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microwatt/simple_ram_behavioural_help...

259 lines
4.9 KiB
C

#include <stdio.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#define DEBUG
#define ALIGN_UP(VAL, SIZE) (((VAL) + ((SIZE)-1)) & ~((SIZE)-1))
#define vhpi0 2 /* forcing 0 */
#define vhpi1 3 /* forcing 1 */
struct int_bounds
{
int left;
int right;
char dir;
unsigned int len;
};
struct fat_pointer
{
void *base;
struct int_bounds *bounds;
};
static char *from_string(void *__p)
{
struct fat_pointer *p = __p;
unsigned long len = p->bounds->len;
char *m;
m = malloc(len+1);
if (!m) {
perror("malloc");
exit(1);
}
memcpy(m, p->base, len);
m[len] = 0x0;
return m;
}
static uint64_t from_std_logic_vector(unsigned char *p, unsigned long len)
{
unsigned long ret = 0;
if (len > 64) {
fprintf(stderr, "%s: invalid length %lu\n", __func__, len);
exit(1);
}
for (unsigned long i = 0; i < len; i++) {
unsigned char bit;
if (*p == vhpi0) {
bit = 0;
} else if (*p == vhpi1) {
bit = 1;
} else {
fprintf(stderr, "%s: bad bit %d\n", __func__, *p);
bit = 0;
}
ret = (ret << 1) | bit;
p++;
}
return ret;
}
static void to_std_logic_vector(unsigned long val, unsigned char *p,
unsigned long len)
{
if (len > 64) {
fprintf(stderr, "%s: invalid length %lu\n", __func__, len);
exit(1);
}
for (unsigned long i = 0; i < len; i++) {
if ((val >> (len-1-i) & 1))
*p = vhpi1;
else
*p = vhpi0;
p++;
}
}
#define MAX_REGIONS 128
struct ram_behavioural {
char *filename;
unsigned long size;
void *m;
};
static struct ram_behavioural behavioural_regions[MAX_REGIONS];
static unsigned long region_nr;
unsigned long behavioural_initialize(void *__f, unsigned long size)
{
struct ram_behavioural *r;
int fd;
struct stat buf;
unsigned long tmp_size;
void *mem;
if (region_nr == MAX_REGIONS) {
fprintf(stderr, "%s: too many regions, bump MAX_REGIONS\n");
exit(1);
}
r = &behavioural_regions[region_nr];
r->filename = from_string(__f);
r->size = ALIGN_UP(size, getpagesize());
fd = open(r->filename, O_RDWR);
if (fd == -1) {
fprintf(stderr, "%s: could not open %s\n", __func__,
r->filename);
exit(1);
}
if (fstat(fd, &buf)) {
perror("fstat");
exit(1);
}
/* XXX Do we need to truncate the underlying file? */
tmp_size = ALIGN_UP(buf.st_size, getpagesize());
if (r->size > tmp_size) {
void *m;
/*
* We have to pad the file. Allocate the total size, then
* create a space for the file.
*/
mem = mmap(NULL, r->size, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
if (mem == MAP_FAILED) {
perror("mmap");
exit(1);
}
if (tmp_size) {
munmap(mem, tmp_size);
m = mmap(mem, tmp_size, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED, fd, 0);
if (m == MAP_FAILED) {
perror("mmap");
exit(1);
}
if (m != mem) {
fprintf(stderr, "%s: mmap(MAP_FIXED) failed\n",
__func__);
exit(1);
}
}
} else {
mem = mmap(NULL, tmp_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
fd, 0);
if (mem == MAP_FAILED) {
perror("mmap");
exit(1);
}
}
behavioural_regions[region_nr].m = mem;
return region_nr++;
}
void behavioural_read(unsigned char *__val, unsigned char *__addr,
unsigned long sel, int identifier)
{
struct ram_behavioural *r;
unsigned long val = 0;
unsigned long addr = from_std_logic_vector(__addr, 64);
unsigned char *p;
if (identifier > region_nr) {
fprintf(stderr, "%s: bad index %d\n", __func__, identifier);
exit(1);
}
r = &behavioural_regions[identifier];
for (unsigned long i = 0; i < 8; i++) {
#if 0
/* sel only used on writes */
if (!(sel & (1UL << i)))
continue;
#endif
if ((addr + i) > r->size) {
fprintf(stderr, "%s: bad memory access %lx %lx\n", __func__,
addr+i, r->size);
exit(1);
}
p = (unsigned char *)(((unsigned long)r->m) + addr + i);
val |= (((unsigned long)*p) << (i*8));
}
#ifdef DEBUG
printf("MEM behave %d read %016lx addr %016lx sel %02lx\n", identifier, val,
addr, sel);
#endif
to_std_logic_vector(val, __val, 64);
}
void behavioural_write(unsigned char *__val, unsigned char *__addr,
unsigned int sel, int identifier)
{
struct ram_behavioural *r;
unsigned long val = from_std_logic_vector(__val, 64);
unsigned long addr = from_std_logic_vector(__addr, 64);
unsigned char *p;
if (identifier > region_nr) {
fprintf(stderr, "%s: bad index %d\n", __func__, identifier);
exit(1);
}
r = &behavioural_regions[identifier];
p = (unsigned char *)(((unsigned long)r->m) + addr);
#ifdef DEBUG
printf("MEM behave %d write %016lx addr %016lx sel %02x\n", identifier, val,
addr, sel);
#endif
for (unsigned long i = 0; i < 8; i++) {
if (!(sel & (1UL << i)))
continue;
if ((addr + i) > r->size) {
fprintf(stderr, "%s: bad memory access %lx %lx\n", __func__,
addr+i, r->size);
exit(1);
}
p = (unsigned char *)(((unsigned long)r->m) + addr + i);
*p = (val >> (i*8)) & 0xff;
}
}