configs: apple: Add custom bootcmd to boot from preferred ESP

AsahiLinux uses a distinct EFI system partition per OS installation 1).
To boot the intended system u-boot has to prefer the intended partition
for booting. The previous stage bootloader specifies in UUID of the
partition in the device tree as "/chosen/asahi,efi-system-partition".
'apple_bootcmd' reads the UUID from the device tree and uses modified
distro boot scripts to only boot from a partition with a matching UUID.
If it fails it tries to boot from the first USB device.

1: https://github.com/AsahiLinux/docs/wiki/Open-OS-Ecosystem-on-Apple-Silicon-Macs

Signed-off-by: Janne Grunau <j@jannau.net>

include/configs/apple.h

@@ -27,8 +27,51 @@
 
 #include <config_distro_bootcmd.h>
 
+#if CONFIG_IS_ENABLED(CMD_NVME) && CONFIG_IS_ENABLED(CMD_USB)
+#define BOOTENV_APPLE                                                          \
+	"scan_dev_for_boot_partuuid="                                          \
+		"part list ${devtype} ${devnum} -bootable devplist; "          \
+		"env exists devplist || setenv devplist 1; "                   \
+		"for distro_bootpart in ${devplist}; do "                      \
+			"part uuid ${devtype} ${devnum}:${distro_bootpart} "   \
+					"partuuid; "                           \
+			"if test U${partuuid} = U${esp_partuuid} ; then "      \
+				"if fstype ${devtype} "                        \
+						"${devnum}:${distro_bootpart} "\
+						"bootfstype; then "            \
+					"run scan_dev_for_boot; "              \
+				"fi; "                                         \
+			"fi; "                                                 \
+		"done; "                                                       \
+		"setenv partuuid; "                                            \
+		"setenv devplist\0" \
+	"nvme_boot_partuuid="                                                  \
+		"run nvme_init; "                                              \
+		"if nvme dev ${devnum}; then "                                 \
+			"devtype=nvme; run scan_dev_for_boot_partuuid;"        \
+		" fi\0" \
+	"bootcmd_apple_nvme0=devnum=0; run nvme_boot_partuuid\0" \
+	"apple_bootcfg="                                                       \
+		"if fdt addr ${fdtcontroladdr}; then "                         \
+			"fdt get value esp_partuuid /chosen asahi,efi-system-partition; "\
+		"fi\0" \
+	"apple_bootcmd="                                                       \
+		"setenv nvme_need_init; run apple_bootcfg; "                   \
+		"if test -n ${esp_partuuid}; then "                            \
+			"run bootcmd_apple_nvme0; "                            \
+			"echo Failed to boot from ESP with UUID ${esp_partuuid}; " \
+			"echo Trying to boot from USB ...; " \
+		"fi; "                                                         \
+		"run bootcmd_usb0; "                                           \
+		"echo Failed to find boot partition `run distro_bootcmd` to boot from any partition\0" \
+	"bootcmd=run apple_bootcmd\0"
+#else
+#define BOOTENV_APPLE
+#endif
+
 #define CONFIG_EXTRA_ENV_SETTINGS \
 	ENV_DEVICE_SETTINGS \
-	BOOTENV
+	BOOTENV \
+	BOOTENV_APPLE
 
 #endif