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

[Auer, Lukas]

On Tue, 2018-11-13 at 10:01 +0100, Alexander Graf wrote:
> 
> 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?
> 

Thank you! I am not the only one using board-specific boot commands
however, I saw it used on sunxi with the FEL boot command. :)
Yes, I think that would make sense, even if it is just to move shared
targets into a common file and make them more reusable. There seems to
also be a lot of code duplication from config_distro_common.h in the
NXP LS board files, which can probably be removed.

Lukas

> 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" \
> >