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Hex Dump (hexdump)

Outputs memory data in the classic hex dump format, 16 bytes per line, including address, hexadecimal values, and ASCII characters.

Output Format​

00000000: 48 65 6c 6c 6f 20 57 6f 72 6c 64 21 00 00 00 00 |Hello World!....|
00000010: 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 |................|

Each line consists of three parts:

  • Address — 8-digit hex address, incremented based on the base parameter
  • Hex — 2 hex digits per byte + space, padded with alignment when fewer than 16 bytes
  • ASCII — Printable characters (0x20~0x7e) shown as-is, others displayed as .

API​

void hexdump(void (*output)(char), unsigned long base, void * buf, int len);
  • output — Character output callback function, called once per character, cannot be NULL
  • base — Starting address value (for display only, does not affect data reading)
  • buf — Data buffer to dump
  • len — Data length (bytes)

Usage Examples​

Output to shell​

static void shell_output(char c)
{
    shell_printf("%c", c);
}

hexdump(shell_output, 0x80000000, data, sizeof(data));

Output to dynamic string​

static struct ds_t * g_ds;

static void ds_output(char c)
{
    ds_append_char(g_ds, c);
}

g_ds = ds_alloc();
hexdump(ds_output, 0, buf, len);
/* g_ds contains the complete hex dump text */
ds_free(g_ds);

Debug register dump​

hexdump(shell_output, 0x40000000, mmio_base, 64);
/* Displays 64 bytes of register content starting at 0x40000000 */