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-rw-r--r--zbootloader.c361
1 files changed, 0 insertions, 361 deletions
diff --git a/zbootloader.c b/zbootloader.c
deleted file mode 100644
index df168df..0000000
--- a/zbootloader.c
+++ /dev/null
@@ -1,361 +0,0 @@
-#include <zbootloader.h>
-#include <zeta.h>
-#include <stddef.h>
-#include <string.h>
-
-/* volatile uint8_t rx_head = 0; */
-/* volatile uint8_t rx_tail = 0; */
-/* volatile uint8_t rx_fifo[FIFO_LEN]; */
-
-struct fifo {
- uint8_t head;
- uint8_t tail;
- uint8_t data[FIFO_LEN];
-};
-
-volatile struct fifo rx_fifo = {0, 0, {0}};
-
-uint8_t
-fifo_pop(struct fifo *fifo)
-{
- uint8_t ret = fifo->data[fifo->head];
- if (++fifo->head >= LEN(fifo->data))
- fifo->head = 0;
- return ret;
-}
-
-void
-fifo_push(struct fifo *fifo, uint8_t v)
-{
- fifo->data[fifo->tail] = v;
-
- if (++fifo->tail >= LEN(fifo->data))
- fifo->tail = 0;
-}
-
-bool
-fifo_empty(const struct fifo *fifo)
-{
- return (fifo->head == fifo->tail);
-}
-
-void
-fifo_clear(struct fifo *fifo)
-{
- fifo->head = 0;
- fifo->tail = 0;
-}
-
-static const uint8_t sio_a_cfg[] = {
- 0b00011000, // Reset channel
- 4 , // wr4
- 0b00000100, // X1 clock, one stop bit, no parity
- 1 , // wr1
- SIO_RX_INT_MD0 | SIO_RX_INT_MD1, // interrupt on every Rx, no wait function
- 3 , // wr3
- 0b11000001, // enable Rx - 8 bit char
- 5 , // wr5
- 0b01101000 // enable Tx - 8 bit char
-};
-
-extern void *rx_isr_ptr;
-extern void *ctc0_isr_ptr;
-extern void *ctc1_isr_ptr;
-extern void *ctc2_isr_ptr;
-extern void *ctc3_isr_ptr;
-
-#define ISR_OFFSET(x) ((unsigned int)&x)
-
-static const unsigned char sio_b_cfg[] = {
- 0b00011000, // Reset channel
- 2 , // load interrupt vector
- ISR_OFFSET(rx_isr_ptr) // int_table_rx
-};
-
-/* int_table: */
-/* int_table_rx: */
-/* dw rx_isr */
-
-void
-rx_isr(void) __critical __interrupt(0)
-{
- fifo_push(&rx_fifo, sio_a_data);
-}
-
-static volatile uint32_t millis = 0;
-
-void
-ctc3_isr(void) __critical __interrupt(1)
-{
- millis += 5;
-}
-
-uint32_t
-clock(void)
-{
- volatile uint32_t ret;
- DI;
- ret = millis;
- EI;
- return ret;
-}
-
-void
-putbyte(unsigned char b)
-{
- unsigned char ctrl = 0;
-
- sio_a_data = b;
-
- while (!(ctrl & 0x04)) {
- sio_a_ctrl = 0;
- ctrl = sio_a_ctrl;
- }
-}
-
-static volatile int32_t errno = 0;
-
-uint8_t
-getbyte(void)
-{
- uint8_t b;
- uint32_t ms = clock();
- errno = 0;
- while (fifo_empty(&rx_fifo)) {
- if (clock() - ms > TIMEOUT_MS) {
- errno = ERR_TIMEOUT;
- return 0;
- }
- }
- DI;
- b = fifo_pop(&rx_fifo);
- EI;
- return b;
-}
-
-void
-flush(void)
-{
- DI;
- fifo_clear(&rx_fifo);
- EI;
-}
-
-
-// Hamming(7,4) encoding
-uint8_t
-encode(uint8_t x)
-{
- uint8_t y = 0;
- const uint8_t c[4] = {0x61, 0x52, 0x34, 0x78};
-
- for (uint8_t i = 0; i < 4; ++i)
- y ^= ((x >> i) & 1) ? c[i] : 0;
-
- return y;
-}
-
-// Hamming(7,4) decoding
-uint8_t
-decode(uint8_t x)
-{
- uint8_t p = 0;
- const uint8_t r[7] = {6, 5, 3, 7, 1, 2, 4};
-
- for (int i = 0; i < 7; ++i)
- p ^= ((x >> i) & 1) ? r[i] : 0;
-
- // Assume simple error, attempt correction
- if (p) {
- size_t i = 0;
-
- for (i = 0; i < LEN(r); ++i) {
- if (r[i] == x)
- break;
