Building and running barebox for 32-bit malta:
export ARCH=mips
export CROSS_COMPILE=mips-linux-gnu-
make -s qemu-malta_defconfig
sed -i "s/# \(CONFIG_BOARD_MIPS_GENERIC_DT\) is not set/\1=y/" .config
make -s oldconfig
make -s
qemu-system-mips -M malta -cpu 24Kf -m 256M \
-nographic -serial mon:stdio \
-bios images/barebox-qemu-malta.img \
-net user,tftp=$(pwd) -net nic,model=e1000
Building and running barebox for 64-bit malta:
export ARCH=mips
export CROSS_COMPILE=mips-linux-gnu-
make -s qemu-malta64el_defconfig
sed -i "s/# \(CONFIG_BOARD_MIPS_GENERIC_DT\) is not set/\1=y/" .config
make -s oldconfig
make -s
qemu-system-mips64el -M malta -cpu MIPS64R2-generic -m 256M \
-nographic -serial mon:stdio \
-bios images/barebox-qemu-malta.img.swapped \
-net user,tftp=$(pwd) -net nic,model=e1000
Use bootm to run barebox-dt-2nd.img (external device tree):
barebox@qemu malta:/ dhcp
barebox@qemu malta:/ cp /mnt/tftp/images/barebox-dt-2nd.img barebox.img
barebox@qemu malta:/ cp /mnt/tftp/arch/mips/dts/qemu-malta.dtb .
barebox@qemu malta:/ imd barebox.img
barebox@qemu malta:/ bootm -o qemu-malta.dtb barebox.img
Use bootm to run barebox-qemu-malta.img (encapsulated device tree):
barebox@qemu malta:/ dhcp
barebox@qemu malta:/ cp /mnt/tftp/images/barebox-qemu-malta.img barebox.img
barebox@qemu malta:/ imd barebox.img
barebox@qemu malta:/ bootm barebox.img
N.B. Use just the same commands for both 32-bit and 64-bit malta boards.
Signed-off-by: Antony Pavlov <antonynpavlov@xxxxxxxxx>
---
arch/mips/Kconfig | 10 ++++++++++
arch/mips/boards/Makefile | 2 ++
arch/mips/boards/board-dt-2nd.S | 35 +++++++++++++++++++++++++++++++++
arch/mips/boot/main_entry-pbl.c | 4 ++++
arch/mips/lib/bootm.c | 13 ++++++++++--
5 files changed, 62 insertions(+), 2 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 63ba6aa9d5a..14062dee347 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -319,6 +319,16 @@ config 64BIT
endchoice
+config BOARD_MIPS_GENERIC_DT
+ select BOARD_GENERIC_DT
+ depends on OFDEVICE
+ bool "Build generic MIPS device tree 2nd stage image"
+ help
+ This enables compilation of a generic image that can be started 2nd
+ stage from barebox or from qemu. It picks up a device tree passed
+ in a1 like the Kernel does.
+ The image will be called images/barebox-dt-2nd.img
+
menu "MIPS specific settings"
config CMD_MIPS_CPUINFO
diff --git a/arch/mips/boards/Makefile b/arch/mips/boards/Makefile
index 9402035856c..c4ce599c934 100644
--- a/arch/mips/boards/Makefile
+++ b/arch/mips/boards/Makefile
@@ -13,3 +13,5 @@ obj-$(CONFIG_BOARD_QEMU_MALTA) += qemu-malta/
obj-$(CONFIG_BOARD_RZX50) += ritmix-rzx50/
obj-$(CONFIG_BOARD_TPLINK_MR3020) += tplink-mr3020/
obj-$(CONFIG_BOARD_TPLINK_WDR4300) += tplink-wdr4300/
+
+pbl-$(CONFIG_BOARD_MIPS_GENERIC_DT) += board-dt-2nd.o
diff --git a/arch/mips/boards/board-dt-2nd.S b/arch/mips/boards/board-dt-2nd.S
new file mode 100644
index 00000000000..a1465f09e36
--- /dev/null
+++ b/arch/mips/boards/board-dt-2nd.S
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Startup Code for generic MIPS device tree 2nd stage image
+ *
+ * Copyright (C) 2024 Antony Pavlov <antonynpavlov@xxxxxxxxx>
+ */
+
+#include <asm/asm.h>
+#include <asm/pbl_macros.h>
+#include <linux/sizes.h>
+
+ENTRY_FUNCTION(start_dt_2nd)
+
+ /* save device tree address in v1 */
+ move v1, a1
+
+ mips_cpu_setup
+
+ copy_to_link_location start_dt_2nd
+
+ stack_setup
+
+ /* pbl_main_entry() computes fdt_len by itself
+ * if fdt == fdt_end */
+ move a0, v1 /* fdt */
+ move a1, v1 /* fdt_end */
+ PTR_LI a2, SZ_256M /* ram_size */
+ PTR_LA v0, pbl_main_entry
+ jal v0
+ nop
+
+ /* No return */
+1:
+ b 1b
+ nop
diff --git a/arch/mips/boot/main_entry-pbl.c b/arch/mips/boot/main_entry-pbl.c
index 78982fd995e..389dc94f370 100644
--- a/arch/mips/boot/main_entry-pbl.c
+++ b/arch/mips/boot/main_entry-pbl.c
@@ -11,6 +11,7 @@
#include <asm/sections.h>
#include <asm-generic/memory_layout.h>
#include <debug_ll.h>
+#include <asm/unaligned.h>
extern void *input_data;
extern void *input_data_end;
@@ -45,6 +46,9 @@ void __section(.text_entry) pbl_main_entry(void *fdt, void *fdt_end,
barebox_uncompress(&input_data, piggy_len);
fdt_len = (unsigned long)fdt_end - (unsigned long)fdt;
+ if (!fdt_len) {
+ fdt_len = get_unaligned_be32((void *)((unsigned long)fdt + 4));
+ }
fdt_new = (void *)PAGE_ALIGN_DOWN(TEXT_BASE - MALLOC_SIZE - STACK_SIZE - fdt_len);
memcpy(fdt_new, fdt, fdt_len);
diff --git a/arch/mips/lib/bootm.c b/arch/mips/lib/bootm.c
index 643ad57e4db..86573dec7f1 100644
--- a/arch/mips/lib/bootm.c
+++ b/arch/mips/lib/bootm.c
@@ -16,12 +16,21 @@
static int do_bootm_barebox(struct image_data *data)
{
- void (*barebox)(void);
+ void (*barebox)(int, void *);
+ void *fdt = NULL;
barebox = read_file(data->os_file, NULL);
if (!barebox)
return -EINVAL;
+ if (data->oftree_file) {
+ fdt = bootm_get_devicetree(data);
+ if (IS_ERR(fdt)) {
+ pr_err("Failed to load dtb\n");
+ return PTR_ERR(fdt);
+ }
+ }
+
if (data->dryrun) {
free(barebox);
return 0;
@@ -29,7 +38,7 @@ static int do_bootm_barebox(struct image_data *data)
shutdown_barebox();
- barebox();
+ barebox(-2, fdt);
restart_machine();
}
--
2.39.0
