binutils-gdb/sim/ppc/hw_disk.c

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1996-06-05 18:02:54 +02:00
/* This file is part of the program psim.
Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef _HW_DISK_C_
#define _HW_DISK_C_
#include "device_table.h"
#include "pk.h"
#include <stdio.h>
/* DEVICE
cdrom - readable block device
disk - readable block device that should be writeable
floppy - readable block device that should be writeable
DESCRIPTION
Block I/O devices that model the behavour of a fixed or removable
disk device.
Creating an instance of this device with no arguments will provide
access to primative read/write operators. If arguments are
specified then the disk-label package is used to perform abstract
disk I/O. The disk-label package will then use this devices
primatives.
For hardware I/O, this device would normally be attached to a
parent `bus' and that bus would use the I/O methods to read and
write raw data. The bus might actually be a SCSI or IDE device.
It is assumed that the parent bus can take care of DMA.
PROPERTIES
reg = <address> (required)
<address> is parent bus dependant.
device_type = "block"
name = "disk" | "cdrom" | "fd"
file = <file-name> (required)
The name of the file that contains the disk image.
*/
typedef struct _hw_disk_device {
const char *name;
int read_only;
unsigned_word size;
FILE *image;
} hw_disk_device;
typedef struct _hw_disk_instance {
long pos;
hw_disk_device *disk;
} hw_disk_instance;
static void
hw_disk_init_address(device *me)
{
hw_disk_device *disk = device_data(me);
generic_device_init_address(me);
if (disk->image != NULL)
fclose(disk->image);
disk->name = device_find_string_property(me, "file");
if (strcmp(device_name(me), "disk") == 0) {
disk->read_only = 0;
disk->image = fopen(disk->name, "r+");
}
else {
disk->read_only = 1;
disk->image = fopen(disk->name, "r");
}
if (disk->image == NULL) {
perror(device_name(me));
device_error(me, "open %s failed\n", disk->name);
}
}
static unsigned
hw_disk_io_read_buffer(device *me,
void *dest,
int space,
unsigned_word addr,
unsigned nr_bytes,
cpu *processor,
unsigned_word cia)
{
hw_disk_device *disk = device_data(me);
if (nr_bytes == 0)
return 0;
if (addr + nr_bytes > disk->size)
return 0;
if (fseek(disk->image, addr, SEEK_SET) < 0)
return 0;
if (fread(dest, nr_bytes, 1, disk->image) != 1)
return 0;
return nr_bytes;
}
static unsigned
hw_disk_io_write_buffer(device *me,
const void *source,
int space,
unsigned_word addr,
unsigned nr_bytes,
cpu *processor,
unsigned_word cia)
{
hw_disk_device *disk = device_data(me);
if (disk->read_only)
return 0;
if (nr_bytes == 0)
return 0;
if (addr + nr_bytes > disk->size)
return 0;
if (fseek(disk->image, addr, SEEK_SET) < 0)
return 0;
if (fwrite(source, nr_bytes, 1, disk->image) != 1)
return 0;
return nr_bytes;
}
/* instances of the hw_disk device */
static void
hw_disk_instance_delete(device_instance *instance)
{
hw_disk_instance *data = device_instance_data(instance);
zfree(data);
}
static int
hw_disk_instance_read(device_instance *instance,
void *buf,
unsigned_word len)
{
hw_disk_instance *data = device_instance_data(instance);
if (fseek(data->disk->image, data->pos, SEEK_SET) < 0)
return -1;
if (fread(buf, len, 1, data->disk->image) != 1)
return -1;
data->pos = ftell(data->disk->image);
return len;
}
static int
hw_disk_instance_write(device_instance *instance,
const void *buf,
unsigned_word len)
{
hw_disk_instance *data = device_instance_data(instance);
if (data->disk->read_only)
return -1;
if (fseek(data->disk->image, data->pos, SEEK_SET) < 0)
return -1;
if (fwrite(buf, len, 1, data->disk->image) != 1)
return -1;
data->pos = ftell(data->disk->image);
return len;
}
static int
hw_disk_instance_seek(device_instance *instance,
unsigned_word pos_hi,
unsigned_word pos_lo)
{
hw_disk_instance *data = device_instance_data(instance);
data->pos = pos_lo;
return 0;
}
static const device_instance_callbacks hw_disk_instance_callbacks = {
hw_disk_instance_delete,
hw_disk_instance_read,
hw_disk_instance_write,
hw_disk_instance_seek,
};
static device_instance *
hw_disk_create_instance(device *me,
const char *path,
const char *args)
{
device_instance *disk_instance;
hw_disk_device *disk = device_data(me);
hw_disk_instance *data = ZALLOC(hw_disk_instance);
data->disk = disk;
data->pos = 0;
disk_instance = device_create_instance_from(me, NULL,
data,
path, args,
&hw_disk_instance_callbacks);
return pk_disklabel_create_instance(disk_instance, args);
}
static device_callbacks const hw_disk_callbacks = {
{ hw_disk_init_address, NULL },
{ NULL, }, /* address */
{ hw_disk_io_read_buffer,
hw_disk_io_write_buffer, },
{ NULL, }, /* DMA */
{ NULL, }, /* interrupt */
{ NULL, }, /* unit */
hw_disk_create_instance,
};
static void *
hw_disk_create(const char *name,
const device_unit *unit_address,
const char *args,
device *parent)
{
/* create the descriptor */
hw_disk_device *hw_disk = ZALLOC(hw_disk_device);
return hw_disk;
}
const device_descriptor hw_disk_device_descriptor[] = {
{ "disk", hw_disk_create, &hw_disk_callbacks },
{ NULL },
};
#endif /* _HW_DISK_C_ */