- }
-
- x ^= (1 << i);
- }
-
- return x & 0x0F;
-}
-
-
-int
-read(void *buf, size_t count)
-{
- uint8_t b;
- uint8_t *p = buf;
-
- for (int n = 0; n < count; ++n) {
- b = decode(getbyte());
- if (errno)
- return errno;
-
- b |= (decode(getbyte()) << 4);
- if (errno)
- return errno;
-
- p[n] = b;
- }
-
- return 0;
-}
-
-int
-write(const void *buf, size_t count)
-{
- const uint8_t *p = buf;
-
- for (size_t i = 0; i < count; ++i) {
- putbyte(encode(p[i] & 0x0F));
- putbyte(encode((p[i] >> 4) & 0x0F));
- }
-
- return 0;
-}
-
-int
-read_header(struct header *header)
-{
- int err;
- uint8_t ack;
- uint16_t checksum;
-
- while (1) {
- if ((err = read(header, sizeof(*header))))
- return err;
-
- checksum = header->checksum;
- header->checksum = 0;
-
- if (checksum == crc16(header, sizeof(*header))) {
- header->checksum = checksum;
- ack = ACK;
- write(&ack, sizeof(ack));
- return 0;
- } else {
- ack = NACK;
- write(&ack, sizeof(ack));
- }
- }
-}
-
-int
-read_buf(size_t len, void *buf)
-{
- int err;
- uint8_t ack;
- uint16_t checksum;
-
- for (int i = 0; i < MAX_TRANS_ATTEMPTS; ++i) {
- // TODO: reduce code?
- if ((err = read(&checksum, sizeof(checksum)))
- || (err = read(buf, len)))
- break;
-
- if (checksum == crc16(buf, len)) {
- ack = ACK;
- write(&ack, sizeof(ack));
- return 0;
- } else {
- ack = NACK;
- write(&ack, sizeof(ack));
- }
- }
-
- return -1;
-}
-
-int
-write_buf(size_t len, const void *buf)
-{
- int err;
- uint8_t ack = NACK;
- uint16_t checksum = crc16(buf, len);
-
- for (int i = 0; i < MAX_TRANS_ATTEMPTS; ++i){
- write(&checksum, sizeof(checksum));
- write(buf, len);
-
- // If TIMEOUT sending just give up
- if ((err = read(&ack, sizeof(ack))))
- return err;
-
- if (ack == ACK)
- return 0;
- }
-
- return -1;
-}
-
-// TODO: Restart after timeouts
-void
-loop(void)
-{
- struct header header;
- uint8_t buf[MAX_PACKET_SIZE];
-
- while (1) {
- if (read_header(&header)) {
- flush();
- continue;
- }
-
- switch (header.type) {
- case CMD_BOOT:
- ((void (*)(void))header.address)();
- break;
-
- case CMD_READ:
- write_buf(header.length, (const void *)header.address);
- break;
-
- case CMD_WRITE:
- if (!read_buf(header.length, buf))
- memcpy((void *)header.address, buf, header.length);
- break;
-
- case CMD_ECHO:
- if (!read_buf(header.length, buf))
- write_buf(header.length, buf);
- break;
-
- default:
- break;
- }
-
- flush();
- }
-}
-
-int
-main(void)
-{
- // Init CTC
- // 16 prescaler, timer mode
- ctc_channel_1 = (CTC_CLK_TRG_BIT | CTC_TIME_CONST_BIT | CTC_RST_BIT
- | CTC_CTRL_OR_VECTOR_BIT);
- ctc_channel_1 = (CPU_FREQ / 16 / 9600);
-
- // 200Hz clock
- ctc_channel_3 = (CTC_INT_BIT | CTC_PRESCALER_BIT | CTC_CLK_TRG_BIT |
- CTC_TIME_CONST_BIT | CTC_RST_BIT | CTC_CTRL_OR_VECTOR_BIT);
- ctc_channel_3 = (CPU_FREQ / 256 / 36);
- ctc_channel_0 = ISR_OFFSET(ctc3_isr_ptr) | (3 << 1);
-
- // Init SIO
- for (uint8_t i = 0; i < LEN(sio_a_cfg); ++i)
- sio_a_ctrl = sio_a_cfg[i];
-
- for (uint8_t i = 0; i < LEN(sio_b_cfg); ++i)
- sio_b_ctrl = sio_b_cfg[i];
-
- // Interrupt mode 2
- IM(2);
- // Enable interrupts
- EI;
-
- loop();
- return 0;
-}
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