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mirror of https://github.com/xcat2/xNBA.git synced 2024-12-15 15:51:44 +00:00
xNBA/src/core/disk.c
2005-04-12 16:51:26 +00:00

290 lines
6.4 KiB
C

#include "etherboot.h"
#include "disk.h"
#warning "disk.c is currently broken"
#if 0
#undef disk_disable
static int dummy(void *unused __unused)
{
return (0);
}
static unsigned char disk_buffer[DISK_BUFFER_SIZE];
struct disk disk =
{
{
0, /* dev.disable */
{
0,
0,
PCI_BUS_TYPE,
}, /* dev.devid */
0, /* index */
0, /* type */
PROBE_FIRST, /* how_probe */
PROBE_NONE, /* to_probe */
0, /* failsafe */
0, /* type_index */
{}, /* state */
},
(int (*)(struct disk *, sector_t ))dummy, /* read */
0 - 1, /* drive */
0, /* hw_sector_size */
0, /* sectors_per_read */
0, /* bytes */
0, /* sectors */
0, /* sector */
disk_buffer, /* buffer */
0, /* priv */
0, /* disk_offset */
0, /* direction */
};
static int disk_read(
struct disk *disk, unsigned char *buffer, sector_t sector)
{
int result;
sector_t base_sector;
/* Note: I do not handle disk wrap around here! */
/* Compute the start of the track cache */
base_sector = sector;
/* Support sectors_per_read > 1 only on small disks */
if ((sizeof(sector_t) > sizeof(unsigned long)) &&
(disk->sectors_per_read > 1)) {
unsigned long offset;
offset = ((unsigned long)sector) % disk->sectors_per_read;
base_sector -= offset;
}
/* See if I need to update the track cache */
if ((sector < disk->sector) ||
sector >= disk->sector + (disk->bytes >> 9)) {
twiddle();
result = disk->read(disk, base_sector);
if (result < 0)
return result;
}
/* Service the request from the track cache */
memcpy(buffer, disk->buffer + ((sector - base_sector)<<9), SECTOR_SIZE);
return 0;
}
static int disk_read_sectors(
struct disk *disk,
unsigned char *buffer,
sector_t base_sector, unsigned int sectors)
{
sector_t sector = 0;
unsigned long offset;
int result = 0;
for(offset = 0; offset < sectors; offset++) {
sector = base_sector + offset;
if (sector >= disk->sectors) {
sector -= disk->sectors;
}
result = disk_read(disk, buffer + (offset << 9), sector);
if (result < 0)
break;
}
if (result < 0) {
printf("disk read error at 0x%lx\n", sector);
}
return result;
}
static os_download_t probe_buffer(unsigned char *buffer, unsigned int len,
int increment, unsigned int offset, unsigned int *roffset)
{
os_download_t os_download;
unsigned int end;
end = 0;
os_download = 0;
if (increment > 0) {
end = len - SECTOR_SIZE;
}
do {
offset += increment;
os_download = probe_image(buffer + offset, len - offset);
} while(!os_download && (offset != end));
*roffset = offset;
return os_download;
}
static int load_image(
struct disk *disk,
unsigned char *buffer, unsigned int buf_sectors,
sector_t block, unsigned int offset,
os_download_t os_download)
{
sector_t skip_sectors;
skip_sectors = 0;
while(1) {
skip_sectors = os_download(buffer + offset,
(buf_sectors << 9) - offset, 0);
block += skip_sectors + buf_sectors;
if (block >= disk->sectors) {
block -= disk->sectors;
}
offset = 0;
buf_sectors = 1;
if (disk_read_sectors(disk, buffer, block, 1) < 0) {
return 0;
}
}
return -1;
}
int disk_probe(struct dev *dev)
{
struct disk *disk = (struct disk *)dev;
if (dev->how_probe == PROBE_NEXT) {
disk->drive += 1;
}
return probe(dev);
}
int disk_load_configuration(struct dev *dev)
{
/* Start with the very simplest possible disk configuration */
struct disk *disk = (struct disk *)dev;
disk->direction = (dev->failsafe)?-1:1;
disk->disk_offset = 0;
return 0;
}
int disk_load(struct dev *dev)
{
struct disk *disk = (struct disk *)dev;
/* 16K == 8K in either direction from the start of the disk */
static unsigned char buffer[32*SECTOR_SIZE];
os_download_t os_download;
unsigned int offset;
unsigned int len;
unsigned int buf_sectors;
volatile sector_t block;
volatile int inc, increment;
int i;
int result;
jmp_buf real_restart;
printf("Searching for image...\n");
result = 0;
/* Only check for 16byte aligned images */
increment = (disk->direction < 0)?-16:16;
/* Load a buffer, and see if it contains the start of an image
* we can boot from disk.
*/
len = sizeof(buffer);
buf_sectors = sizeof(buffer) / SECTOR_SIZE;
inc = increment;
block = (disk->disk_offset) >> 9;
if (buf_sectors/2 > block) {
block = (disk->sectors - (buf_sectors/2)) + block;
}
/* let probe buffer assume offset always needs to be incremented */
offset = (len/2 + ((disk->disk_offset) & 0x1ff)) - inc;
/* Catch longjmp so if this image fails to load, I start looking
* for the next image where I left off looking for this image.
*/
memcpy(&real_restart, &restart_etherboot, sizeof(jmp_buf));
i = setjmp(restart_etherboot);
if ((i != 0) && (i != -2)) {
memcpy(&restart_etherboot, &real_restart, sizeof(jmp_buf));
longjmp(restart_etherboot, i);
}
/* Read the canidate sectors into the buffer */
if (disk_read_sectors(disk, buffer, block, buf_sectors) < 0) {
result = -1;
goto out;
}
if (inc == increment) {
os_download = probe_buffer(buffer, len, inc, offset, &offset);
if (os_download)
goto load_image;
inc = -inc;
}
os_download = probe_buffer(buffer, len, inc, offset, &offset);
if (!os_download) {
result = -1;
goto out;
}
load_image:
printf("Loading image...\n");
result = load_image(disk, buffer, buf_sectors, block, offset, os_download);
out:
memcpy(&restart_etherboot, &real_restart, sizeof(jmp_buf));
return result;
}
int url_file(const char *name,
int (*fnc)(unsigned char *, unsigned int, unsigned int, int) __unused)
{
unsigned int drive;
unsigned long disk_offset;
int direction;
int type;
disk_offset = 0;
direction = 1;
if (memcmp(name, "disk", 4) == 0) {
type = DISK_DRIVER;
name += 4;
}
else if (memcmp(name, "floppy", 6) == 0) {
type = FLOPPY_DRIVER;
name += 6;
}
else {
printf("Unknown device type\n");
return 0;
}
drive = strtoul(name, &name, 10);
if ((name[0] == '+') || (name[0] == '-')) {
direction = (name[0] == '-')? -1 : 1;
name++;
disk_offset = strtoul(name, &name, 10);
}
if (name[0]) {
printf("Junk '%s' at end of disk url\n", name);
return 0;
}
memset(&disk, 0, sizeof(disk));
disk.buffer = disk_buffer;
disk.drive = 0;
disk.dev.how_probe = PROBE_FIRST;
disk.dev.type = type;
do {
disk_disable();
disk.dev.how_probe = disk_probe(&disk.dev);
if (disk.dev.how_probe == PROBE_FAILED) {
printf("Not that many drives\n");
return 0;
}
} while(disk.drive < drive);
disk.direction = direction;
disk.disk_offset = disk_offset;
return disk_load(&disk.dev);
}
void disk_disable(void)
{
disable(&disk.dev);
}
#endif