Re: [PATCH] ASoC: SOF: amd: Load alternatively signed firmware with an "_l" suffix

["Péter Ujfalusi" <peter.ujfalusi@linux.intel.com>]

On 04/11/2026 23:53, Mario Limonciello wrote:
> Platforms ship BIOS with either a default or an alternative trust
> authority. The PSP validates the signed DSP firmware image so it must
> be signed with the matching scheme. Firmware for the alternative scheme
> is named with an "_l" suffix before the extension
> (e.g. "sof-X-code.bin" becomes "sof-X-code_l.bin").
> 
> The PSP reports the signing type in bit 6 of C2PMSG_63
> (0 = default, 1 = alternative). Read it over SMN, as is already done
> for the other PSP mailbox registers, when building the signed code
> image name, and add the "_l" suffix for the alternative scheme.
> 
> Reviewed-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  sound/soc/sof/amd/acp.c | 33 ++++++++++++++++++++++++++++++++-
>  sound/soc/sof/amd/acp.h |  2 ++
>  2 files changed, 34 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/soc/sof/amd/acp.c b/sound/soc/sof/amd/acp.c
> index 86e2402b8ffd2..2f1a8be8460d4 100644
> --- a/sound/soc/sof/amd/acp.c
> +++ b/sound/soc/sof/amd/acp.c
> @@ -1212,6 +1212,31 @@ static int amd_sof_sdw_exit(struct snd_sof_dev *sdev)
>  }
>  #endif
>  
> +/*
> + * The PSP validates the signed DSP firmware, so it must be signed with the
> + * scheme the platform firmware uses: images for the alternative scheme are
> + * named with an "_l" suffix before the extension, the default ones have none.
> + */
> +static int amd_sof_acp_get_fw_suffix(struct snd_sof_dev *sdev, const char **suffix)
> +{
> +	u32 val;
> +	int ret;
> +
> +	ret = amd_smn_read(0, MP0_C2PMSG_63_REG, &val);
> +	if (ret) {
> +		dev_err(sdev->dev, "failed to read PSP firmware signing type: %d\n", ret);

I would read this in case of error as the signing type is -22 (or
whatever the error code returned is)

> +		return ret;
> +	}
> +
> +	/* all ones means the register isn't accessible */
> +	if (val == 0xffffffff)
> +		return -EIO;

this would also merit an error print?

> +
> +	*suffix = (val & MP0_C2PMSG_63_FW_SIGN_ALT) ? "_l" : "";
> +
> +	return 0;
> +}
> +
>  int amd_sof_acp_probe(struct snd_sof_dev *sdev)
>  {
>  	struct pci_dev *pci = to_pci_dev(sdev->dev);
> @@ -1448,8 +1473,14 @@ int amd_sof_acp7x_probe(struct snd_sof_dev *sdev)
>  	sdev->debug_box.size = BOX_SIZE_1024;
>  
>  	if (adata->acp_sof_signed_firmware_image) {
> +		const char *fw_suffix;
> +
> +		ret = amd_sof_acp_get_fw_suffix(sdev, &fw_suffix);
> +		if (ret)
> +			goto free_ipc_irq;
> +
>  		adata->fw_code_bin = devm_kasprintf(sdev->dev, GFP_KERNEL,
> -						    "sof-%s-code.bin", chip->name);
> +						    "sof-%s-code%s.bin", chip->name, fw_suffix);
>  		if (!adata->fw_code_bin) {
>  			ret = -ENOMEM;
>  			goto free_ipc_irq;
> diff --git a/sound/soc/sof/amd/acp.h b/sound/soc/sof/amd/acp.h
> index b17a36b31ee0d..81eeeabc5cf5c 100644
> --- a/sound/soc/sof/amd/acp.h
> +++ b/sound/soc/sof/amd/acp.h
> @@ -97,6 +97,8 @@
>  #define ACP_EXT_INTR_ERROR_STAT			0x20000000
>  #define MP0_C2PMSG_114_REG			0x3810AC8
>  #define MP0_C2PMSG_73_REG			0x3810A24
> +#define MP0_C2PMSG_63_REG			0x38109FC
> +#define MP0_C2PMSG_63_FW_SIGN_ALT		BIT(6)
>  #define MBOX_ACP_SHA_DMA_COMMAND		0x70000
>  #define MBOX_ACP_IRAM_DRAM_FENCE_COMMAND	0x80000
>  #define MBOX_DELAY_US				1000
> 
> ---
> base-commit: 68e9934bd17af558b62cac8a444de28d4d5cdb9f
> change-id: 20261104-superm1-lms-sound-c0f429351fc7
> 
> Best regards,
> --  
> Mario Limonciello <mario.limonciello@amd.com>

-- 
Péter