Utilities to work with Fomu, as attached to a Raspberry Pi
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fomu-flash/ice40.c

562 lines
18 KiB

#include <assert.h>
#include <string.h>
#include "ice40.h"
#define MAX(x, y) (x) > (y) ? (x) : (y)
#define ARRAY_SIZE(x) ((sizeof(x) / sizeof(*x)))
#define DEBUG_PRINT(...)
// #define DEBUG_PRINT(...) printf(__VA_ARGS__)
// #define SCAN_DEBUG
// Make this a macro so line numbers work correctly
#define assert_words_equal(check_word, old_word) \
if (check_word != old_word) { \
int j; \
printf("mismatch in source stream!\n"); \
printf("old_word: %04x check_word: %04x\n", old_word, check_word); \
printf("rand:"); \
for (j = (offset + mapping) - 16; j < (offset + mapping) + 16; j++) { \
if (j == (offset + mapping)) \
printf(" [%04x]", ora16[j]); \
else \
printf(" %04x", ora16[j]); \
}\
printf("\n"); \
\
printf(" rom:");\
for (j = i - 16; j < i + 16; j++) {\
printf(" %04x", oro16[j]);\
}\
printf("\n");\
printf("if possible, please email the rom and bitstream to sean@xobs.io\n"); \
} \
assert(check_word == old_word)
#ifdef SCAN_DEBUG
#define SCAN_DEBUG_PRINT(...) printf(__VA_ARGS__)
#else
#define SCAN_DEBUG_PRINT(...)
#endif
struct Ice40Bitstream
{
uint32_t offset;
uint32_t current_bank;
uint32_t current_width;
uint32_t current_height;
uint32_t current_offset;
uint32_t cram_width;
uint32_t cram_height;
uint32_t bram_width;
uint32_t bram_height;
uint16_t crc_value;
uint8_t warmboot;
uint8_t nosleep;
uint8_t frequency_range;
};
static void update_crc16(uint16_t *crc, uint8_t byte)
{
// CRC-16-CCITT, Initialize to 0xFFFF, No zero padding
for (int i = 7; i >= 0; i--)
{
uint16_t xor_value = ((*crc >> 15) ^ ((byte >> i) & 1)) ? 0x1021 : 0;
*crc = (*crc << 1) ^ xor_value;
}
}
static uint32_t get_bit_offset(int x, int total_bits) {
// return (8192 * (x & 7)) + (x >> 3);
int bitshift = ffs(total_bits)-1;
return ((x * 8192) % total_bits) + ((x*8192) >> bitshift);
}
uint32_t xorshift32(uint32_t x)
{
/* Algorithm "xor" from p. 4 of Marsaglia, "Xorshift RNGs" */
x = x ^ (x << 13);
x = x ^ (x >> 17);
x = x ^ (x << 5);
return x;
}
uint32_t get_rand(uint32_t x) {
uint32_t out = 0;
int i;
for (i = 0; i < 32; i++) {
x = xorshift32(x);
if ((x & 1) == 1)
out = out | (1 << i);
}
return out;
}
static uint32_t fill_rand(uint32_t *bfr, int count) {
int i;
uint32_t last = 1;
for (i = 0; i < count / 4; i++) {
last = get_rand(last);
bfr[i] = last;
}
return i;
}
uint32_t swap_u32(uint32_t word) {
return (((word >> 24) & 0x000000ff)
| ((word >> 8) & 0x0000ff00)
| ((word << 8) & 0x00ff0000)
| ((word << 24) & 0xff000000));
}
struct irw_file *irw_open(const char *filename, const char *mode)
{
struct irw_file *f = malloc(sizeof(*f));
memset(f, 0, sizeof(*f));
f->f = fopen(filename, mode);
return f;
}
struct irw_file *irw_open_fake(void *hook_data,
int (*read_hook)(void *data),
int (*write_hook)(void *data, uint8_t b)) {
struct irw_file *f = malloc(sizeof(*f));
memset(f, 0, sizeof(*f));
f->read_hook = read_hook;
f->write_hook = write_hook;
f->hook_data = hook_data;
return f;
}
int irw_readb(struct irw_file *f)
{
int val;
if (f->read_hook)
