basecmd: Avoid calling malloc() from main code

Introduce a new board function alloc_chunk() to allocate dynamic
memory.  This allows the board code to implement memory allocations
without using the standard malloc() interface.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2017-05-06 22:29:08 -04:00
parent 8f1d0c2a7c
commit f331936969
6 changed files with 66 additions and 45 deletions

View file

@ -1,15 +1,18 @@
// AVR miscellaneous platform code
//
// 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_AVR_STACK_SIZE
#include "board/misc.h" // alloc_maxsize
#include "command.h" // shutdown
#include "compiler.h" // ALIGN
#include "sched.h" // sched_shutdown
// Optimized crc16_ccitt for the avr processor
uint16_t
@ -21,17 +24,31 @@ crc16_ccitt(char *buf, uint8_t len)
return crc;
}
// Return the maximum allocation size that can succeed up to 'reqsize'
size_t
alloc_maxsize(size_t reqsize)
// 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;
int16_t maxsize = __malloc_heap_end - __brkval - 2;
if (maxsize < 0)
return 0;
if (reqsize < maxsize)
return reqsize;
return maxsize;
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);
}