CCPIL, a CC1110 hardware loader for Raspberry Pi - to solve the initial bootloader problem.

ccpil/hex.c

@@ -0,0 +1,198 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <arpa/inet.h>
+
+static uint8_t tolowercase(uint8_t ch)
+{
+    if ((ch >= 'A') && (ch <= 'Z'))
+        return ch + 0x20;       // Convert uppercase to lowercase
+    return ch;
+}
+
+static int8_t parseHexDigit(uint8_t digit)
+{
+    digit = tolowercase(digit);
+    if (isdigit(digit))
+        return (int8_t)digit - '0';
+    if ((digit >= 'a') && (digit <= 'f'))
+        return (int8_t)digit + 0xA - 'a';
+    return -1;      // Error case - input wasn't a valid hex digit
+}
+
+
+static int hexstring_parse(const char *hexstr, uint8_t *buf, size_t *buflen)
+{
+    size_t hexstrlen = *buflen * 2;
+    size_t i;
+
+    if (hexstrlen & 0x1)
+    {
+        fprintf(stderr, "hexstring_parse: not even\n");
+        return 1;
+    }
+
+    if (*buflen < hexstrlen/2)
+    {
+        fprintf(stderr, "hexstring_parse: buffer too small %zu < %zu\n", *buflen, hexstrlen/2);
+        return 1;
+    }
+
+    for (i=0;i<hexstrlen;i+=2)
+    {
+        int8_t a, b;
+        if (-1 == (a = parseHexDigit(hexstr[i])))
+        {
+            fprintf(stderr, "hexstring_parse: bad digit 0x%02X\n", hexstr[i]);
+            return 1;
+        }
+        if (-1 == (b = parseHexDigit(hexstr[i+1])))
+        {
+            fprintf(stderr, "hexstring_parse: bad digit 0x%02X\n", hexstr[i+1]);
+            return 1;
+        }
+        *buf++ = (a << 4) | b;
+    }
+
+    *buflen = hexstrlen/2;
+
+    return 0;
+}
+
+static int read_record(uint8_t *buf, size_t buflen, const char *line, bool *eof)
+{
+    size_t len;
+    uint8_t sum = 0;
+    uint8_t record_sum;
+    uint8_t record_len;
+    uint8_t type;
+    uint16_t addr;
+    uint8_t data[256];
+    int i;
+
+    *eof = false;
+
+    if (line[0] != ':')
+    {
+        fprintf(stderr, "bad hexfile: no start\n");
+        return 1;
+    }
+    line+=1;
+
+    len = 1;
+    if (0 != hexstring_parse(line, &record_len, &len))
+    {
+        fprintf(stderr, "bad hexfile: no len '%s'\n", line);
+        return 1;
+    }
+    line+=len * 2;
+
+    len = 2;
+    if (0 != hexstring_parse(line, (uint8_t *)&addr, &len))
+    {
+        fprintf(stderr, "bad hexfile: no addr\n");
+        return 1;
+    }
+    addr = ntohs(addr);
+    line+=len * 2;
+
+    len = 1;
+    if (0 != hexstring_parse(line, &type, &len))
+    {
+        fprintf(stderr, "bad hexfile: no type\n");
+        return 1;
+    }
+    line+=len * 2;
+
+    len = record_len;
+    if (0 != hexstring_parse(line, data, &len))
+    {
+        fprintf(stderr, "bad hexfile: no data\n");
+        return 1;
+    }
+    line+=len * 2;
+
+    len = 1;
+    if (0 != hexstring_parse(line, &record_sum, &len))
+    {
+        fprintf(stderr, "bad hexfile: no sum\n");
+        return 1;
+    }
+    line+=len * 2;
+
+    if (type == 0)
+    {
+        sum += record_len;
+        sum += addr >> 8;
+        sum += addr & 0xFF;
+
+        for (i=0;i<record_len;i++)
+            sum += data[i];
+        sum = (sum ^ 0xFF) + 1;
+
+        if (sum != record_sum)
+        {
+            fprintf(stderr, "bad hexfile, checksum mismatch\n");
+            return 1;
+        }
+
+        if (addr + record_len > buflen)
+        {
+            fprintf(stderr, "bad hexfile, too big\n");
+            return 1;
+        }
+        memcpy(buf + addr, data, record_len);
+    }
+    else
+    if (type == 1)
+    {
+        *eof = true;
+    }
+    else
+    {
+        fprintf(stderr, "bad hexfile: unknown record type %02X\n", type);
+    }
+
+    return 0;
+}
+
+int read_hexfile(uint8_t *buf, size_t buflen, const char *filename)
+{
+    FILE *fp;
+    char line[1024];
+    bool eof;
+
+    if (NULL == (fp = fopen(filename, "ro")))
+        return 1;
+
+    while (NULL != fgets(line, sizeof(line), fp))
+    {
+        char *p = (line + strlen(line)) - 1;
+
+        while(p > line)
+        {
+            if (isspace((int)(*p)))
+                *p = 0;
+            p--;
+        }
+
+        if (0 != read_record(buf, buflen, line, &eof))
+            goto fail;
+
+        if (eof)
+            break;
+    }
+
+    fclose(fp);
+    return 0;
+fail:
+    fclose(fp);
+    return 1;
+}
+
+