Re: [PATCH v2] riscv: mpfs: Read and store FPGA design information on MPFS hardware.

On Tue, 2026-08-18 at 08:48 -0400, Nathan Whitehorn wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you
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> 
> When working with systems with multiple FPGA firmwares, it is
> sometimes
> useful to be able to use the same U-Boot and script conditional
> behavior
> based on the FPGA firmware ID and version number. This, allows, for
> example, flashing new FPGA images without flashing the bootloader and
> letting U-Boot and the Linux kernel adapt appropriately.
> 
> This does two things with the information:
> 1. Prints the FPGA design ID and version to the console as part of U-
> Boot
>    startup, which is helpful to a human working with the board.
> 2. Stores the same information, plus the already-acquired FPGA serial
>    number, in a new set of environment variables (serial_number,
>    design_id, design_ver [the version], and design_backlevel
>    [minimum-version backlevel]). These can be used in a U-Boot script
> to
>    load different kernels, device trees, etc. depending on the
> currently
>    installed firmware, which allows U-Boot and the kernel to adapt
>    cleanly to FPGA firmware updates that change accessible
> peripherals
>    etc.
> 
> Signed-off-by: Nathan Whitehorn <[email protected]>
> ---
> Changes for v2:
> - Rename environment variables to remove the pf_ prefix
> - Remove portions of the patch that added properties to the device
> tree
> - Style changes
> - Rebase after a5f93037f28624c612288e2d97604d73e03af5a3
> 
> Thanks to Conor Dooley and Tim Ouyang for helpful suggestions.
> 
>  board/microchip/mpfs_generic/mpfs_generic.c | 26 ++++++++++
>  drivers/misc/mpfs_syscontroller.c           | 54
> +++++++++++++++++++++
>  include/mpfs-mailbox.h                      |  2 +
>  3 files changed, 82 insertions(+)
> 
Hi Nathan,

Happy with the patch other than Conor's styling suggestions and one NIK
of my own seen below..

Other than those:
Acked-by: Jamie Gibbons <[email protected]>

Thanks for the patch.
> diff --git a/board/microchip/mpfs_generic/mpfs_generic.c
> b/board/microchip/mpfs_generic/mpfs_generic.c
> index f57f5f4046b..4423dd1e38c 100644
> --- a/board/microchip/mpfs_generic/mpfs_generic.c
> +++ b/board/microchip/mpfs_generic/mpfs_generic.c
> @@ -114,7 +114,10 @@ int board_late_init(void)
>  {
>         u32 ret;
>         int node;
> +       int idx;
>         u8 device_serial_number[16] = {0};
> +       char serialstring[33], designid[33];
> +       u16 designver, designbacklevel;
>         void *blob = (void *)gd->fdt_blob;
>         struct udevice *dev;
>         struct mpfs_sys_serv *sys_serv_priv;
> @@ -144,6 +147,29 @@ int board_late_init(void)
>                 return -EINVAL;
>         }
> 
> +       /* Store design info and serial number in environment */
> +       memset(designid, 0, sizeof(designid));
> +       memset(serialstring, 0, sizeof(serialstring));
> +
> +       ret = mpfs_syscontroller_read_design_info(sys_serv_priv,
> designid,
> +                       &designver, &designbacklevel);
> +       if (ret) {
> +               printf("Cannot read device design information\n");
> +               return -EINVAL;
> +       }
> +       for (idx = 0; idx < 16; idx++)
> +               sprintf(&serialstring[2*idx], "%02x",
> device_serial_number[idx]);
> +
> +       env_set("serial_number", serialstring);
> +       env_set("design_id", designid);
> +       env_set_ulong("design_ver", designver);
> +       env_set_ulong("design_backlevel", designbacklevel);
> +
> +       printf("FPGA Design name: %s\n", designid);
> +       printf("FPGA Serial: %s\n", serialstring);
> +       printf("Design version number %d (backlevel %d)\n",
> designver,
> +                       designbacklevel);
> +
>         /* Update MAC address with device serial number */
>         mac_addr[0] = 0x00;
>         mac_addr[1] = 0x04;
> diff --git a/drivers/misc/mpfs_syscontroller.c
> b/drivers/misc/mpfs_syscontroller.c
> index b9aea7e1181..07a788db76e 100644
> --- a/drivers/misc/mpfs_syscontroller.c
> +++ b/drivers/misc/mpfs_syscontroller.c
> @@ -152,6 +152,60 @@ int mpfs_syscontroller_read_sernum(struct
> mpfs_sys_serv *sys_serv_priv, u8 *devi
>  }
>  EXPORT_SYMBOL(mpfs_syscontroller_read_sernum);
> 
> +/**
> + * mpfs_syscontroller_read_design_info() - Use system service to
> read FPGA design info
> + * @sys_serv_priv:     system service private data
> + * @designid:          30-byte string name of top module in FPGA
> logic design
> + *                     NB: null termination is not guaranteed
> + * @designver:         version number of the FPGA design
> + * @backlevel:         programmed minimum allowed FPGA design
> version
> + *
> + * Return: 0 if all went ok, else return appropriate error
> + */
> +int mpfs_syscontroller_read_design_info(struct mpfs_sys_serv
> *sys_serv_priv,
> +               u8 *designid, u16 *designver, u16 *backlevel)
> +{
> +       unsigned long timeoutsecs = 300;
> +       u8 data[36];
> +       int ret;
> +
> +       struct mpfs_mss_response response = {
> +               .resp_status = 0U,
> +               .resp_msg = (u32 *)data,
> +               .resp_size = sizeof(data)};
> +       struct mpfs_mss_msg msg = {
> +               .cmd_opcode = 2,
Could you put this as a define at the top of the file with the others
instead of having it hardcoded here please.

Thanks,
Jamie.
> +               .cmd_data_size = CMD_DATA_SIZE,
> +               .response = &response,
> +               .cmd_data = CMD_DATA,
> +               .mbox_offset = MBOX_OFFSET,
> +               .resp_offset = RESP_OFFSET};
> +
> +       ret = mpfs_syscontroller_run_service(sys_serv_priv-
> >sys_controller, &msg);
> +       if (ret) {
> +               dev_err(sys_serv_priv->sys_controller->chan.dev,
> "Service failed: %d, abort\n", ret);
> +               return ret;
> +       }
> +
> +       /* Receive the response */
> +       ret = mpfs_syscontroller_recv_response(sys_serv_priv-
> >sys_controller, &msg, timeoutsecs);
> +       if (ret)
> +               return ret;
> +
> +       debug("%s: Read successful %s\n",
> +             __func__, sys_serv_priv->sys_controller->chan.dev-
> >name);
> +
> +       if (designid != NULL)
> +               memcpy(designid, &data[2], 30);
> +       if (designver != NULL)
> +               memcpy(designver, &data[32], 2);
> +       if (backlevel != NULL)
> +               memcpy(backlevel, &data[34], 2);
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL(mpfs_syscontroller_read_design_info);
> +
>  static u16 mpfs_syscontroller_service_spi_copy(struct mpfs_sys_serv
> *sys_serv_priv, u64 dst_addr, u32 src_addr, u32 length)
>  {
>         int ret;
>