Add support for state and barebox environment by applying an overlay on
top of the qemu generated device tree. If qemu is used with a persistent
flash partition, this allows usage of environments and state across qemu
reboots.
Simple testing can be performed by starting with
qemu-system-arm -m 256M -M virt -kernel images/barebox-dt-2nd.img -nographic
Storing data, changing into the qemu console via Ctrl-A Ctrl-C, issuing
'system_reset' and Ctrl-A Ctrl-C to get back into the barebox console.
Signed-off-by: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx>
---
arch/arm/boards/qemu-virt/.gitignore | 1 +
arch/arm/boards/qemu-virt/Makefile | 1 +
arch/arm/boards/qemu-virt/board.c | 34 +++++++
.../arm/boards/qemu-virt/overlay-of-flash.dts | 97 +++++++++++++++++++
arch/arm/configs/vexpress_defconfig | 1 +
arch/arm/mach-vexpress/Kconfig | 1 +
6 files changed, 135 insertions(+)
create mode 100644 arch/arm/boards/qemu-virt/.gitignore
create mode 100644 arch/arm/boards/qemu-virt/overlay-of-flash.dts
diff --git a/arch/arm/boards/qemu-virt/.gitignore b/arch/arm/boards/qemu-virt/.gitignore
new file mode 100644
index 0000000000..5d65b54bf1
--- /dev/null
+++ b/arch/arm/boards/qemu-virt/.gitignore
@@ -0,0 +1 @@
+*.dtb*
diff --git a/arch/arm/boards/qemu-virt/Makefile b/arch/arm/boards/qemu-virt/Makefile
index dcfc2937d3..8451c7832d 100644
--- a/arch/arm/boards/qemu-virt/Makefile
+++ b/arch/arm/boards/qemu-virt/Makefile
@@ -1 +1,2 @@
obj-y += board.o
+obj-y += overlay-of-flash.dtb.o
diff --git a/arch/arm/boards/qemu-virt/board.c b/arch/arm/boards/qemu-virt/board.c
index 3aeea1a017..9d8c90eb5b 100644
--- a/arch/arm/boards/qemu-virt/board.c
+++ b/arch/arm/boards/qemu-virt/board.c
@@ -5,7 +5,41 @@
*/
#include <common.h>
#include <init.h>
+#include <of.h>
#include <asm/system_info.h>
+#include <asm/barebox-arm.h>
+
+extern char __dtb_overlay_of_flash_start[];
+
+static int replace_dtb(void) {
+ struct device_node *overlay;
+ void *fdt;
+ struct device_node *root;
+
+ fdt = barebox_arm_boot_dtb();
+ if (fdt)
+ pr_debug("using boarddata provided DTB\n");
+
+ if (!fdt) {
+ pr_debug("No DTB found\n");
+ return 0;
+ }
+
+ root = of_unflatten_dtb(fdt);
+
+ if (!of_device_is_compatible(root, "linux,dummy-virt")) {
+ of_delete_node(root);
+ return 0;
+ }
+
+ overlay = of_unflatten_dtb(__dtb_overlay_of_flash_start);
+ of_overlay_apply_tree(root, overlay);
+ barebox_register_of(root);
+
+ return 0;
+}
+
+pure_initcall(replace_dtb);
static int virt_probe(struct device_d *dev)
{
diff --git a/arch/arm/boards/qemu-virt/overlay-of-flash.dts b/arch/arm/boards/qemu-virt/overlay-of-flash.dts
new file mode 100644
index 0000000000..e00dc5d7e2
--- /dev/null
+++ b/arch/arm/boards/qemu-virt/overlay-of-flash.dts
@@ -0,0 +1,97 @@
+/dts-v1/;
+/plugin/;
+/ {
+ fragment@0 {
+ target-path = "/flash@0";
+ __overlay__ {
+ partitions {
+ compatible = "fixed-partitions";
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ partition@0 {
+ label = "initramfs";
+ reg = <0x0 0x3c00000>;
+ };
+
+ environment_flash: partition@3c00000 {
+ label = "barebox-environment";
+ reg = <0x3c00000 0x200000>;
+ };
+
+ backend_state_flash: partition@3e00000 {
+ label = "barebox-state";
+ reg = <0x3e00000 0x200000>;
+ };
+ };
+ };
+ };
+ fragment@1 {
+ target-path="/";
+ __overlay__ {
+ chosen {
+ environment {
+ compatible = "barebox,environment";
+ device-path = "/flash@0/partitions/partition@3c00000";
+ };
+ };
+ aliases {
+ state = "/state";
+ };
+
+ state {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "barebox,state";
+ magic = <0x290cf8c6>;
+ backend-type = "raw";
+ backend = < &backend_state_flash >;
+ backend-stridesize = <0x200>;
+
+ bootstate {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ system0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ remaining_attempts@0 {
+ reg = <0x0 0x4>;
+ type = "uint32";
+ default = <3>;
+ };
+
+ priority@4 {
+ reg = <0x4 0x4>;
+ type = "uint32";
+ default = <20>;
+ };
+ };
+
+ system1 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ remaining_attempts@8 {
+ reg = <0x8 0x4>;
+ type = "uint32";
+ default = <3>;
+ };
+
+ priority@c {
+ reg = <0xc 0x4>;
+ type = "uint32";
+ default = <21>;
+ };
+ };
+
+ last_chosen@10 {
+ reg = <0x10 0x4>;
+ type = "uint32";
+ };
+ };
+ };
+ };
+ };
+};
diff --git a/arch/arm/configs/vexpress_defconfig b/arch/arm/configs/vexpress_defconfig
index f17af2bb95..760e39b440 100644
--- a/arch/arm/configs/vexpress_defconfig
+++ b/arch/arm/configs/vexpress_defconfig
@@ -50,6 +50,7 @@ CONFIG_NET=y
CONFIG_NET_NFS=y
CONFIG_NET_NETCONSOLE=y
CONFIG_OF_BAREBOX_DRIVERS=y
+CONFIG_OF_OVERLAY=y
CONFIG_SERIAL_AMBA_PL011=y
CONFIG_DRIVER_NET_SMC91111=y
# CONFIG_SPI is not set
diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig
index 9d301f7ae8..557c9653f4 100644
--- a/arch/arm/mach-vexpress/Kconfig
+++ b/arch/arm/mach-vexpress/Kconfig
@@ -11,5 +11,6 @@ config MACH_VIRT
bool "QEMU virt"
select ARM_PSCI_CLIENT
select BOARD_ARM_GENERIC_DT
+ select OF_OVERLAY
endif
--
2.29.2
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