
+ jne .oom ; region has not been paged yet
+
+ mov [pagebuf], r8
+ jmp alloc
+
+.oom:
+ push rdi
+
+ mov rdi, .oom_msg
+ call print_str
+
+ pop rdi
+
+ call print_hex
+ call newline
+
+ jmp $
+
+.oom_msg: db "out of memory for page table", 10, "next_page = ", 0
+
+; get/create page tables
+get_tables:
+; level 4
+
+ ; rdi = address (arg, persist)
+ ; rax = tmp
+ ; rbx = mask
+ ; rcx = bits (persist)
+ ; rdx = level (persist)
+ ; r8 = table address
+ ; rsi = next offset (persist)
+
+ mov cl, 12+9*4
+ mov dl, 4
+ mov rsi, 0x1000
+
+; level 4
+.level:
+ dec dl
+ mov r8, rdi
+ mov rbx, -1 ; reset remainder mask
+ shl rbx, cl ; update remainder mask
+ not rbx ; negate remainder mask
+ and r8, rbx ; apply remainder mask
- not rcx ; negate remainder mask
- and r11, rcx ; apply remainder mask
+ mov al, 9
+ mul dl
+ add al, 12
+ mov cl, al
- mov rcx, -1 ; reset remainder mask
- shl rcx, 12 ; update remainder mask
+ shr r8, cl ; divide
+ shl r8, 3 ; multiply by 8
- shr r11, 12-3 ; divide
- and r11, rbx ; clear lower bits
+ mov rbx, 0xfff ; 0x1000 alignment
+ not rbx ; offset mask
+
+ and rsi, rbx ; apply offset mask
+ add r8, rsi ; add offset
+ push r8 ; store
+
+ cmp dl, 0
+ je .done
+
+ mov rsi, [r8] ; next offset
+ cmp rsi, 0
+ jne .level
- mov rdx, [r12] ; offset
- jnz .exist1
call alloc
-.exist1:
- and rdx, rax ; offset mask
- add r11, rdx ; add offset
+ or rsi, 3
+ mov r8, [rsp]
+ mov [r8], rsi
- ret
+ jmp .level
-; level1
- mov rax, r11
- xor rdx, rdx
- mov rbx, 8
- mul rbx
- mov r11, rax
- add r11, [r12]
- sub r11, 3
+.done:
+ pop r11
+ pop r12
+ pop r13
+ pop r14
ret
mov dil, ' '
jmp print_chr
-paging:
- mov r8, 0x0500 ; start of extended memory map
- movzx r9, word[0x1000-10-2] ; number of map entries
-
- mov r15, pagebuf
+page_region:
+ mov rdi, [r9] ; ptr = mmap_entry->ptr
+ mov r10, [next_page]
-.loop:
- ;mov r10, [r8]
- ;call tables
+ push rdi
- mov r10, 0xfffff
- call tables
+ mov rax, 1 << 63
- mov rdi, r14
+ or rdi, rax
call print_hex
call space
- mov rdi, r13
- call print_hex
- call space
+ mov rdi, [r9+8]
+ add rdi, [rsp]
+ or rdi, rax
- mov rdi, r12
call print_hex
- call space
+ call newline
- mov rdi, r11
- call print_hex
- call space
+ pop rdi
- mov rdi, [r11]
- call print_hex
+ ; for usable region (type = 1), set mmap_entry->used = 0
+ ; for reserved region (type = 2), set mmap_entry->used = -1
+ xor rax, rax
+ xor rbx, rbx
+ mov eax, dword[r9+16]
+ cmp rax, 1
+ je .set_used
+ dec rbx
+.set_used:
+ mov [r9+16], rbx
- jmp $
+ mov r10, rdi
+ mov r15, rdi ; r15 = end of region
+ add r15, [r9+8]
- mov rdi, r12
- call print_hex
- call space
+ mov rax, 0xfff
+ not rax
+ and rdi, rax ; round down to 0x1000 aligned
- mov rdi, r11
- call print_hex
- call space
+ cmp rdi, r10
+ jb .get_tables
- mov rdi, r10
- call print_hex
- call space
+ mov r10, rdi
+.get_tables:
+ call get_tables ; page tables into r11-r14
+ ; start filling L1 map
+.l1:
+ mov rax, rdi
+ or rax, 3
+ mov [r11], rax
- call newline
+ add rdi, 0x1000
- jmp $
+ cmp rdi, r10
+ jb .next
- ;jmp $
+ mov r10, rdi
- ;mov rcx, 1 << 63
- ;or rdi, rcx
- ;call print_hex
+.next:
+ cmp rdi, r15 ; if next >= end
+ jae .done
- ;mov dil, ' '
- ;call print_chr
+ ; prepare rcx mask for later
+ mov rcx, -1
+ shl rcx, 3
- ;mov rax, [rsp]
- ;mov rdi, [rax+8]
+ ; bump L1
- ;mov rcx, 1 << 63
- ;or rdi, rcx
- ;call print_hex
+ add r11, 8
+ mov rax, r11
+ and rax, 0xfff
+ jnz .l1
- ;mov dil, ' '
- ;call print_chr
+ ; bump L2
- ; mov rax, [rsp]
- ;xor rdi, rdi
- ;mov edi, [rax+16]
- ;call print_dec
+ add r12, 8
+ mov rax, r12
+ and rax, 0xfff
+ jnz .l2
- ;call newline
+ ; bump L3
- ;pop rax
- add r8, 24
+ add r13, 8
+ mov rax, r13
+ and rax, 0xfff
+ jnz .l3
+
+ ; bump L4
+
+ add r14, 8
+ mov rax, r14
+ and rax, 0xfff
+ jnz .l4
- ;pop rbx
+ ; machine has more than 256TB of RAM, tell user to fuck off
+ jmp .bruh
- dec r9
- jnz .loop
+.l4:
+ mov r13, [r14]
+ and r13, rcx
+ jnz .l3
+ call alloc
+ mov r13, rsi
+ or rsi, 3
+ mov [r14], rsi
+
+.l3:
+ mov r12, [r13]
+ and r12, rcx
+ jnz .l2
+
+ call alloc
+ mov r12, rsi
+ or rsi, 3
+ mov [r13], rsi
+
+.l2:
+ mov r11, [r12]
+ and r11, rcx
+ jnz .l2
+
+ call alloc
+ mov r11, rsi
+ or rsi, 3
+ mov [r12], rsi
+
+ jmp .l1
+
+.done:
+ mov [next_page], r10
+ ret
+
+.bruh:
+ mov rdi, .bruh_msg
+ call print_str
jmp $
+.bruh_msg: db "bruh why do you have more than 256TB of RAM (you fucking glow)", 10, 0
+
+; identity map available memory
+page_map:
+ mov r9, 0x0500 ; mmap_entry
+.entry:
+ cmp qword[r9], 0
+ je .done
+ call page_region
+ add r9, 24
+ jmp .entry
+.done:
ret
projects / nyax.git / commitdiff