On Wed, Apr 29, 2020 at 06:23:07PM +0200, marek.bykowski@gmail.com wrote:
From: Marek Bykowski marek.bykowski@gmail.com
Malloc gets initialized with a call to mem_malloc_init() with the address the allocation starts to and its size. Currently it is not possible to move the malloc from one memory area to another as the malloc would eventually fail.
This patch adds in the ability to re-init the malloc with the updated start address and the size.
One of the use cases of this feature is SPL U-Boot running from within the static memory and calling to malloc init from within board_init_f():
arch/arm/cpu/armv8/start.S:reset vector arch/arm/cpu/armv8/start.S:main() arch/arm/lib/crt0_64.S:board_init_f() board/<my_board>/common/spl.c:board_init_f() board/<my_board>/common/spl.c:mem_malloc_init((ulong)CONFIG_SYS_SPL_MALLOC_START, CONFIG_SYS_SPL_MALLOC_SIZE);
Shortly after the DDR (main) memory is init and ready we call to malloc init again but this time with the start address in the DDR memory and a much greater size for moving the allocation off the static to the DDR memory:
board/<my_board>/common/spl.c:mem_malloc_init((ulong)CONFIG_SPL_MALLOC_OFFSET, CONFIG_SPL_MALLOC_SIZE);
Where CONFIG_SYS_SPL_MALLOC_START and CONFIG_SPL_MALLOC_OFFSET are the start addresses of the malloc in the static and DDR memories respectively and CONFIG_SYS_SPL_MALLOC_SIZE=SZ_16K and CONFIG_SPL_MALLOC_SIZE=SZ_2M are the sizes of the mallocs in these memories. Note, now we have a much greater memory, enlarging from 16K to 2M, available for allocation.
There is an alternative approach already existing in U-Boot with the use of an early (simplified) malloc and the proper (dlamalloc) malloc however necessitating managing the two mallocs whereas this approach proposes using a single dlmalloc.
Signed-off-by: Marek Bykowski marek.bykowski@gmail.com
Applied to u-boot/master, thanks!