logging.c

   1 #include <avr/io.h>
   2 #include <avr/eeprom.h>
   3
   4 #include "logging.h"
   5
   6 #define LOG_BUFFER 32
   7 static unsigned char log_buffer_ee[LOG_BUFFER] EEMEM;
   8 static unsigned char log_buffer_count;
   9 static unsigned char log_buffer[LOG_BUFFER];
  10 static unsigned char log_state EEMEM;
  11 /* Upper 4 bits are reset count, lower 4 bits are reset reason from MCUSR */
  12 static unsigned char reboot_count EEMEM = 0;
  13 static unsigned char can_write_eeprom = 0;
  14 static uint16_t flushed_end;
  15
  16 void log_set_state(unsigned char val)
  17 {
  18         if (can_write_eeprom)
  19                 eeprom_write_byte(&log_state, val);
  20 }
  21
  22 void init_log()
  23 {
  24         unsigned char r_count;
  25
  26         r_count = eeprom_read_byte(&reboot_count);
  27         r_count >>= 4;
  28
  29         if (r_count < 5) {
  30                 r_count++;
  31                 eeprom_write_byte(&reboot_count,
  32                         (r_count << 4) | (MCUSR & 0xF));
  33                 MCUSR = 0;
  34                 can_write_eeprom = 1;
  35         } else {
  36                 //eeprom_write_byte(&log_state, 0xFF);
  37                 can_write_eeprom = 0;
  38         }
  39
  40         log_set_state(1);
  41         log_buffer_count = 0;
  42         flushed_end = 0;
  43 }
  44
  45 void log_byte(unsigned char byte) {
  46         if (log_buffer_count >= LOG_BUFFER)
  47                 return;
  48
  49         // eeprom_write_word(&log_buffer[log_buffer_count], word);
  50         log_buffer[log_buffer_count++] = byte;
  51
  52         if (log_buffer_count == LOG_BUFFER)
  53                 log_flush();
  54 }
  55
  56 void log_word(uint16_t word) {
  57         log_byte(word & 0xFF);
  58         log_byte(word >> 8);
  59 }
  60
  61 void log_flush() {
  62         unsigned char i;
  63
  64         if (!can_write_eeprom)
  65                 return;
  66
  67         for (i=flushed_end; i < log_buffer_count; i++) {
  68                 eeprom_write_byte(&log_buffer_ee[i],
  69                         log_buffer[i]);
  70         }
  71
  72         flushed_end = i;
  73
  74         if (flushed_end == LOG_BUFFER)
  75                 log_set_state(0x42);
  76 }
  77