visionfive2-sz.cpp

// SPDX-License-Identifier: MIT
// lrzsz doesn't work for VisionFive2's UART boot for some reason.
// Here's the hacky replacement.
// Usage: picocom -b 115200 -s "./visionfive2-sz" /dev/ttyUSB0
//        Ctrl-A Ctrl-S then "recovery.bin"

#include <cinttypes>
#include <cstdio>
#include <unistd.h>
#include <fcntl.h>
#include <boost/crc.hpp>

#define BLOCK_SIZE 128
// 20MB
#define MAX_FILE_SIZE 20 * 1024 * 1024

int main(int argc, char *argv[]) {
    if (argc <= 1) {
        fprintf(stderr, "missing file\n");
        return 1;
    }

    int fd = open(argv[1], O_RDONLY);
    if (fd < 0) {
        perror("open() failed");
        return 1;
    }
    uint8_t *data = new uint8_t[MAX_FILE_SIZE];
    uint32_t size = 0;

    int read_size;
    do {
        read_size = read(fd, data + size, MAX_FILE_SIZE - size);
        if (read_size < 0) {
            perror("read() failed");
            return 1;
        }
        size += read_size;
    } while (read_size > 0);
    if (size >= MAX_FILE_SIZE) {
        fprintf(stderr, "file too large\n");
        return 1;
    }

    fprintf(stderr, "\n");

    char c = getchar();
    while (c != 'C') c = getchar();

    uint32_t sent = 0;
    while (sent < size) {
        boost::crc_optimal<16, 0x1021, 0, 0, false, false>  crc;

        uint8_t blockid = (sent / BLOCK_SIZE) + 1;  // wrap 0xff to 0x00
        uint8_t blockid_r = 255 - blockid;

        uint32_t to_send = size - sent;
        if (to_send > BLOCK_SIZE) to_send = BLOCK_SIZE;
        uint32_t padding = BLOCK_SIZE - to_send;

        putchar(0x01);  // SOH
        putchar(blockid);
        putchar(blockid_r);

        crc.process_bytes(data+sent, to_send);
        for (int i = 0; i < to_send; i++) {
            putchar(data[sent + i]);
        }
        for (int i = 0; i < padding; i++) {
            crc.process_byte(0x1a);
            putchar(0x1a);  // CPMEOF
        }

        uint16_t crc_val = crc.checksum();
        putchar(crc_val >> 8); // CRC hi
        putchar(crc_val & 0xff); // CRC lo
        fflush(stdout);

        c = getchar();
        while (c == 'C') c = getchar();
        if (c == 0x06) {
            // ACK
            sent += to_send;
            fprintf(stderr, "\033[G\033[KSent %d/%d", sent, size);
            fflush(stderr);
        } else {
            // Other error
            fprintf(stderr, "\nSend error %d\n", c);
        }
    }
    fprintf(stderr, "\n");

    putchar(0x04); // EOT
    fflush(stdout);
    
    c = getchar();
    while (c == 'C') c = getchar();
    if (c == 0x06) {
        // ACK
        fprintf(stderr, "Transmit success\n");
    } else {
        // Other error
        fprintf(stderr, "Transmit error %d\n", c);
    }

    return 0;
}