On Thu, 16 Apr 2020 at 23:40, <nikita.shubin@xxxxxxxxxxx> wrote:
>
> Hi Mathieue,
>
> Hi Nikita,
>
> On Mon, Apr 06, 2020 at 02:33:08PM +0300, nikita.shubin@xxxxxxxxxxx wrote:
>
> In case elf file interrupt vector is not supposed to be at OCRAM_S,
> it is needed to write elf entry point to OCRAM_S + 0x4, to boot M4
> firmware.
>
> Otherwise firmware located anywhere besides OCRAM_S won't boot.
>
> The firmware must set stack poiner as first instruction:
>
> Reset_Handler:
> ldr sp, = __stack /* set stack pointer */
>
> Signed-off-by: Nikita Shubin <NShubin@xxxxxxxxxx>
>
>
> The address in the SoB has to match what is found in the "From:" field of the
> email header. Checkpatch is complaining about that, something I would have
> expected to be fixed before sending this set out.
>
> Noted and will be fixed.
>
> ---
> drivers/remoteproc/imx_rproc.c | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
> index 3e72b6f38d4b..bebc58d0f711 100644
> --- a/drivers/remoteproc/imx_rproc.c
> +++ b/drivers/remoteproc/imx_rproc.c
> @@ -45,6 +45,8 @@
>
> #define IMX7D_RPROC_MEM_MAX 8
>
> +#define IMX_BOOT_PC 0x4
> +
> /**
> * struct imx_rproc_mem - slim internal memory structure
> * @cpu_addr: MPU virtual address of the memory region
> @@ -85,6 +87,7 @@ struct imx_rproc {
> const struct imx_rproc_dcfg *dcfg;
> struct imx_rproc_mem mem[IMX7D_RPROC_MEM_MAX];
> struct clk *clk;
> + void __iomem *bootreg;
> };
>
> static const struct imx_rproc_att imx_rproc_att_imx7d[] = {
> @@ -162,11 +165,16 @@ static int imx_rproc_start(struct rproc *rproc)
> struct device *dev = priv->dev;
> int ret;
>
> + /* write entry point to program counter */
> + writel(rproc->bootaddr, priv->bootreg);
>
>
> What happens on all the other IMX systems where this fix is not needed? Will
> they continue to work properly?
>
> Yes, my bad, it is also needed for IMX6 (but even so i need to study this topic more carefully),
> this should be applied exclusively for imx7d for now, and if will be needed someone
> with imx6 hardware to test on can extend this on imx6 also.
>
>
>
>
> +
> ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
> dcfg->src_mask, dcfg->src_start);
> if (ret)
> dev_err(dev, "Failed to enable M4!\n");
>
> + dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr);
> +
> return ret;
> }
>
> @@ -182,6 +190,9 @@ static int imx_rproc_stop(struct rproc *rproc)
> if (ret)
> dev_err(dev, "Failed to stop M4!\n");
>
> + /* clear entry points */
> + writel(0, priv->bootreg);
> +
> return ret;
> }
>
> @@ -243,7 +254,8 @@ static void *imx_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
> static const struct rproc_ops imx_rproc_ops = {
> .start = imx_rproc_start,
> .stop = imx_rproc_stop,
> - .da_to_va = imx_rproc_da_to_va,
> + .da_to_va = imx_rproc_da_to_va,
> + .get_boot_addr = rproc_elf_get_boot_addr,
>
>
> How is this useful? Sure it will set rproc->bootaddr in rproc_fw_boot() but
> what good does that do when it is invariably set again in imx_rproc_start() ?
>
> The priv->bootreg is the address where we are writing Entry Point and it is fixed,
> 0x04 address is translated to 0x00180004, so don't quite understand you we
> are writing rproc->bootaddr into priv->bootreg, not wiseversa.
>
What is your reason to set ops->get_boot_addr ? How does that help
the work done in this patch?
>
> };
>
> static int imx_rproc_addr_init(struct imx_rproc *priv,
> @@ -360,6 +372,8 @@ static int imx_rproc_probe(struct platform_device *pdev)
> goto err_put_rproc;
> }
>
> + priv->bootreg = imx_rproc_da_to_va(rproc, IMX_BOOT_PC, sizeof(u32));
> +
> /*
> * clk for M4 block including memory. Should be
> * enabled before .start for FW transfer.
> --
> 2.25.1
>
