boot: Move extension board support from cmd/ to boot/

Relocate extension board support from cmd/ to boot/ directory in
preparation for converting the extension framework to use UCLASS.
Also improve code style by applying reverse xmas tree ordering.

Signed-off-by: Kory Maincent (TI.com) <[email protected]>

3 files changed, 104 insertions, 0 deletions

diff --git a/boot/Kconfig b/boot/Kconfig
index dd047365754..a75f6b641ed 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -1906,6 +1906,10 @@ endmenu
 
 endif # OF_LIBFDT
 
+config SUPPORT_EXTENSION_SCAN
+	select OF_LIBFDT_OVERLAY
+        bool
+
 config USE_BOOTARGS
 	bool "Enable boot arguments"
 	help
diff --git a/boot/Makefile b/boot/Makefile
index 3da6f7a0914..f60d13130b1 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_BOOT_RETRY) += bootretry.o
 obj-$(CONFIG_CMD_BOOTM) += bootm.o bootm_os.o
 obj-$(CONFIG_CMD_BOOTZ) += bootm.o bootm_os.o
 obj-$(CONFIG_CMD_BOOTI) += bootm.o bootm_os.o
+obj-$(CONFIG_SUPPORT_EXTENSION_SCAN) += extension.o
 
 obj-$(CONFIG_PXE_UTILS) += pxe_utils.o
 
diff --git a/boot/extension.c b/boot/extension.c
new file mode 100644
index 00000000000..8f28a7e1626
--- /dev/null
+++ b/boot/extension.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2025 Köry Maincent <[email protected]>
+ */
+
+#include <bootdev.h>
+#include <command.h>
+#include <env.h>
+#include <extension_board.h>
+#include <fdt_support.h>
+#include <malloc.h>
+#include <mapmem.h>
+
+LIST_HEAD(extension_list);
+
+int extension_apply(struct extension *extension)
+{
+	ulong extrasize, overlay_addr;
+	struct fdt_header *blob;
+	char *overlay_cmd;
+
+	if (!working_fdt) {
+		printf("No FDT memory address configured. Please configure\n"
+		       "the FDT address via \"fdt addr <address>\" command.\n");
+		return CMD_RET_FAILURE;
+	}
+
+	overlay_cmd = env_get("extension_overlay_cmd");
+	if (!overlay_cmd) {
+		printf("Environment extension_overlay_cmd is missing\n");
+		return CMD_RET_FAILURE;
+	}
+
+	overlay_addr = env_get_hex("extension_overlay_addr", 0);
+	if (!overlay_addr) {
+		printf("Environment extension_overlay_addr is missing\n");
+		return CMD_RET_FAILURE;
+	}
+
+	env_set("extension_overlay_name", extension->overlay);
+	if (run_command(overlay_cmd, 0) != 0)
+		return CMD_RET_FAILURE;
+
+	extrasize = env_get_hex("filesize", 0);
+	if (!extrasize)
+		return CMD_RET_FAILURE;
+
+	fdt_shrink_to_minimum(working_fdt, extrasize);
+
+	blob = map_sysmem(overlay_addr, 0);
+	if (!fdt_valid(&blob))
+		return CMD_RET_FAILURE;
+
+	/* apply method prints messages on error */
+	if (fdt_overlay_apply_verbose(working_fdt, blob))
+		return CMD_RET_FAILURE;
+
+	return CMD_RET_SUCCESS;
+}
+
+int extension_scan(bool show)
+{
+	struct extension *extension, *next;
+	int extension_num;
+
+	list_for_each_entry_safe(extension, next, &extension_list, list) {
+		list_del(&extension->list);
+		free(extension);
+	}
+	extension_num = extension_board_scan(&extension_list);
+	if (show && extension_num >= 0)
+		printf("Found %d extension board(s).\n", extension_num);
+
+	/* either the number of extensions, or -ve for error */
+	return extension_num;
+}
+
+static int extension_bootdev_hunt(struct bootdev_hunter *info, bool show)
+{
+	int ret;
+
+	ret = env_set_hex("extension_overlay_addr",
+			  env_get_hex("fdtoverlay_addr_r", 0));
+	if (ret)
+		return log_msg_ret("env", ret);
+
+	ret = extension_scan(show);
+	if (ret < 0)
+		return log_msg_ret("ext", ret);
+
+	return 0;
+}
+
+/* extensions should have a uclass - for now we use UCLASS_SIMPLE_BUS uclass */
+BOOTDEV_HUNTER(extension_bootdev_hunter) = {
+	.prio		= BOOTDEVP_1_PRE_SCAN,
+	.uclass		= UCLASS_SIMPLE_BUS,
+	.hunt		= extension_bootdev_hunt,
+};