[RFC PATCH 19/20] boot: bootmeth: openwrt: add openwrt_boot_script hook for bootconf

[Daniel Golle]

Some boards need to probe hardware at boot time to determine the
correct FIT configuration. For example, the BPi-R3 checks whether
SPI-NAND or SPI-NOR is present and selects the matching FIT config
overlay accordingly.

Add an optional script hook: if the environment variable
openwrt_boot_script is set, its content is executed as a U-Boot
command string right before bootconf is read. This lets board
configurations assemble the correct bootconf value dynamically:

  setenv openwrt_boot_script 'if nand info; then
    setenv bootconf $bootconf_base#$bootconf_emmc#$bootconf_nand;
  else
    setenv bootconf $bootconf_base#$bootconf_emmc#$bootconf_nor;
  fi'

The hook runs once per boot attempt, after the image loader is set up
but before bootm_run() is called.

Signed-off-by: Daniel Golle <daniel at makrotopia.org>
---
 boot/bootmeth_openwrt.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/boot/bootmeth_openwrt.c b/boot/bootmeth_openwrt.c
index e1f47b58f61..d448697fe08 100644
--- a/boot/bootmeth_openwrt.c
+++ b/boot/bootmeth_openwrt.c
@@ -12,6 +12,7 @@
 #include <bootflow.h>
 #include <bootm.h>
 #include <bootmeth.h>
+#include <command.h>
 #include <dm.h>
 #include <env.h>
 #include <image.h>
@@ -113,6 +114,17 @@ static int openwrt_boot(struct udevice *dev, struct bootflow *bflow)
 	bootm_init(&bmi);
 	bmi.loader = &ldr;
 
+	/*
+	 * Optional script hook: run the command in openwrt_boot_script
+	 * before reading bootconf. Boards use this to probe hardware
+	 * and assemble the correct FIT configuration string, e.g.:
+	 *
+	 *   setenv openwrt_boot_script 'if nand info; then ...'
+	 */
+	conf = env_get("openwrt_boot_script");
+	if (conf)
+		run_command(conf, 0);
+
 	/* FIT config selection via #conf suffix */
 	conf = env_get("bootconf");
 	if (conf) {
-- 
2.53.0