val = f->read_hook(f->hook_data);
else
val = fgetc(f->f);
if (val == EOF)
return EOF;
update_crc16(&f->crc, val);
return val;
}
int irw_writeb(struct irw_file *f, int c) {
update_crc16(&f->crc, c);
if (f->write_hook)
return f->write_hook(f->hook_data, c);
else
return fputc(c, f->f);
}
void irw_close(struct irw_file **f) {
if (!f)
return;
if (!*f)
return;
if (!(*f)->f)
return;
fclose((*f)->f);
*f = NULL;
}
uint8_t get_bit(uint32_t *field, uint32_t offset)
{
// printf("offset&31: %d\n", offset & 31);
// printf("offset/sizeof(*field): %d\n", offset >> 5);
assert(offset < 65536);
return !!(field[offset >> 5] & (1 << (offset & 31)));
}
void set_bit(uint32_t *field, uint32_t offset)
{
assert(offset < 65536);
field[offset >> 5] |= (1 << (offset & 31));
}
void clear_bit(uint32_t *field, uint32_t offset)
{
assert(offset < 65536);
field[offset >> 5] &= ~(1 << (offset & 31));
}
int ice40_patch(struct irw_file *f, struct irw_file *rom,
struct irw_file *o, uint32_t byte_count)
{
uint32_t preamble = 0;
uint8_t wakeup = 0;
struct Ice40Bitstream bs;
uint32_t input_rom[byte_count / sizeof(uint32_t)];
uint32_t input_rand[byte_count / sizeof(uint32_t)];
uint32_t output_rand[byte_count / sizeof(uint32_t)];
uint32_t output_rom[byte_count / sizeof(uint32_t)];
uint8_t *i8 = (uint8_t *)input_rom;
uint16_t *ora16 = (uint16_t *)output_rand;
uint16_t *oro16 = (uint16_t *)output_rom;
unsigned int ora_ptr = 0;
unsigned int input_ptr;
int b;
int errors = 0;
memset(&bs, 0, sizeof(bs));
// Read the ROM into a source buffer
memset(input_rom, 0, sizeof(input_rom));
input_ptr = 0;
while ((b = irw_readb(rom)) != EOF)
i8[input_ptr++] = b;
DEBUG_PRINT("read %d bytes from rom\n", input_ptr);
// Generate our reference pattern
memset(input_rand, 0, sizeof(input_rand));
fill_rand(input_rand, sizeof(input_rand));
// Swap either the input or output data, as necessary
for (input_ptr = 0; input_ptr < sizeof(input_rom)/4; input_ptr++) {
// input_rand[input_ptr] = swap_u32(input_rand[input_ptr]);
// input_rom[input_ptr] = swap_u32(input_rom[input_ptr]);
}
// Spray the reference pattern and ROM like they would exist in the FPGA
for (input_ptr = 0; input_ptr < sizeof(input_rom) * 8; input_ptr++) {
int bit;
bit = get_bit(input_rand, get_bit_offset(input_ptr, sizeof(input_rand)*8));
if (bit)
set_bit(output_rand, input_ptr);
else
clear_bit(output_rand, input_ptr);
bit = get_bit(input_rom, get_bit_offset(input_ptr, sizeof(input_rom)*8));
if (bit)
set_bit(output_rom, input_ptr);
else
clear_bit(output_rom, input_ptr);
}
while (1)
{
b = irw_readb(f);
if (b == EOF)
break;
irw_writeb(o, b);
preamble = (preamble << 8) | b;
if (preamble == 0x7eaa997e)
{
// DEBUG_PRINT("found preamble at %d\n", bs.offset);
break;
}
}
while (!wakeup)
{
int b = irw_readb(f);
if (b == EOF)
{
// DEBUG_PRINT("reached end of file\n");
break;
}
irw_writeb(o, b);
uint8_t cmd = b >> 4;
uint8_t payload_len = b & 0xf;
uint32_t payload = 0;
uint8_t last0, last1;
unsigned int i;
for (i = 0; i < payload_len; i++)
{
b = irw_readb(f);
payload = (payload << 8) | (b & 0xff);
// Don't write the CRC16 out, since we'll do that later on.
