target/linux/bcm27xx/patches-5.10/950-0447-ARM-dts-bcm2711-Add-reserved-memory-template-to-hold.patch

   1 From b3a070cf6fe04129d2c174e45c14b98a759e0402 Mon Sep 17 00:00:00 2001
   2 From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
   3 Date: Fri, 11 Dec 2020 12:22:01 +0100
   4 Subject: [PATCH] ARM: dts: bcm2711: Add reserved memory template to
   5  hold firmware configuration
   6
   7 RPi4's co-processor will copy the board's bootloader[1] configuration
   8 into memory for the OS to consume. Specifically, for the bootloader
   9 configuration and upgrade user-space routines to query it through
  10 nvmem's sysfs interface.
  11
  12 Introduce a reserved-memory area template for the co-processor to edit
  13 before booting the system so as for Linux not to overwrite that memory
  14 and to expose it as an nvmem device.
  15
  16 Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
  17
  18 [1] https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md
  19 ---
  20
  21 Changes since v1:
  22  - Introduce compatible string
  23  - Change alias name to something more explicit
  24 ---
  25  arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 17 +++++++++++++++++
  26  1 file changed, 17 insertions(+)
  27
  28 --- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
  29 +++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
  30 @@ -24,6 +24,7 @@
  31                 emmc2bus = &emmc2bus;
  32                 ethernet0 = &genet;
  33                 pcie0 = &pcie0;
  34 +               blconfig = &blconfig;
  35         };
  36
  37         leds {
  38 @@ -215,6 +216,22 @@
  39         status = "okay";
  40  };
  41
  42 +&rmem {
  43 +       /*
  44 +        * RPi4's co-processor will copy the board's bootloader configuration
  45 +        * into memory for the OS to consume. It'll also update this node with
  46 +        * its placement information.
  47 +        */
  48 +       blconfig: nvram@0 {
  49 +               compatible = "raspberrypi,bootloader-config", "nvmem-rmem";
  50 +               #address-cells = <1>;
  51 +               #size-cells = <1>;
  52 +               reg = <0x0 0x0 0x0>;
  53 +               no-map;
  54 +               status = "disabled";
  55 +       };
  56 +};
  57 +
  58  /* SDHCI is used to control the SDIO for wireless */
  59  &sdhci {
  60         #address-cells = <1>;