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56 lines
1.3 KiB
ArmAsm
56 lines
1.3 KiB
ArmAsm
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; Oliver Schmidt, 30.12.2004
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;
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; File descriptor management for the POSIX I/O routines
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;
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.include "errno.inc"
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.include "fcntl.inc"
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.include "filedes.inc"
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getfd:
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; Check for handle >= 256
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cpx #$00
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bne error
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; Check for handle >= MAX_FDS
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cmp #MAX_FDS
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bcs error
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; Convert handle to fdtab slot
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.assert .sizeof(FD) = 4, error
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asl
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asl
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; Check for fdtab slot in use
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tay
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lda fdtab + FD::REF_NUM,y
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beq error
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; Return success
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clc
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rts
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; Load errno code and return error
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error: lda #EINVAL
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sec
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rts
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.data
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fdtab: .assert .sizeof(FD) = 4, error
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.byte $80 ; STDIN_FILENO ::REF_NUM
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.byte O_RDONLY ; STDIN_FILENO ::FLAGS
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.addr $0000 ; STDIN_FILENO ::BUFFER
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.byte $80 ; STDOUT_FILENO::REF_NUM
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.byte O_WRONLY ; STDOUT_FILENO::FLAGS
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.addr $0000 ; STDOUT_FILENO::BUFFER
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.byte $80 ; STDERR_FILENO::REF_NUM
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.byte O_WRONLY ; STDERR_FILENO::FLAGS
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.addr $0000 ; STDERR_FILENO::BUFFER
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.res (MAX_FDS - 3) * .sizeof(FD)
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