6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2025-01-16 13:31:16 +00:00
Code Issues Projects Releases Wiki Activity

Merge pull request #129 from greg-king5/cbmdir

Browse Source 
Update 2 CBM directory functions.
This commit is contained in:
Oliver Schmidt 2014-07-17 16:50:49 +02:00
commit 6df42052b0
2 changed files with 18 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
libsrc/cbm/seekdir.c
View File

@ -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>
@ -15,8 +16,10 @@ void __fastcall__ seekdir (register DIR* dir, long offs)
unsigned char count;
unsigned char buf[128];
/* Make sure we have a reasonable value for offs */
if (offs > 0x1000) {
/* Make sure that we have a reasonable value for offs. We reject
** negative numbers by converting them to (very high) unsigned values.
*/
if ((unsigned long)offs > 0x1000uL) {
errno = EINVAL;
return;
}
@ -32,15 +35,15 @@ void __fastcall__ seekdir (register DIR* dir, long offs)
}
/* Skip until we've reached the target offset in the directory */
o = dir->off = offs;
o = dir->off = (unsigned)offs;
while (o) {
/* Determine size of next chunk to read */
if (o > sizeof (buf)) {
if (o > sizeof (buf)) {
count = sizeof (buf);
o -= sizeof (buf);
} else {
count = offs;
count = (unsigned char)o;
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);
;
@ -39,18 +40,14 @@
; Multiply first digit by 10
ldx #8
@L0: asl
asl tmp1
bcc @L1
clc
adc #10
@L1: dex
bne @L0
txa
asl a ; * 2
asl a ; * 4, carry cleared
adc tmp1 ; * 5
asl a ; * 10, carry cleared
; Add second digit to product
clc
adc tmp2
tax
@ -80,7 +77,8 @@ done: rts
.endproc
;--------------------------------------------------------------------------
; getdigit
; getdigit -- Converts PetSCII to binary.
; Sets carry if the character is outside of '0'-'9'.
.proc getdigit