boot/common/src/uboot/compress/mm.h

/*
 * linux/compr_mm.h
 *
 * Memory management for pre-boot and ramdisk uncompressors
 *
 * Authors: Alain Knaff <alain@knaff.lu>
 *
 */

#ifndef DECOMPR_MM_H
#define DECOMPR_MM_H

/* Code active when included from pre-boot environment: */

/*
 * Some architectures want to ensure there is no local data in their
 * pre-boot environment, so that data can arbitrarily relocated (via
 * GOT references).  This is achieved by defining STATIC_RW_DATA to
 * be null.
 */
#ifndef STATIC_RW_DATA
#define STATIC_RW_DATA static
#endif

/* A trivial malloc implementation, adapted from
 *  malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
 */
STATIC_RW_DATA unsigned long malloc_ptr;
STATIC_RW_DATA int malloc_count;
extern unsigned long free_mem_ptr;
extern unsigned long free_mem_end_ptr;

static void *malloc(int size)
{
	void *p;

	if (size < 0)
		return NULL;
	if (!malloc_ptr)
		malloc_ptr = free_mem_ptr;

	malloc_ptr = (malloc_ptr + 3) & ~3;     /* Align */

	p = (void *)malloc_ptr;
	malloc_ptr += size;

	if (free_mem_end_ptr && malloc_ptr >= free_mem_end_ptr)
		return NULL;

	malloc_count++;
	return p;
}

static void free(void *where)
{
	malloc_count--;
	if (!malloc_count)
		malloc_ptr = free_mem_ptr;
}

#define large_malloc(a) malloc(a)
#define large_free(a) free(a)

#define INIT

#endif /* DECOMPR_MM_H */