diff options
Diffstat (limited to 'src/avr/main.c')
| -rw-r--r-- | src/avr/main.c | 55 |
1 files changed, 54 insertions, 1 deletions
diff --git a/src/avr/main.c b/src/avr/main.c index 4a3f871a..a210300f 100644 --- a/src/avr/main.c +++ b/src/avr/main.c @@ -1,9 +1,13 @@ // Main starting point for AVR boards. // -// Copyright (C) 2016 Kevin O'Connor <kevin@koconnor.net> +// Copyright (C) 2016,2017 Kevin O'Connor <kevin@koconnor.net> // // This file may be distributed under the terms of the GNU GPLv3 license. +#include <avr/io.h> // AVR_STACK_POINTER_REG +#include <stdlib.h> // __malloc_heap_end +#include <string.h> // memset +#include <util/crc16.h> // _crc_ccitt_update #include "autoconf.h" // CONFIG_MCU #include "command.h" // DECL_CONSTANT #include "irq.h" // irq_enable @@ -11,6 +15,55 @@ DECL_CONSTANT(MCU, CONFIG_MCU); + +/**************************************************************** + * Memmory allocation + ****************************************************************/ + +// Allocate an area of memory +void * +alloc_chunk(size_t size) +{ + void *data = malloc(size); + if (!data) + shutdown("alloc_chunk failed"); + memset(data, 0, size); + return data; +} + +// Allocate an array of chunks +void * +alloc_chunks(size_t size, size_t count, size_t *avail) +{ + uint16_t memend = ALIGN(AVR_STACK_POINTER_REG, 256); + __malloc_heap_end = (void*)memend - CONFIG_AVR_STACK_SIZE; + extern char *__brkval; + uint16_t maxsize = __malloc_heap_end - __brkval - 2; + if ((int16_t)maxsize < 0) + maxsize = 0; + if (count * size > maxsize) + count = maxsize / size; + if (!count) + shutdown("alloc_chunks failed"); + *avail = count; + return alloc_chunk(count * size); +} + + +/**************************************************************** + * Misc functions + ****************************************************************/ + +// Optimized crc16_ccitt for the avr processor +uint16_t +crc16_ccitt(char *buf, uint8_t len) +{ + uint16_t crc = 0xFFFF; + while (len--) + crc = _crc_ccitt_update(crc, *buf++); + return crc; +} + // Main entry point for avr code. int main(void) |