On 24-04-30, Marco Felsch wrote:
> This ports U-Boot commit:
>
> | commit 2f3c92060dcd6bc9cfd3e2e344a3e1745ca39f09
> | Author: Peng Fan <peng.fan@xxxxxxx>
> | Date: Thu Jul 9 13:39:26 2020 +0800
> |
> | imx8m: workaround ROM serror
> |
> | ROM SError happens on two cases:
> |
> | 1. ERR050342, on iMX8MQ HDCP enabled parts ROM writes to GPV1 register, but
> | when ROM patch lock is fused, this write will cause SError.
> |
> | 2. ERR050350, on iMX8MQ/MM/MN, when the field return fuse is burned, HAB
> | is field return mode, but the last 4K of ROM is still protected and cause
> | SError.
> |
> | Since ROM mask SError until ATF unmask it, so then ATF always meets the
> | exception. This patch works around the issue in SPL by enabling SPL
> | Exception vectors table and the SError exception, take the exception
> | to eret immediately to clear the SError.
> |
> | Signed-off-by: Ye Li <ye.li@xxxxxxx>
> | Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
>
> Other than U-Boot we don't support exceptions in PBL and therefore we
> can handle it simpler by installing an dummy exception table which does
> nothing. The table gets overriden by TF-A later on anyway.
>
> Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
> ---
> Hi all,
>
> I'm not sure if the relocation should be done within the erratum
> handler or if we should move it into the lowlevel code per default for
> all i.MX8M platforms since the board files call it anyway after the
> lowlevel init. In the later case this would be an separate patch to drop
> the pattern:
>
> lowlevel_setup();
> relocate_to_current_adr();
>
> from the board files.
...
> diff --git a/arch/arm/mach-imx/errata.c b/arch/arm/mach-imx/errata.c
> new file mode 100644
> index 000000000000..ef8de91a9278
> --- /dev/null
> +++ b/arch/arm/mach-imx/errata.c
> @@ -0,0 +1,22 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +#include <asm/barebox-arm.h>
> +#include <asm/system.h>
> +#include <mach/imx/errata.h>
> +
> +#ifdef CONFIG_CPU_V8
> +
> +extern unsigned long early_imx8m_vectors;
> +
> +void erratum_050350_imx8m(void)
> +{
> + if (current_el() != 3)
> + return;
> +
> + relocate_to_current_adr();
If I use:
extern char early_imx8m_vectors[];
addr = runtime_address(early_imx8m_vectors);
it does work without relocation too. This seems to fit better here. I
will send a v2 if you're okay with that.
Regards,
Marco
> +
> + asm volatile("msr vbar_el3, %0" : : "r" (&early_imx8m_vectors) : "cc");
> + asm volatile("msr daifclr, #4;isb");
> +}
