binutils-gdb/sim/ppc/hw_nvram.c

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/* 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_NVRAM_C_
#define _HW_NVRAM_C_
#ifndef STATIC_INLINE_HW_NVRAM
#define STATIC_INLINE_HW_NVRAM STATIC_INLINE
#endif
#include "device_table.h"
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#else
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#endif
/* DEVICE
nvram - non-volatile memory with clock
DESCRIPTION
This device implements a small byte addressable non-volatile
memory. The top 8 bytes of this memory include a real-time clock.
PROPERTIES
reg = <address> <size> (required)
Specify the address/size of this device within its parents address
space.
timezone = <integer> (optional)
Adjustment to the hosts current GMT (in seconds) that should be
applied when updating the NVRAM's clock. If no timezone is
specified, zero (GMT or UCT) is assumed.
*/
typedef struct _hw_nvram_device {
unsigned8 *memory;
unsigned sizeof_memory;
#ifdef HAVE_TIME_H
time_t host_time;
#else
long host_time;
#endif
unsigned timezone;
/* useful */
unsigned addr_year;
unsigned addr_month;
unsigned addr_date;
unsigned addr_day;
unsigned addr_hour;
unsigned addr_minutes;
unsigned addr_seconds;
unsigned addr_control;
} hw_nvram_device;
static void *
hw_nvram_create(const char *name,
const device_unit *unit_address,
const char *args)
{
hw_nvram_device *nvram = ZALLOC(hw_nvram_device);
return nvram;
}
typedef struct _hw_nvram_reg_spec {
unsigned32 base;
unsigned32 size;
} hw_nvram_reg_spec;
static void
hw_nvram_init_address(device *me)
{
hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);
/* use the generic init code to attach this device to its parent bus */
generic_device_init_address(me);
/* find the first non zero reg property and use that as the device
size */
if (nvram->sizeof_memory == 0) {
reg_property_spec reg;
int reg_nr;
for (reg_nr = 0;
device_find_reg_array_property(me, "reg", reg_nr, &reg);
reg_nr++) {
unsigned attach_size;
if (device_size_to_attach_size(device_parent(me),
&reg.size, &attach_size,
me)) {
nvram->sizeof_memory = attach_size;
break;
}
}
if (nvram->sizeof_memory == 0)
device_error(me, "reg property must contain a non-zero phys-addr:size tupple");
if (nvram->sizeof_memory < 8)
device_error(me, "NVRAM must be at least 8 bytes in size");
}
/* initialize the hw_nvram */
if (nvram->memory == NULL) {
nvram->memory = zalloc(nvram->sizeof_memory);
}
else
memset(nvram->memory, 0, nvram->sizeof_memory);
if (device_find_property(me, "timezone") == NULL)
nvram->timezone = 0;
else
nvram->timezone = device_find_integer_property(me, "timezone");
nvram->addr_year = nvram->sizeof_memory - 1;
nvram->addr_month = nvram->sizeof_memory - 2;
nvram->addr_date = nvram->sizeof_memory - 3;
nvram->addr_day = nvram->sizeof_memory - 4;
nvram->addr_hour = nvram->sizeof_memory - 5;
nvram->addr_minutes = nvram->sizeof_memory - 6;
nvram->addr_seconds = nvram->sizeof_memory - 7;
nvram->addr_control = nvram->sizeof_memory - 8;
}
static int
hw_nvram_bcd(int val)
{
val = val % 100;
if (val < 0)
val += 100;
return ((val / 10) << 4) + (val % 10);
}
/* If reached an update interval and allowed, update the clock within
the hw_nvram. While this function could be implemented using events
it isn't on the assumption that the HW_NVRAM will hardly ever be
referenced and hence there is little need in keeping the clock
continually up-to-date */
static void
hw_nvram_update_clock(hw_nvram_device *nvram,
cpu *processor)
{
#ifdef HAVE_TIME_H
if (!(nvram->memory[nvram->addr_control] & 0xc0)) {
time_t host_time = time(NULL);
if (nvram->host_time != host_time) {
time_t nvtime = host_time + nvram->timezone;
struct tm *clock = gmtime(&nvtime);
nvram->host_time = host_time;
nvram->memory[nvram->addr_year] = hw_nvram_bcd(clock->tm_year);
nvram->memory[nvram->addr_month] = hw_nvram_bcd(clock->tm_mon + 1);
nvram->memory[nvram->addr_date] = hw_nvram_bcd(clock->tm_mday);
nvram->memory[nvram->addr_day] = hw_nvram_bcd(clock->tm_wday + 1);
nvram->memory[nvram->addr_hour] = hw_nvram_bcd(clock->tm_hour);
nvram->memory[nvram->addr_minutes] = hw_nvram_bcd(clock->tm_min);
nvram->memory[nvram->addr_seconds] = hw_nvram_bcd(clock->tm_sec);
}
}
#else
error("fixme - where do I find out GMT\n");
#endif
}
static void
hw_nvram_set_clock(hw_nvram_device *nvram, cpu *processor)
{
error ("fixme - how do I set the localtime\n");
}
static unsigned
hw_nvram_io_read_buffer(device *me,
void *dest,
int space,
unsigned_word addr,
unsigned nr_bytes,
cpu *processor,
unsigned_word cia)
{
int i;
hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);
for (i = 0; i < nr_bytes; i++) {
unsigned address = (addr + i) % nvram->sizeof_memory;
unsigned8 data = nvram->memory[address];
hw_nvram_update_clock(nvram, processor);
((unsigned8*)dest)[i] = data;
}
return nr_bytes;
}
static unsigned
hw_nvram_io_write_buffer(device *me,
const void *source,
int space,
unsigned_word addr,
unsigned nr_bytes,
cpu *processor,
unsigned_word cia)
{
int i;
hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);
for (i = 0; i < nr_bytes; i++) {
unsigned address = (addr + i) % nvram->sizeof_memory;
unsigned8 data = ((unsigned8*)source)[i];
if (address == nvram->addr_control
&& (data & 0x80) == 0
&& (nvram->memory[address] & 0x80) == 0x80)
hw_nvram_set_clock(nvram, processor);
else
hw_nvram_update_clock(nvram, processor);
nvram->memory[address] = data;
}
return nr_bytes;
}
static device_callbacks const hw_nvram_callbacks = {
{ hw_nvram_init_address, },
{ NULL, }, /* address */
{ hw_nvram_io_read_buffer, hw_nvram_io_write_buffer }, /* IO */
};
const device_descriptor hw_nvram_device_descriptor[] = {
{ "nvram", hw_nvram_create, &hw_nvram_callbacks },
{ NULL },
};
#endif /* _HW_NVRAM_C_ */