[U-Boot] [PATCH v2 28/29] riscv: qemu: detect and boot the kernel passed by QEMU

[Auer, Lukas]

On Tue, 2018-10-30 at 16:27 +0100, Alexander Graf wrote:
> 
> On 30.10.18 16:02, Auer, Lukas wrote:
> > On Tue, 2018-10-30 at 13:55 +0100, 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 and use
> > > it
> > > in
> > > CONFIG_BOOTCOMMAND to boot the kernel. Use the device tree passed
> > > by
> > > the
> > > prior boot stage to boot Linux.
> > > 
> > > Signed-off-by: Lukas Auer <lukas.auer at aisec.fraunhofer.de>
> > > ---
> > > 
> > > 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
> > > +++++++++++++++++++++++++
> > >  configs/qemu-riscv32_defconfig          |  1 +
> > >  configs/qemu-riscv64_defconfig          |  1 +
> > >  include/configs/qemu-riscv.h            | 10 ++++++++-
> > >  5 files changed, 41 insertions(+), 1 deletion(-)
> > > 
> > > 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..ee20983095 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)) {
> > > +		printf("No chosen node found\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) {
> > > +		printf("Can't find kernel start address in device
> > > tree\n");
> > > +		return 0;
> > > +	}
> > > +
> > > +	env_set_hex("kernel_start", kernel_start);
> > > +
> > > +	return 0;
> > > +}
> > > diff --git a/configs/qemu-riscv32_defconfig b/configs/qemu-
> > > riscv32_defconfig
> > > index b55644378a..13dd53a550 100644
> > > --- a/configs/qemu-riscv32_defconfig
> > > +++ b/configs/qemu-riscv32_defconfig
> > > @@ -4,4 +4,5 @@ CONFIG_NR_DRAM_BANKS=1
> > >  CONFIG_FIT=y
> > >  CONFIG_DISPLAY_CPUINFO=y
> > >  CONFIG_DISPLAY_BOARDINFO=y
> > > +CONFIG_HUSH_PARSER=y
> > >  CONFIG_OF_PRIOR_STAGE=y
> > > diff --git a/configs/qemu-riscv64_defconfig b/configs/qemu-
> > > riscv64_defconfig
> > > index a542ac4893..06eb3042fa 100644
> > > --- a/configs/qemu-riscv64_defconfig
> > > +++ b/configs/qemu-riscv64_defconfig
> > > @@ -5,4 +5,5 @@ CONFIG_NR_DRAM_BANKS=1
> > >  CONFIG_FIT=y
> > >  CONFIG_DISPLAY_CPUINFO=y
> > >  CONFIG_DISPLAY_BOARDINFO=y
> > > +CONFIG_HUSH_PARSER=y
> > >  CONFIG_OF_PRIOR_STAGE=y
> > > diff --git a/include/configs/qemu-riscv.h b/include/configs/qemu-
> > > riscv.h
> > > index ba6a18f2e6..7c88ba300a 100644
> > > --- a/include/configs/qemu-riscv.h
> > > +++ b/include/configs/qemu-riscv.h
> > > @@ -21,7 +21,15 @@
> > >  #define CONFIG_ENV_SIZE			SZ_4K
> > >  
> > >  #define CONFIG_EXTRA_ENV_SETTINGS \
> > > -	"fdt_high=0xffffffffffffffff\0" \
> > > +	"fdt_high=0x82000000\0" \
> > > +	"bootm_size=0x10000000\0" \
> > >  	"initrd_high=0xffffffffffffffff\0"
> > >  
> > > +#define CONFIG_BOOTCOMMAND \
> > > +	"if env exists kernel_start; then " \
> > > +		"bootm ${kernel_start} - ${prior_stage_dtb};" \
> > 
> > As Alexander Graf pointed out in reply to patch 24, we don't need
> > the
> > separate environment variable "prior_stage_dtb". I will replace it
> > with
> > "fdtcontroladdr" here and drop patch 24 in the next version.
> 
> Also, can you please enable distro boot? :)
> 
> 
> Thanks,
> 
> Alex

I just had a closer look at distro boot and it's actually quite easy to
use. I will update this patch to enable it and will add a bootcmd for
virtio block devices (virtio support is currently in u-boot-dm/next).

I was looking into testing bootefi on U-Boot and tried to run the hello
world and selftest EFI binaries, however I could not get them running.
After starting them I immediately get a load access fault. The faulting
instruction is at 0xfe77c1fa, which is strange since the binary is
loaded to 0x80200000. Do you know what this could be caused by?
Also note that I completed the list of exception codes in this patch
series. U-Boot master will not indicate this exception occurred.

Thanks,
Lukas