[PATCH 07/12] rockchip: puma-rk3399: load environment from same medium as one used to load U-Boot proper

[Quentin Schulz <foss+uboot@0leil.net>]

From: Quentin Schulz <quentin.schulz@theobroma-systems.com>

Chances are when one boots U-Boot proper from a given storage medium,
they want the same medium to be used to load and store the environment.

This basically allows to have completely separate U-Boot (TPL/SPL/U-Boot
proper/environment) per storage medium which is convenient when working
with recovery from SD-Card as one would just need to insert a properly
configured SD-Card into the device to have access to their whole debug
setup.

No fallback mechanism is provided as to not dirty other storage medium
environment by mistake. However, since arch_env_get_location() is called
by env_init() which is part of the pre-relocation process, a valid,
non-ENVL_UNKNOWN, value shall be returned otherwise the relocation fails
with the following message:
initcall sequence 00000000002866c0 failed at call 0000000000256b34 (err=-19)

This valid, non-ENVL_UNKNOWN, value is ENVL_NOWHERE which requires to
always select CONFIG_ENV_IS_NOWHERE otherwise this work-around does not
work.

Cc: Quentin Schulz <foss+uboot@0leil.net>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
---

Depends on
https://lore.kernel.org/u-boot/20220715151552.953654-1-foss+uboot@0leil.net/
https://lore.kernel.org/u-boot/20220715151552.953654-2-foss+uboot@0leil.net/

 .../puma_rk3399/puma-rk3399.c                 | 37 +++++++++++++++++++
 configs/puma-rk3399_defconfig                 |  1 +
 2 files changed, 38 insertions(+)

diff --git a/board/theobroma-systems/puma_rk3399/puma-rk3399.c b/board/theobroma-systems/puma_rk3399/puma-rk3399.c
index 5e5e58c88e..7ef4bac24b 100644
--- a/board/theobroma-systems/puma_rk3399/puma-rk3399.c
+++ b/board/theobroma-systems/puma_rk3399/puma-rk3399.c
@@ -6,6 +6,7 @@
 #include <common.h>
 #include <dm.h>
 #include <env.h>
+#include <env_internal.h>
 #include <init.h>
 #include <log.h>
 #include <misc.h>
@@ -135,6 +136,42 @@ int mmc_get_env_dev(void)
 	return CONFIG_SYS_MMC_ENV_DEV;
 }
 
+#if !IS_ENABLED(CONFIG_ENV_IS_NOWHERE)
+#error Please enable CONFIG_ENV_IS_NOWHERE
+#endif
+
+enum env_location arch_env_get_location(enum env_operation op, int prio)
+{
+	const char *boot_device =
+		ofnode_read_chosen_string("u-boot,spl-boot-device");
+
+	if (prio > 0)
+		return ENVL_UNKNOWN;
+
+	if (!boot_device) {
+		debug("%s: /chosen/u-boot,spl-boot-device not set\n",
+		      __func__);
+		return ENVL_NOWHERE;
+	}
+
+	debug("%s: booted from %s\n", __func__, boot_device);
+
+	if (IS_ENABLED(CONFIG_ENV_IS_IN_SPI_FLASH) &&
+	    !strcmp(boot_device, "/spi@ff1d0000/flash@0"))
+		return ENVL_SPI_FLASH;
+
+	if (IS_ENABLED(CONFIG_ENV_IS_IN_MMC) &&
+	    (!strcmp(boot_device, "/mmc@fe320000") ||
+	     !strcmp(boot_device, "/mmc@fe330000")))
+		return ENVL_MMC;
+
+	printf("%s: No environment available: booted from %s but U-Boot "
+	       "config does not allow loading environment from it.",
+	       __func__, boot_device);
+
+	return ENVL_NOWHERE;
+}
+
 int misc_init_r(void)
 {
 	const u32 cpuid_offset = 0x7;
diff --git a/configs/puma-rk3399_defconfig b/configs/puma-rk3399_defconfig
index 87d7e4f57c..e218532d70 100644
--- a/configs/puma-rk3399_defconfig
+++ b/configs/puma-rk3399_defconfig
@@ -44,6 +44,7 @@ CONFIG_SPL_OF_CONTROL=y
 CONFIG_OF_LIVE=y
 CONFIG_OF_SPL_REMOVE_PROPS="interrupt-parent assigned-clocks assigned-clock-rates assigned-clock-parents"
 CONFIG_ENV_OVERWRITE=y
+CONFIG_ENV_IS_NOWHERE=y
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_ENV_SPI_MAX_HZ=50000000
-- 
2.37.1