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Merge pull request #129 from greg-king5/cbmdir

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Update 2 CBM directory functions.
This commit is contained in:
Oliver Schmidt
2014-07-17 16:50:49 +02:00
parent 30aab9a6b2 8324221360
commit 6df42052b0
2 changed files with 18 additions and 17 deletions
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15
libsrc/cbm/seekdir.c
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@@ -1,5 +1,6 @@
/* /*
** Ullrich von Bassewitz, 2012-06-03. Based on code by Groepaz. ** 2012-06-03, Ullrich von Bassewitz. Based on code by Groepaz.
** 2014-07-16, Greg King
*/ */
#include <fcntl.h> #include <fcntl.h>
@@ -15,8 +16,10 @@ void __fastcall__ seekdir (register DIR* dir, long offs)
unsigned char count; unsigned char count;
unsigned char buf[128]; unsigned char buf[128];
/* Make sure we have a reasonable value for offs */ /* Make sure that we have a reasonable value for offs. We reject
if (offs > 0x1000) { ** negative numbers by converting them to (very high) unsigned values.
*/
if ((unsigned long)offs > 0x1000uL) {
errno = EINVAL; errno = EINVAL;
return; return;
} }
@@ -32,15 +35,15 @@ void __fastcall__ seekdir (register DIR* dir, long offs)
} }
/* Skip until we've reached the target offset in the directory */ /* Skip until we've reached the target offset in the directory */
o = dir->off = offs; o = dir->off = (unsigned)offs;
while (o) { while (o) {
/* Determine size of next chunk to read */ /* Determine size of next chunk to read */
if (o > sizeof (buf)) { if (o > sizeof (buf)) {
count = sizeof (buf); count = sizeof (buf);
o -= sizeof (buf); o -= sizeof (buf);
} else { } else {
count = offs; count = (unsigned char)o;
o = 0; o = 0;
} }

20
libsrc/cbm/syschdir.s
View File

@@ -1,5 +1,6 @@
; ;
; Oliver Schmidt, 2012-10-16 ; 2012-10-16, Oliver Schmidt
; 2014-07-16, Greg King
; ;
; unsigned char __fastcall__ _syschdir (const char* name); ; unsigned char __fastcall__ _syschdir (const char* name);
; ;
@@ -39,18 +40,14 @@
; Multiply first digit by 10 ; Multiply first digit by 10
ldx #8 txa
@L0: asl asl a ; * 2
asl tmp1 asl a ; * 4, carry cleared
bcc @L1 adc tmp1 ; * 5
clc asl a ; * 10, carry cleared
adc #10
@L1: dex
bne @L0
; Add second digit to product ; Add second digit to product
clc
adc tmp2 adc tmp2
tax tax
@@ -80,7 +77,8 @@ done: rts
.endproc .endproc
;-------------------------------------------------------------------------- ;--------------------------------------------------------------------------
; getdigit ; getdigit -- Converts PetSCII to binary.
; Sets carry if the character is outside of '0'-'9'.
.proc getdigit .proc getdigit