[U-Boot] [PATCH v3 27/28] riscv: qemu: detect and boot the kernel passed by QEMU

[Alexander Graf]

On 09.11.18 13:59, Lukas Auer wrote:
> QEMU embeds the location of the kernel image in the device tree. Store
> this address in the environment as variable kernel_start. It is used in
> the board-local distro boot command QEMU to boot the kernel with the
> U-Boot device tree. The QEMU boot command is added as the first boot
> target device.
> 
> Signed-off-by: Lukas Auer <lukas.auer at aisec.fraunhofer.de>

That is a very elegant solution to the problem :). Awesome. Maybe we
should consider to move to board specific distro targets for things like
the NXP LS legacy flash boot as well?

Reviewed-by: Alexander Graf <agraf at suse.de>


Alex

> ---
> 
> Changes in v3:
> - Adapt code and commit message to distro boot
> - Replace printf with debug
> - Clarify debug messages if no chosen node is found
> 
> Changes in v2:
> - Rebase onto u-boot-dm/next
> - Boot Linux with the device tree provided by the prior boot stage
> 
>  board/emulation/qemu-riscv/Kconfig      |  1 +
>  board/emulation/qemu-riscv/qemu-riscv.c | 29 +++++++++++++++++++++++++
>  include/configs/qemu-riscv.h            | 10 +++++++++
>  3 files changed, 40 insertions(+)
> 
> diff --git a/board/emulation/qemu-riscv/Kconfig b/board/emulation/qemu-riscv/Kconfig
> index 37a80db6a9..be5839b7db 100644
> --- a/board/emulation/qemu-riscv/Kconfig
> +++ b/board/emulation/qemu-riscv/Kconfig
> @@ -29,5 +29,6 @@ config BOARD_SPECIFIC_OPTIONS # dummy
>  	imply CMD_EXT2
>  	imply CMD_EXT4
>  	imply CMD_FAT
> +	imply BOARD_LATE_INIT
>  
>  endif
> diff --git a/board/emulation/qemu-riscv/qemu-riscv.c b/board/emulation/qemu-riscv/qemu-riscv.c
> index 2ce093e19a..587f2c4909 100644
> --- a/board/emulation/qemu-riscv/qemu-riscv.c
> +++ b/board/emulation/qemu-riscv/qemu-riscv.c
> @@ -19,3 +19,32 @@ int board_init(void)
>  
>  	return 0;
>  }
> +
> +int board_late_init(void)
> +{
> +	ulong kernel_start;
> +	ofnode chosen_node;
> +	int ret;
> +
> +	chosen_node = ofnode_path("/chosen");
> +	if (!ofnode_valid(chosen_node)) {
> +		debug("No chosen node found, can't get kernel start address\n");
> +		return 0;
> +	}
> +
> +#ifdef CONFIG_ARCH_RV64I
> +	ret = ofnode_read_u64(chosen_node, "riscv,kernel-start",
> +			      (u64 *)&kernel_start);
> +#else
> +	ret = ofnode_read_u32(chosen_node, "riscv,kernel-start",
> +			      (u32 *)&kernel_start);
> +#endif
> +	if (ret) {
> +		debug("Can't find kernel start address in device tree\n");
> +		return 0;
> +	}
> +
> +	env_set_hex("kernel_start", kernel_start);
> +
> +	return 0;
> +}
> diff --git a/include/configs/qemu-riscv.h b/include/configs/qemu-riscv.h
> index 66d61bd896..b29d155d09 100644
> --- a/include/configs/qemu-riscv.h
> +++ b/include/configs/qemu-riscv.h
> @@ -21,11 +21,21 @@
>  #define CONFIG_ENV_SIZE			SZ_4K
>  
>  #define BOOT_TARGET_DEVICES(func) \
> +	func(QEMU, qemu, na) \
>  	func(VIRTIO, virtio, 0) \
>  	func(DHCP, dhcp, na)
>  
>  #include <config_distro_bootcmd.h>
>  
> +#define BOOTENV_DEV_QEMU(devtypeu, devtypel, instance) \
> +	"bootcmd_qemu=" \
> +		"if env exists kernel_start; then " \
> +			"bootm ${kernel_start} - ${fdtcontroladdr};" \
> +		"fi;\0"
> +
> +#define BOOTENV_DEV_NAME_QEMU(devtypeu, devtypel, instance) \
> +	"qemu "
> +
>  #define CONFIG_EXTRA_ENV_SETTINGS \
>  	"fdt_high=0xffffffffffffffff\0" \
>  	"initrd_high=0xffffffffffffffff\0" \
>