dos33fsprogs/utils/prodos-utils/prodos_read.c

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#include <stdio.h>
#include <stdlib.h> /* exit() */
#include <string.h> /* strncpy() */
#include <sys/stat.h> /* struct stat */
#include <fcntl.h> /* O_RDONLY */
#include <unistd.h> /* lseek() */
#include <ctype.h> /* toupper() */
#include <errno.h>
#include "version.h"
#include "prodos.h"
extern int debug;
/* we want block 2 -> 0xb */
static int dos_interleave[16]= {
// 0,7,14,6,13,5,12,4,11,3,10,2,9,1,8,15,
0,14,13,12,11,10,9,8,7,6,5,4,3,2,1,15,
};
/* 0, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 15 */
/* ?? 0 7 14 6 13 5 12 4 11 3 10 2 9 1 8 15 */
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int prodos_read_block(struct voldir_t *voldir,
unsigned char *block, int blocknum) {
int result=0;
int track,sector1,sector2;
if (voldir->interleave==PRODOS_INTERLEAVE_PRODOS) {
/* Seek to VOLDIR */
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lseek(voldir->fd,voldir->image_offset+
blocknum*PRODOS_BYTES_PER_BLOCK,SEEK_SET);
result=read(voldir->fd,block,PRODOS_BYTES_PER_BLOCK);
if (result<PRODOS_BYTES_PER_BLOCK) {
fprintf(stderr,"Error reading block $%X\n",blocknum);
return -1;
}
}
else if (voldir->interleave==PRODOS_INTERLEAVE_DOS33) {
if (debug) printf("\tUsing DOS33 interleave, finding block $%X\n",blocknum);
track=(blocknum>>3);
sector1=dos_interleave[(blocknum&0x7)*2];
sector2=dos_interleave[(blocknum&0x7)*2+1];
if (debug) printf("\tRemapping block $%X to T%d S%d and T%d S%d\n",
blocknum,track,sector1,track,sector2);
if (debug) printf("\tSeeking to %x\n",((track<<4)+sector1)*256);
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lseek(voldir->fd,voldir->image_offset+
((track<<4)+sector1)*256,SEEK_SET);
result=read(voldir->fd,block,PRODOS_BYTES_PER_BLOCK/2);
if (result<PRODOS_BYTES_PER_BLOCK/2) {
fprintf(stderr,"Error reading block $%X (%X)\n",
blocknum,((track<<4)+sector1));
return -1;
}
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if (debug) printf("\tSeeking to %x\n",((track<<4)+sector2)*256);
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lseek(voldir->fd,voldir->image_offset+
((track<<4)+sector2)*256,SEEK_SET);
result=read(voldir->fd,block+256,PRODOS_BYTES_PER_BLOCK/2);
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if (result<PRODOS_BYTES_PER_BLOCK/2) {
fprintf(stderr,"Error reading block $%X (%X)\n",
blocknum,((track<<4)+sector2));
return -1;
}
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}
else {
fprintf(stderr,"ERROR! Unknown interleave!\n");
}
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return 0;
}
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int prodos_write_block(struct voldir_t *voldir,
unsigned char *block, int blocknum) {
int result=0;
int track,sector1,sector2;
if (voldir->interleave==PRODOS_INTERLEAVE_PRODOS) {
/* Seek to VOLDIR */
lseek(voldir->fd,voldir->image_offset+
blocknum*PRODOS_BYTES_PER_BLOCK,SEEK_SET);
result=write(voldir->fd,block,PRODOS_BYTES_PER_BLOCK);
if (result<PRODOS_BYTES_PER_BLOCK) {
fprintf(stderr,"Error writing block $%X\n",blocknum);
return -1;
}
}
else if (voldir->interleave==PRODOS_INTERLEAVE_DOS33) {
if (debug) printf("\tUsing DOS33 interleave, finding block $%X\n",blocknum);
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track=(blocknum>>3);
sector1=dos_interleave[(blocknum&0x7)*2];
sector2=dos_interleave[(blocknum&0x7)*2+1];
if (debug) printf("\tRemapping block $%X to T%d S%d and T%d S%d\n",
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blocknum,track,sector1,track,sector2);
if (debug) printf("\tSeeking to %x\n",((track<<4)+sector1)*256);
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lseek(voldir->fd,voldir->image_offset+
((track<<4)+sector1)*256,SEEK_SET);
result=write(voldir->fd,block,PRODOS_BYTES_PER_BLOCK/2);
if (result<PRODOS_BYTES_PER_BLOCK/2) {
fprintf(stderr,"Error writing block $%X (%X)\n",
blocknum,((track<<4)+sector1));
return -1;
}
if (debug) printf("\tSeeking to %x\n",((track<<4)+sector2)*256);
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lseek(voldir->fd,voldir->image_offset+
((track<<4)+sector2)*256,SEEK_SET);
result=write(voldir->fd,block+256,PRODOS_BYTES_PER_BLOCK/2);
if (result<PRODOS_BYTES_PER_BLOCK/2) {
fprintf(stderr,"Error writing block $%X (%X)\n",
blocknum,((track<<4)+sector2));
return -1;
}
}
else {
fprintf(stderr,"ERROR! Unknown interleave!\n");
}
return 0;
}