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AK6DN.tu58em/file.c
Don North 3c387d5edd tu58 drive emulator
v1.4j
2015-06-08 10:23:59 -06:00

368 lines
7.9 KiB
C

//
// tu58 - Emulate a TU58 over a serial line
//
// Original (C) 1984 Dan Ts'o <Rockefeller Univ. Dept. of Neurobiology>
// Update (C) 2005-2012 Don North <ak6dn_at_mindspring_dot_com>
//
// This is the TU58 emulation program written at Rockefeller Univ., Dept. of
// Neurobiology. We copyright (C) it and permit its use provided it is not
// sold to others. Originally written by Dan Ts'o circa 1984 or so.
//
//
// TU58 File access routines
//
#include "common.h"
// file data structure
struct {
int32_t fd; // file descriptor
char *name; // file name
uint8_t rflag : 1; // read allowed
uint8_t wflag : 1; // write allowed
uint8_t cflag : 1; // create allowed
uint8_t iflag : 1; // init RT-11 structure
uint8_t xflag : 1; // init XXDP structure
} file [NTU58];
int32_t fpt; // number of active file descriptors
//
// init file structures for all units
//
void fileinit (void)
{
int32_t unit;
for (unit = 0; unit < NTU58; unit++) {
file[unit].fd = -1;
file[unit].name = NULL;
file[unit].rflag = 0;
file[unit].wflag = 0;
file[unit].cflag = 0;
file[unit].iflag = 0;
file[unit].xflag = 0;
}
fpt = 0;
return;
}
//
// close file structures for all units
//
void fileclose (void)
{
int32_t unit;
for (unit = 0; unit < NTU58; unit++) {
if (file[unit].fd != -1) {
close(file[unit].fd);
file[unit].fd = -1;
}
}
return;
}
//
// init RT-11 file directory structures (based on RT-11 v5.4)
//
static int32_t rt11_init (int32_t fd)
{
int32_t i;
static int16_t boot[] = { // offset 0000000
0000240, 0000005, 0000404, 0000000, 0000000, 0041420, 0116020, 0000400,
0004067, 0000044, 0000015, 0000000, 0005000, 0041077, 0047517, 0026524,
0026525, 0067516, 0061040, 0067557, 0020164, 0067157, 0073040, 0066157,
0066565, 0006545, 0005012, 0000200, 0105737, 0177564, 0100375, 0112037,
0177566, 0100372, 0000777
};
static int16_t bitmap[] = { // offset 0001000
0000000, 0170000, 0007777
};
static int16_t direct1[] = { // offset 0001700
0177777, 0000000, 0000000, 0000000, 0000000, 0000000, 0000000, 0000000,
0000000, 0000001, 0000006, 0107123, 0052122, 0030461, 0020101, 0020040,
0020040, 0020040, 0020040, 0020040, 0020040, 0020040, 0020040, 0020040,
0042504, 0051103, 0030524, 0040461, 0020040, 0020040
};
static int16_t direct2[] = { // offset 0006000
0000001, 0000000, 0000001, 0000000, 0000010, 0001000, 0000325, 0063471,
0023364, 0000770, 0000000, 0002264, 0004000
};
static struct {
int16_t *data;
int16_t length;
int32_t offset;
} table[] = {
{ boot, sizeof(boot), 00000 },
{ bitmap, sizeof(bitmap), 01000 },
{ direct1, sizeof(direct1), 01700 },
{ direct2, sizeof(direct2), 06000 },
{ NULL, 0, 0 }
};
// now write data from the table
for (i = 0; table[i].length; i++) {
lseek(fd, table[i].offset, SEEK_SET);
if (write(fd, table[i].data, table[i].length) != table[i].length) return -1;
}
return 0;
}
//
// init XXDP file directory structures (based on XXDPv2.5)
//
static int32_t xxdp_init (int32_t fd)
{
int32_t i;
static int16_t mfd1[] = { // MFD1
0000002, // ptr to MFD2
0000001, // interleave factor
0000007, // BITMAP start block number
0000007 // ptr to 1st BITMAP block
};
static int16_t mfd2[] = { // MFD2
0000000, // no more MFDs
0000401, // uic [1,1]
0000003, // ptr to 1st UFD block
0000011 // 9. words per UFD entry
};
static int16_t ufd1[] = { // UFD#1 (empty directory)
0000004 // ptr to UFD#2
};
static int16_t ufd2[] = { // UFD#2 (empty directory)
0000005 // ptr to UFD#3
};
static int16_t ufd3[] = { // UFD#3 (empty directory)
0000006 // ptr to UFD#4
};
static int16_t ufd4[] = { // UFD#4 (empty directory)
0000000 // no more UFDs
};
static int16_t map1[] = { // BITMAP#1
0000000, // no more BITMAPs
