From 4ca2218403bc297ffc4d9371bd26afccbb7cd5db Mon Sep 17 00:00:00 2001 From: Sean Cross Date: Mon, 25 Feb 2019 13:49:38 +0800 Subject: [PATCH] ice40: experimental rom patching support We can now do away with the `iceunpack`/`icebram`/`icepack` dance and simply patch files on the fly. This should simplify development, since you only need two files (the bitstream and the replacement rom), rather than four files (the bitstream, the replacement rom, the random contents, and the output file). Signed-off-by: Sean Cross --- ice40.c | 438 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ice40.h | 28 ++++ 2 files changed, 466 insertions(+) create mode 100644 ice40.c create mode 100644 ice40.h diff --git a/ice40.c b/ice40.c new file mode 100644 index 0000000..db3a831 --- /dev/null +++ b/ice40.c @@ -0,0 +1,438 @@ +#include +#include +#include "ice40.h" + +#define MAX(x, y) (x) > (y) ? (x) : (y) +#define DEBUG_PRINT(...) + +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 ora_matches = 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); + for (i = 0; i < ((bs.current_width * bs.current_height) / 8); i += 2) + { + uint16_t word = + ((irw_readb(f) << 8) & 0x0000ff00) + | + ((irw_readb(f) << 0) & 0x000000ff) + ; + int i; + + if (word) { + int found = 0; + int start = ora_ptr - 64; + int end = ora_ptr + 64; + if (start < 0) + start = 0; + if (end > 8192) + end = 8192; + for (i = start; i < end; i++) { + if (ora16[i] == word) { + found = 1; + word = oro16[i]; + ora_matches++; + ora_ptr = i; + break; + } + } + if (!found) { + printf("couldn't find word %04x (ora_ptr: %d matches: %d)\n", word, ora_ptr, ora_matches); + errors++; + } + } + else { + ora_ptr++; + // DEBUG_PRINT("word is 0, ptr is %d\n", ora_ptr); + } + irw_writeb(o, word >> 8); + irw_writeb(o, 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; + ora_matches = 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; +} \ No newline at end of file diff --git a/ice40.h b/ice40.h new file mode 100644 index 0000000..10bdabf --- /dev/null +++ b/ice40.h @@ -0,0 +1,28 @@ +#ifndef _ICE40_H +#define _ICE40_H + +#include +#include + +typedef struct irw_file +{ + FILE *f; + uint16_t crc; + uint32_t offset; + void *hook_data; + int (*read_hook)(void *data); + int (*write_hook)(void *data, uint8_t b); +} IRW_FILE; + +struct irw_file *irw_open(const char *filename, const char *mode); +struct irw_file *irw_open_fake(void *hook_data, + int (*read_hook)(void *data), + int (*write_hook)(void *data, uint8_t b)); +int irw_readb(struct irw_file *f); +int irw_writeb(struct irw_file *f, int c); +void irw_close(struct irw_file **f); + +int ice40_patch(struct irw_file *f, struct irw_file *rom, + struct irw_file *o, uint32_t byte_count); + +#endif /* _ICE40_H */ \ No newline at end of file