if (cmd != 2)
irw_writeb(o, b);
}
switch (cmd)
{
case 0:
switch (payload)
{
case 1:
DEBUG_PRINT("CRAM data (bank %d): %d x %d @ 0x%08x; %d bits = %d bytes\n",
bs.current_bank,
bs.current_width,
bs.current_height,
bs.current_offset,
bs.current_width * bs.current_height,
(bs.current_width * bs.current_height) / 8);
bs.cram_width = MAX(bs.cram_width, bs.current_width);
bs.cram_height = MAX(bs.cram_height, bs.current_height);
for (i = 0; i < ((bs.current_width * bs.current_height) / 8); i++)
{
irw_writeb(o, irw_readb(f));
}
last0 = irw_readb(f);
last1 = irw_readb(f);
if (last0 || last1)
{
printf("expected 0x0000 after CRAM data, got %02x %02x\n", last0, last1);
}
irw_writeb(o, last0);
irw_writeb(o, last1);
break;
case 3:
DEBUG_PRINT("BRAM data (bank %d): %d x %d @ 0x%08x; %d bits = %d bytes\n",
bs.current_bank,
bs.current_width,
bs.current_height,
bs.current_offset,
bs.current_width * bs.current_height,
(bs.current_width * bs.current_height) / 8);
bs.bram_width = MAX(bs.bram_width, bs.current_width);
bs.bram_height = MAX(bs.bram_height, bs.current_height);
ora_ptr = 16 * bs.current_offset;
// Step 1: Find a mapping by scanning through the first 128 words looking for patterns.
uint16_t scan_buffer[128];
assert(((bs.current_width * bs.current_height)/8)*2 > 128);
for (i = 0; i < ARRAY_SIZE(scan_buffer); i++) {
scan_buffer[i] = ((irw_readb(f) << 8) & 0xff00) | ((irw_readb(f) << 0) & 0x00ff);
}
#ifdef SCAN_DEBUG
SCAN_DEBUG_PRINT("scan:");
for (i = 0; i < ARRAY_SIZE(scan_buffer); i++) {
SCAN_DEBUG_PRINT(" %04x", scan_buffer[i]);
}
SCAN_DEBUG_PRINT("\n");
SCAN_DEBUG_PRINT("rand:");
for (i = 0; i < ARRAY_SIZE(scan_buffer); i++) {
SCAN_DEBUG_PRINT(" %04x", ora16[ora_ptr + i]);
}
SCAN_DEBUG_PRINT("\n");
SCAN_DEBUG_PRINT(" rom:");
for (i = 0; i < ARRAY_SIZE(scan_buffer); i++) {
SCAN_DEBUG_PRINT(" %04x", oro16[ora_ptr + i]);
}
SCAN_DEBUG_PRINT("\n");
#endif /* SCAN_DEBUG */
int outer_word = 0;
static struct {
int bitstream;
int random;
int stride;
} word_mappings[16];
int word_stride = -1;
for (outer_word = 0; outer_word < 16; outer_word++) {
int inner_word;
word_mappings[outer_word].bitstream = -1;
word_mappings[outer_word].random = -1;
word_mappings[outer_word].stride = -1;
for (inner_word = 0; inner_word < 16; inner_word++) {
// We have a candidate offset. Figure out what its stride is,
// and validate that we have multiple matches.
if (scan_buffer[outer_word] == ora16[ora_ptr + inner_word]) {
SCAN_DEBUG_PRINT("Candidate %04x @ %d/%d\n", scan_buffer[outer_word], outer_word, inner_word);
int scan_offset = 0;
for (scan_offset = 0; scan_offset < 30; scan_offset++) {
if ((scan_buffer[outer_word + scan_offset] == ora16[ora_ptr + inner_word + 16])
&& (scan_buffer[outer_word + (scan_offset*2)] == ora16[ora_ptr + inner_word + 32])) {
SCAN_DEBUG_PRINT("Scan offset: %d\n", scan_offset);
word_mappings[outer_word].bitstream = outer_word;
word_mappings[outer_word].random = inner_word;
word_mappings[outer_word].stride = scan_offset;
}
}
}
}
}
for (i = 0; i < ARRAY_SIZE(word_mappings); i++) {
if (word_mappings[i].stride != -1) {
if (word_stride != -1) {
if (word_mappings[i].stride != word_stride) {
printf("This stride is different (%d vs expected %d)\n", word_mappings[i].stride, word_stride);
}
}
word_stride = word_mappings[i].stride;
}
}
#ifdef SCAN_DEBUG
