Jeremy Soller
272 lines
4.7 KiB
NASM
272 lines
4.7 KiB
NASM
struc Extent
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.block: resq 1,
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.length: resq 1
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endstruc
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struc Node
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.mode: resw 1
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.uid: resd 1
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.gid: resd 1
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.ctime: resq 1
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.ctime_nsec: resd 1
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.mtime: resq 1
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.mtime_nsec: resd 1
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.name: resb 222
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.parent: resq 1
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.next: resq 1
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.extents: resb Extent_size * 15
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endstruc
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struc Header
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; Signature, should be b"RedoxFS\0"
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.signature: resb 8
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; Version, should be 1
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.version: resq 1,
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; Disk ID, a 128-bit unique identifier
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.uuid: resb 16,
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; Disk size, in 512-byte sectors
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.size: resq 1,
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; Block of root node
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.root: resq 1,
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; Block of free space node
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.free: resq 1
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; Padding
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.padding: resb 456
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endstruc
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redoxfs:
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call redoxfs.open
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test eax, eax
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jz .good_header
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ret
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.good_header:
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mov eax, [.header + Header.root]
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mov bx, .dir
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call .node
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jmp redoxfs.root
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; node in eax, buffer in bx
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.node:
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add eax, (filesystem - boot) / 512
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mov cx, 1
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mov dx, 0
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call load
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call print_line
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ret
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align 512, db 0
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.header:
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times 512 db 0
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.dir:
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times 512 db 0
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.file:
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times 512 db 0
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redoxfs.open:
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mov eax, 0
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mov bx, redoxfs.header
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call redoxfs.node
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mov bx, 0
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.sig:
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mov al, [redoxfs.header + Header.signature + bx]
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mov ah, [.signature + bx]
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cmp al, ah
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jne .sig_err
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inc bx
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cmp bx, 8
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jl .sig
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mov bx, 0
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.ver:
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mov al, [redoxfs.header + Header.version + bx]
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mov ah, [.version + bx]
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cmp al, ah
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jne .ver_err
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inc bx
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jl .ver
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lea si, [redoxfs.header + Header.signature]
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call printrm
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call print_line
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xor ax, ax
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ret
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.err_msg: db "Failed to open RedoxFS: ",0
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.sig_err_msg: db "Signature error",13,10,0
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.ver_err_msg: db "Version error",13,10,0
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.sig_err:
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mov si, .err_msg
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call printrm
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mov si, .sig_err_msg
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call printrm
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mov ax, 1
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ret
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.ver_err:
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mov si, .err_msg
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call printrm
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mov si, .ver_err_msg
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call printrm
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mov ax, 1
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ret
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.signature: db "RedoxFS",0
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.version: dq 2
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redoxfs.root:
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lea si, [redoxfs.dir + Node.name]
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call printrm
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call print_line
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.lp:
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mov bx, 0
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.ext:
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mov eax, [redoxfs.dir + Node.extents + bx + Extent.block]
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test eax, eax
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jz .next
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mov ecx, [redoxfs.dir + Node.extents + bx + Extent.length]
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test ecx, ecx
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jz .next
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add ecx, 511
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shr ecx, 9
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push bx
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.ext_sec:
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push eax
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push ecx
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mov bx, redoxfs.file
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call redoxfs.node
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mov bx, 0
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.ext_sec_kernel:
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mov al, [redoxfs.file + Node.name + bx]
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mov ah, [.kernel_name + bx]
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cmp al, ah
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jne .ext_sec_kernel_break
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inc bx
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test ah, ah
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jnz .ext_sec_kernel
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pop ecx
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pop eax
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pop bx
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jmp redoxfs.kernel
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.ext_sec_kernel_break:
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pop ecx
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pop eax
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inc eax
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dec ecx
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jnz .ext_sec
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pop bx
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add bx, Extent_size
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cmp bx, Extent_size * 16
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jb .ext
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.next:
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mov eax, [redoxfs.dir + Node.next]
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test eax, eax
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jz .no_kernel
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mov bx, redoxfs.dir
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call redoxfs.node
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jmp .lp
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.no_kernel:
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mov si, .no_kernel_msg
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call printrm
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mov si, .kernel_name
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call printrm
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call print_line
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mov eax, 1
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ret
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.kernel_name: db "kernel",0
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.no_kernel_msg: db "Did not find: ",0
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redoxfs.kernel:
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lea si, [redoxfs.file + Node.name]
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call printrm
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call print_line
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mov edi, [kernel_base]
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.lp:
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mov bx, 0
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.ext:
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mov eax, [redoxfs.file + Node.extents + bx + Extent.block]
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test eax, eax
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jz .next
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mov ecx, [redoxfs.file + Node.extents + bx + Extent.length]
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test ecx, ecx
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jz .next
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push bx
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push eax
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push ecx
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push edi
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add eax, (filesystem - boot)/512
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add ecx, 511
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shr ecx, 9
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call load_extent
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pop edi
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pop ecx
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pop eax
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add edi, ecx
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pop bx
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add bx, Extent_size
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cmp bx, Extent_size * 16
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jb .ext
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.next:
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mov eax, [redoxfs.file + Node.next]
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test eax, eax
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jz .done
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push edi
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mov bx, redoxfs.file
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call redoxfs.node
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pop edi
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jmp .lp
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.done:
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sub edi, [kernel_base]
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mov [kernel_size], edi
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xor eax, eax
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ret
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