[U-Boot] [PATCH v2 28/29] riscv: qemu: detect and boot the kernel passed by QEMU
Auer, Lukas
lukas.auer at aisec.fraunhofer.de
Sun Nov 4 12:52:04 UTC 2018
On Sat, 2018-11-03 at 20:33 +0100, Alexander Graf wrote:
>
> On 03.11.18 18:07, Auer, Lukas wrote:
> > 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?
>
> I'm not quite sure yet what goes wrong. I tested and verified the
> riscv
> uefi port on andes targets (where at least grub still works), but I
> can
> confirm that the same code just falls apart for me on the qemu
> target.
>
> Any help to debug it down a bit further is much appreciated.
>
I started to narrow it down further. The hello EFI application faults
at the very beginning of its efi_main. The first thing it does is to
print "Hello World". For that, it needs the con_out protocol from the
systable. This is where it goes wrong. con_out is listed to be at
0x17ffd8638, which is above the available system memory. Once it is
accessed, the system throws the load access fault.
So, I think something with the relocation of the systable entries does
not work.
Thanks,
Lukas
> > Also note that I completed the list of exception codes in this
> > patch
> > series. U-Boot master will not indicate this exception occurred.
>
> Ah nice, that will definitely help to debug what's going wrong :).
>
>
> Alex
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