0000001, // map number
0000074, // 60. words per BITMAP
0000007, // ptr to BITMAP#1
0177777, // blocks 15..00 allocated
0177777, // blocks 31..16 allocated
0000377 // blocks 39..32 allocated
};
static struct {
int16_t *data;
int16_t length;
int32_t offset;
} table[] = {
{ mfd1, sizeof(mfd1), 01000 },
{ mfd2, sizeof(mfd2), 02000 },
{ ufd1, sizeof(ufd1), 03000 },
{ ufd2, sizeof(ufd2), 04000 },
{ ufd3, sizeof(ufd3), 05000 },
{ ufd4, sizeof(ufd4), 06000 },
{ map1, sizeof(map1), 07000 },
{ NULL, 0, 0 }
};
// now write data from the table
for (i = 0; table[i].length; i++) {
lseek(fd, table[i].offset, SEEK_SET);
if (write(fd, table[i].data, table[i].length) != table[i].length) return -1;
}
return 0;
}
//
// init a blank tape image (all zero)
//
static int32_t zero_init (int32_t fd)
{
int32_t i;
int8_t buf[BLOCKSIZE];
// zero a block
memset(buf, 0, sizeof(buf));
// zero a whole tape
lseek(fd, 0, SEEK_SET);
for (i = 0; i < TAPESIZE; i++)
if (write(fd, buf, sizeof(buf)) != sizeof(buf)) return -1;
return 0;
}
//
// open a file for a unit
//
int32_t fileopen (char *name,
int32_t mode)
{
int32_t fd;
// check if we can open any more units
if (fpt >= NTU58) { error("no more units available"); return -1; }
// save some data
file[fpt].name = name;
file[fpt].rflag = 1;
if (mode == FILEWRITE) file[fpt].wflag = 1;
if (mode == FILECREATE) file[fpt].wflag = file[fpt].cflag = 1;
if (mode == FILERT11INIT) file[fpt].wflag = file[fpt].cflag = file[fpt].iflag = 1;
if (mode == FILEXXDPINIT) file[fpt].wflag = file[fpt].cflag = file[fpt].xflag = 1;
// open file if it exists
if (file[fpt].wflag)
fd = open(file[fpt].name, O_BINARY|O_RDWR, 0666);
else
fd = open(file[fpt].name, O_BINARY|O_RDONLY);
// create file if it does not exist
if (fd < 0 && file[fpt].cflag) fd = creat(file[fpt].name, 0666);
if (fd < 0) { error("fileopen cannot open or create '%s'", file[fpt].name); return -2; }
// store opened file information
file[fpt].fd = fd;
// zap tape if requested
if (file[fpt].cflag) {
if (!zero_init(fd)) {
info("initialize tape on '%s'", file[fpt].name);
} else {
error("fileopen cannot init tape on '%s'", file[fpt].name);
return -3;
}
}
// initialize RT-11 directory structure ?
if (file[fpt].iflag) {
if (!rt11_init(fd)) {
info("initialize RT-11 directory on '%s'", file[fpt].name);
} else {
error("fileopen cannot init RT-11 filesystem on '%s'", file[fpt].name);
return -4;
}
}
// initialize XXDP directory structure ?
if (file[fpt].xflag) {
if (!xxdp_init(fd)) {
info("initialize XXDP directory on '%s'", file[fpt].name);
} else {
error("fileopen cannot init XXDP filesystem on '%s'", file[fpt].name);
return -5;
}
}
// output some info...
info("unit %d %c%c%c%c file '%s'",
fpt,
file[fpt].rflag ? 'r' : ' ',
file[fpt].wflag ? 'w' : ' ',
file[fpt].cflag ? 'c' : ' ',
file[fpt].iflag ? 'i' : file[fpt].xflag ? 'x' : ' ',
file[fpt].name);
fpt++;
return 0;
}
//
// check file unit OK
//
int32_t fileunit (int32_t unit)
{
if (unit < 0 || unit >= NTU58 || file[unit].fd == -1) {
error("bad unit %d", unit);
return -1;
}
return 0;
}
//
// seek file (tape) position
//
int32_t fileseek (int32_t unit,
int32_t size,
int32_t block,
int32_t offset)
{
if (fileunit(unit)) return -1;
if (block*size+offset > lseek(file[unit].fd, 0, SEEK_END)) return -2;
if (lseek(file[unit].fd, block*size+offset, SEEK_SET) < 0) return -3;
return 0;
}
//
// read bytes from the tape image file
//
int32_t fileread (int32_t unit,
uint8_t *buffer,
int32_t count)
{
if (fileunit(unit)) return -1;
if (!file[unit].rflag) return -2;
return read(file[unit].fd, buffer, count);
}
//
// write bytes to the tape image file
//
int32_t filewrite (int32_t unit,
uint8_t *buffer,
int32_t count)
{
if (fileunit(unit)) return -1;
if (!file[unit].wflag) return -2;
return write(file[unit].fd, buffer, count);
}
// the end