On Wed, Feb 12, 2020 at 1:21 PM Stefan Roese <s...@denx.de> wrote:
>
> It has been noticed on MT7628/88 platforms, that booting the RAM image
> does not work reliably. Sometimes it works and sometimes not. Debugging
> showed that this "might" be a cache related issue as very strange
> errors occured (output corrupted etc).
>
> This patch adds a cache flush for the complete SDRAM area to the go cmd
> before jumping to the entry point. The complete area is flushed as we
> don't know at this point, how big the area of the "application" really
> is.
>
> Signed-off-by: Stefan Roese <s...@denx.de>
> Cc: Daniel Schwierzeck <daniel.schwierz...@gmail.com>
> Cc: Mauro Condarelli <mc5...@mclink.it>
> Cc: Weijie Gao <weijie....@mediatek.com>
> ---
> cmd/boot.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/cmd/boot.c b/cmd/boot.c
> index 9150fce80b..968522face 100644
> --- a/cmd/boot.c
> +++ b/cmd/boot.c
> @@ -9,10 +9,13 @@
> */
> #include <common.h>
> #include <command.h>
> +#include <cpu_func.h>
> #include <net.h>
>
> #ifdef CONFIG_CMD_GO
>
> +DECLARE_GLOBAL_DATA_PTR;
> +
> /* Allow ports to override the default behavior */
> __attribute__((weak))
> unsigned long do_go_exec(ulong (*entry)(int, char * const []), int argc,
> @@ -33,6 +36,13 @@ static int do_go(cmd_tbl_t *cmdtp, int flag, int argc,
> char * const argv[])
>
> printf ("## Starting application at 0x%08lX ...\n", addr);
>
> + /*
> + * Flush cache before jumping to application. Let's flush the
> + * whole SDRAM area, since we don't know the size of the image
> + * that was loaded.
> + */
> + flush_cache(gd->bd->bi_memstart, gd->bd->bi_memsize);
> +
> /*
> * pass address parameter as argv[0] (aka command name),
> * and all remaining args
> --
> 2.25.0
>
I think that's not right for all architectures or cache-coherent
systems. It would be better
to implement do_go_exec() in arch/mips/libs/bootm.c because this function is
already annotated as weak.
--
- Daniel
