qemu/hw/ds1225y.c

181 lines
5.2 KiB
C

/*
* QEMU NVRAM emulation for DS1225Y chip
*
* Copyright (c) 2007-2008 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"
//#define DEBUG_NVRAM
typedef struct ds1225y_t
{
uint32_t chip_size;
QEMUFile *file;
uint8_t *contents;
uint8_t protection;
} ds1225y_t;
static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)
{
ds1225y_t *s = opaque;
uint32_t val;
val = s->contents[addr];
#ifdef DEBUG_NVRAM
printf("nvram: read 0x%x at " TARGET_FMT_lx "\n", val, addr);
#endif
return val;
}
static uint32_t nvram_readw (void *opaque, target_phys_addr_t addr)
{
uint32_t v;
v = nvram_readb(opaque, addr);
v |= nvram_readb(opaque, addr + 1) << 8;
return v;
}
static uint32_t nvram_readl (void *opaque, target_phys_addr_t addr)
{
uint32_t v;
v = nvram_readb(opaque, addr);
v |= nvram_readb(opaque, addr + 1) << 8;
v |= nvram_readb(opaque, addr + 2) << 16;
v |= nvram_readb(opaque, addr + 3) << 24;
return v;
}
static void nvram_writeb (void *opaque, target_phys_addr_t addr, uint32_t val)
{
ds1225y_t *s = opaque;
#ifdef DEBUG_NVRAM
printf("nvram: write 0x%x at " TARGET_FMT_lx "\n", val, addr);
#endif
s->contents[addr] = val & 0xff;
if (s->file) {
qemu_fseek(s->file, addr, SEEK_SET);
qemu_put_byte(s->file, (int)val);
qemu_fflush(s->file);
}
}
static void nvram_writew (void *opaque, target_phys_addr_t addr, uint32_t val)
{
nvram_writeb(opaque, addr, val & 0xff);
nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);
}
static void nvram_writel (void *opaque, target_phys_addr_t addr, uint32_t val)
{
nvram_writeb(opaque, addr, val & 0xff);
nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);
nvram_writeb(opaque, addr + 2, (val >> 16) & 0xff);
nvram_writeb(opaque, addr + 3, (val >> 24) & 0xff);
}
static void nvram_writeb_protected (void *opaque, target_phys_addr_t addr, uint32_t val)
{
ds1225y_t *s = opaque;
if (s->protection != 7) {
#ifdef DEBUG_NVRAM
printf("nvram: prevent write of 0x%x at " TARGET_FMT_lx "\n", val, addr);
#endif
return;
}
nvram_writeb(opaque, addr, val);
}
static void nvram_writew_protected (void *opaque, target_phys_addr_t addr, uint32_t val)
{
nvram_writeb_protected(opaque, addr, val & 0xff);
nvram_writeb_protected(opaque, addr + 1, (val >> 8) & 0xff);
}
static void nvram_writel_protected (void *opaque, target_phys_addr_t addr, uint32_t val)
{
nvram_writeb_protected(opaque, addr, val & 0xff);
nvram_writeb_protected(opaque, addr + 1, (val >> 8) & 0xff);
nvram_writeb_protected(opaque, addr + 2, (val >> 16) & 0xff);
nvram_writeb_protected(opaque, addr + 3, (val >> 24) & 0xff);
}
static CPUReadMemoryFunc * const nvram_read[] = {
&nvram_readb,
&nvram_readw,
&nvram_readl,
};
static CPUWriteMemoryFunc * const nvram_write[] = {
&nvram_writeb,
&nvram_writew,
&nvram_writel,
};
static CPUWriteMemoryFunc * const nvram_write_protected[] = {
&nvram_writeb_protected,
&nvram_writew_protected,
&nvram_writel_protected,
};
/* Initialisation routine */
void *ds1225y_init(target_phys_addr_t mem_base, const char *filename)
{
ds1225y_t *s;
int mem_indexRW, mem_indexRP;
QEMUFile *file;
s = qemu_mallocz(sizeof(ds1225y_t));
s->chip_size = 0x2000; /* Fixed for ds1225y chip: 8 KiB */
s->contents = qemu_mallocz(s->chip_size);
s->protection = 7;
/* Read current file */
file = qemu_fopen(filename, "rb");
if (file) {
/* Read nvram contents */
qemu_get_buffer(file, s->contents, s->chip_size);
qemu_fclose(file);
}
s->file = qemu_fopen(filename, "wb");
if (s->file) {
/* Write back contents, as 'wb' mode cleaned the file */
qemu_put_buffer(s->file, s->contents, s->chip_size);
qemu_fflush(s->file);
}
/* Read/write memory */
mem_indexRW = cpu_register_io_memory(nvram_read, nvram_write, s);
cpu_register_physical_memory(mem_base, s->chip_size, mem_indexRW);
/* Read/write protected memory */
mem_indexRP = cpu_register_io_memory(nvram_read, nvram_write_protected, s);
cpu_register_physical_memory(mem_base + s->chip_size, s->chip_size, mem_indexRP);
return s;
}