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Apple2: Rewrite readdir() and closedir() to assembly

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This commit is contained in:
Colin Leroy-Mira
2024-11-16 21:59:00 +01:00
committed by Oliver Schmidt
parent 700c01fa8b
commit f663ee428d
5 changed files with 202 additions and 197 deletions
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104
libsrc/apple2/opendir.s
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@@ -4,16 +4,18 @@
; DIR* __fastcall__ opendir (register const char* name)
;
.export _opendir
.export _opendir, read_dir_block_ptr1
.import closedir_ptr1
.import _open, _read, _close
.import _malloc, _free
.import _malloc
.import ___directerrno
.import ___oserror, __cwd
.import pushptr1, popptr1
.import pushax, pusha0
.import return0, returnFFFF
.importzp ptr1
@@ -37,7 +39,7 @@
sta ptr1
stx ptr1+1
: ; open directory
: ; Open directory
jsr pushptr1
lda #O_RDONLY
jsr pusha0
@@ -58,23 +60,17 @@
; We failed to allocate
pla ; Get fd back
ldx #$00
jsr _close ; close it
jsr _close ; Close it
lda #ENOMEM ; Set error
jsr ___directerrno
@return_null:
lda #$00
tax
rts
jmp return0
: ; Store dir struct to pointer
sta ptr1
stx ptr1+1
; Push ptr1, read will destroy it
jsr pushptr1
; Save fd to dir struct
lda #$00
ldy #DIR::FD + 1
@@ -84,49 +80,15 @@
pla ; Get fd back
sta (ptr1),y
jsr pusha0 ; push fd for read
lda #<DIR::BYTES
clc
adc ptr1
pha
lda #>DIR::BYTES
adc ptr1+1
tax
pla
jsr pushax ; Push dir->block.bytes for read
jsr read_dir_block_ptr1
bcc @read_ok
lda #<.sizeof(DIR::BYTES)
ldx #>.sizeof(DIR::BYTES)
jsr _read ; Read directory block
cpx #>.sizeof(DIR::BYTES)
bne @err_read
cmp #<.sizeof(DIR::BYTES)
beq @read_ok
@err_read:
; Read failed, exit
lda ___oserror
bne :+
lda #EINVAL
jsr ___directerrno
: ; Close fd
jsr popptr1 ; Restore our dir pointer
ldy #$00
lda (ptr1),y ; Get fd
ldx #$00
jsr _close
; Free dir structure
lda ptr1
ldx ptr1+1
jsr _free
jmp @return_null
; Close directory, free it
jsr closedir_ptr1
jmp return0 ; Return NULL
@read_ok:
; Read succeeded, populate dir struct
jsr popptr1 ; Restore our dir pointer
; Get file_count to entry_length from block
ldy #$26 + DIR::BYTES
@@ -153,3 +115,45 @@
ldx ptr1+1
rts
.endproc
; Read a directory for the DIR* pointer in ptr1
; Return with carry clear on success
read_dir_block_ptr1:
; Push ptr1, read will destroy it
jsr pushptr1
ldy #DIR::FD
lda (ptr1),y
jsr pusha0 ; Push fd for read
lda #<DIR::BYTES
clc
adc ptr1
pha
lda #>DIR::BYTES
adc ptr1+1
tax
pla
jsr pushax ; Push dir->block.bytes for read
lda #<.sizeof(DIR::BYTES)
ldx #>.sizeof(DIR::BYTES)
jsr _read ; Read directory block
cpx #>.sizeof(DIR::BYTES)
bne @read_err
cmp #<.sizeof(DIR::BYTES)
beq @read_ok
@read_err:
; Read failed, exit
lda ___oserror
bne :+
lda #EINVAL
jsr ___directerrno
: sec
bcs @out
@read_ok:
clc
@out:
jmp popptr1