for (outer_word = 0; outer_word < ARRAY_SIZE(word_mappings); outer_word++) {
SCAN_DEBUG_PRINT("word_mappings[%2d]: bitstream: %2d random: %2d stride: %2d\n",
outer_word, word_mappings[outer_word].bitstream,
word_mappings[outer_word].random, word_mappings[outer_word].stride);
}
#endif /* SCAN_DEBUG */
for (i = 0; i < ARRAY_SIZE(scan_buffer); i++) {
int offset = -1;
int mapping = -1;
if (word_stride != -1) {
offset = (i / word_stride) * 16;
mapping = word_mappings[i % word_stride].random;
}
uint16_t old_word = scan_buffer[i];
uint16_t check_word;
uint16_t new_word;
if (mapping == -1) {
new_word = check_word = old_word;
}
else {
check_word = ora16[ora_ptr + offset + mapping];
new_word = oro16[ora_ptr + offset + mapping];
}
irw_writeb(o, new_word >> 8);
irw_writeb(o, new_word);
SCAN_DEBUG_PRINT("%4d %4d %2d %2d %04x <-> %04x -> %04x\n", i, sizeof(scan_buffer), offset, mapping, old_word, check_word, new_word);
assert_words_equal(check_word, old_word);
}
SCAN_DEBUG_PRINT("---\n");
// Finish reading the page
for (i = ARRAY_SIZE(scan_buffer); i < ((bs.current_width * bs.current_height) / 8)/2; i++) {
int offset = -1;
int mapping = -1;
if (word_stride != -1) {
offset = (i / word_stride) * 16;
mapping = word_mappings[i % word_stride].random;
}
uint16_t old_word =
((irw_readb(f) << 8) & 0xff00)
|
((irw_readb(f) << 0) & 0x00ff)
;
uint16_t check_word;
uint16_t new_word;
if (mapping == -1) {
new_word = check_word = old_word;
}
else {
check_word = ora16[ora_ptr + offset + mapping];
new_word = oro16[ora_ptr + offset + mapping];
}
irw_writeb(o, new_word >> 8);
irw_writeb(o, new_word);
SCAN_DEBUG_PRINT("%4d %4d %2d %2d %04x <-> %04x -> %04x\n", i, sizeof(scan_buffer), offset, mapping, old_word, check_word, new_word);
assert_words_equal(check_word, old_word);
}
last0 = irw_readb(f);
last1 = irw_readb(f);
if (last0 || last1)
{
printf("expected 0x0000 after BRAM data, got %02x %02x\n", last0, last1);
}
irw_writeb(o, last0);
irw_writeb(o, last1);
break;
// Reset CRC
case 5:
f->crc = 0xffff;
o->crc = 0xffff;
break;
// Wakeup
case 6:
wakeup = 1;
break;
default:
printf("unrecognized command 0x%02x 0x%02x\n", cmd, payload);
break;
}
break;
// Set current bank
case 1:
bs.current_bank = payload;
ora_ptr = 0;
// printf("setting bank number to %d\n", bs.current_bank);
break;
// Validate CRC16
case 2:
DEBUG_PRINT("crc check (%04x == %04x)\n", f->crc, 0);
uint16_t crc16 = o->crc;
irw_writeb(o, crc16 >> 8);
irw_writeb(o, crc16);
break;
// Set frequency range
case 5:
switch (payload)
{
case 0:
bs.frequency_range = 0;
break;
case 1:
bs.frequency_range = 1;
break;
case 2:
bs.frequency_range = 2;
break;
default:
printf("unknown frequency range payload: %02x\n", payload);
break;
}
break;
// Set current width
case 6:
bs.current_width = payload + 1;
break;
// Set current height
case 7:
bs.current_height = payload;
break;
// Set current ofset
case 8:
bs.current_offset = payload;
break;
// Set flags
case 9:
switch (payload)
{
case 0:
bs.warmboot = 0;
bs.nosleep = 0;
break;
case 1:
bs.warmboot = 0;
bs.nosleep = 1;
break;
case 32:
bs.warmboot = 1;
bs.nosleep = 0;
break;
case 33:
bs.warmboot = 1;
bs.nosleep = 1;
break;
default:
printf("unrecognized feature flags: %02x\n", payload);
break;
}
break;
default:
printf("unrecognized command: %02x\n", cmd);
break;
}
}
// Padding
irw_writeb(o, 0);
return errors;
}