qemu/hw/ds1225y.c

124 lines
3.5 KiB
C

/*
* QEMU NVRAM emulation for DS1225Y chip
*
* Copyright (c) 2007 Hervé Poussineau
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "hw.h"
#include "mips.h"
#include "nvram.h"
typedef enum
{
none = 0,
readmode,
writemode,
} nvram_open_mode;
struct ds1225y_t
{
target_phys_addr_t mem_base;
uint32_t capacity;
const char *filename;
QEMUFile *file;
nvram_open_mode open_mode;
};
static int ds1225y_set_to_mode(ds1225y_t *NVRAM, nvram_open_mode mode, const char *filemode)
{
if (NVRAM->open_mode != mode)
{
if (NVRAM->file)
qemu_fclose(NVRAM->file);
NVRAM->file = qemu_fopen(NVRAM->filename, filemode);
NVRAM->open_mode = mode;
}
return (NVRAM->file != NULL);
}
static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)
{
ds1225y_t *NVRAM = opaque;
int64_t pos;
pos = addr - NVRAM->mem_base;
if (addr >= NVRAM->capacity)
addr -= NVRAM->capacity;
if (!ds1225y_set_to_mode(NVRAM, readmode, "rb"))
return 0;
qemu_fseek(NVRAM->file, pos, SEEK_SET);
return (uint32_t)qemu_get_byte(NVRAM->file);
}
static void nvram_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)
{
ds1225y_t *NVRAM = opaque;
int64_t pos;
pos = addr - NVRAM->mem_base;
if (ds1225y_set_to_mode(NVRAM, writemode, "wb"))
{
qemu_fseek(NVRAM->file, pos, SEEK_SET);
qemu_put_byte(NVRAM->file, (int)value);
}
}
static CPUReadMemoryFunc *nvram_read[] = {
&nvram_readb,
NULL,
NULL,
};
static CPUWriteMemoryFunc *nvram_write[] = {
&nvram_writeb,
NULL,
NULL,
};
static CPUWriteMemoryFunc *nvram_none[] = {
NULL,
NULL,
NULL,
};
/* Initialisation routine */
ds1225y_t *ds1225y_init(target_phys_addr_t mem_base, const char *filename)
{
ds1225y_t *s;
int mem_index1, mem_index2;
s = qemu_mallocz(sizeof(ds1225y_t));
if (!s)
return NULL;
s->mem_base = mem_base;
s->capacity = 0x2000; /* Fixed for ds1225y chip: 8K */
s->filename = filename;
/* Read/write memory */
mem_index1 = cpu_register_io_memory(0, nvram_read, nvram_write, s);
cpu_register_physical_memory(mem_base, s->capacity, mem_index1);
/* Read-only memory */
mem_index2 = cpu_register_io_memory(0, nvram_read, nvram_none, s);
cpu_register_physical_memory(mem_base + s->capacity, s->capacity, mem_index2);
return s;
}