49 lines
1.1 KiB
NASM
49 lines
1.1 KiB
NASM
; RES resource routines
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; extract resource data from a RES binary loaded in memory
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; inputs:
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; r0: pointer to memory buffer containing a RES binary
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; r1: pointer to 3 character null-terminated resource ID string
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; r2: size of resource data to be extracted
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; outputs:
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; r0: pointer to newly-allocated memory buffer containing the requested resource data
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; this buffer must be freed by the caller!
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; returns zero if resource ID not found, not enough memory, or invalid magic bytes
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get_resource:
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cmp [r0], [res_magic]
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ifnz mov r0, 0
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ifnz ret
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push r3
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push r31
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mov r3, r0
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movz.8 r31, [r0+4]
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add r0, 5
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get_resource_find_loop:
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cmp [r0], [r1]
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ifz jmp get_resource_found
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add r0, 12
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loop get_resource_find_loop
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mov r0, 0
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jmp get_resource_end
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get_resource_found:
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cmp r2, [r0+8]
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ifgt mov r2, [r0+8]
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mov r31, [r0+4]
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add r31, r3
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mov r0, r2
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call allocate_memory
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cmp r0, 0
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ifz jmp get_resource_end
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mov r1, r0
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mov r0, r31
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call copy_memory_bytes
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mov r0, r1
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get_resource_end:
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pop r31
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pop r3
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ret
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res_magic: data.strz "RES"
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