[PATCH v3] rpi: copy /chosen/bootloader partition and set boot_partition

Gregor Herburger <[email protected]> Tue, 04 Aug 2026 15:39:15 +0200
Newsgroups gmane.comp.boot-loaders.u-boot
Message-ID <[email protected]>
The Raspberry Pi has the "tryboot" feature where it can boot from a
different partition enabling failsafe A/B updates. After boot the
firmware sets 'partition' property in /chosen/bootloader.

Copy the /chosen/bootloader node to the device tree.

Set the env variable boot_partition accordingly to allow boards to
create a bootcmd based on the boot partition.

Reviewed-by: Matthias Brugger <[email protected]>
Signed-off-by: Gregor Herburger <[email protected]>
---
Changes in v3:
- Copy the complete '/chosen/bootloader' node instead of only the
  partition property
- Link to v2: https://patch.msgid.link/[email protected]

Changes in v2:
- update Reviewed-by tag
---
 board/raspberrypi/rpi/rpi.c | 51 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c
index 1da5df92351c..ba8a2c1ba4cf 100644
--- a/board/raspberrypi/rpi/rpi.c
+++ b/board/raspberrypi/rpi/rpi.c
@@ -480,6 +480,20 @@ static void set_serial_number(void)
 	env_set("serial#", serial_string);
 }
 
+static void set_boot_partition_fdt(void)
+{
+	void *fdtp = (void *)gd->fdt_blob;
+	u32 partition;
+
+	partition = fdt_getprop_u32_default(fdtp, "/chosen/bootloader", "partition", 1);
+	if (!partition) {
+		printf("Failed to the get partition property.\n");
+		return;
+	}
+
+	env_set_ulong("boot_partition", partition);
+}
+
 int misc_init_r(void)
 {
 	set_fdt_addr();
@@ -489,6 +503,7 @@ int misc_init_r(void)
 	set_board_info();
 #endif
 	set_serial_number();
+	set_boot_partition_fdt();
 
 	return 0;
 }
@@ -579,6 +594,39 @@ int board_fdt_blob_setup(void **fdtp)
 	return 0;
 }
 
+int copy_node_all_properties(void *dst, void *src, const char *path, const char *node)
+{
+	int src_parent, dst_parent;
+	int src_node, dst_node;
+	int prop;
+	int len;
+
+	src_parent = fdt_path_offset(src, path);
+	dst_parent = fdt_path_offset(dst, path);
+	if (src_parent < 0 || dst_parent < 0)
+		return -1;
+
+	src_node = fdt_subnode_offset(src, src_parent, node);
+	if (src_node < 0)
+		return -1;
+
+	dst_node = fdt_find_or_add_subnode(dst, dst_parent, node);
+	if (dst_node < 0)
+		return -1;
+
+	fdt_for_each_property_offset(prop, src, src_node) {
+		const char *name;
+		const void *value = fdt_getprop_by_offset(src, prop, &name, &len);
+
+		if (!value || !name)
+			continue;
+
+		fdt_setprop(dst, dst_node, name, value, len);
+	}
+
+	return 0;
+}
+
 int copy_property(void *dst, void *src, char *path, char *property)
 {
 	int dst_offset, src_offset;
@@ -641,6 +689,9 @@ void  update_fdt_from_fw(void *fdt, void *fw_fdt)
 
 	/* copy uart clk as provided by the firmware */
 	copy_property(fdt, fw_fdt, "/clocks/clk-uart", "clock-frequency");
+
+	/* Copy the bootloader node */
+	copy_node_all_properties(fdt, fw_fdt, "/chosen", "bootloader");
 }
 
 int ft_board_setup(void *blob, struct bd_info *bd)

---
base-commit: baa64b2f892890f00a377eac4a3e685472bb56b5
change-id: 20260803-tryboot2-8c5221376e5a

Best regards,
--  
Gregor Herburger <[email protected]>