[Buildroot] [PATCH v2 5/5] boot: riscv: Initial commit of OpenSBI

[Thomas Petazzoni <thomas.petazzoni@bootlin.com>]

Hello Alistair,

On Mon, 18 Mar 2019 21:02:04 +0000
Alistair Francis <Alistair.Francis@wdc.com> wrote:

> OpenSBI is a much improved alternative to BBL (riscv-pk). Add OpenSBI
> support to buildroot.
> 
> OpenSBI is also set as the default boot loader for RISC-V.
> 
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

This should be two separate commits:

 - One adding boot/opensbi/ as a new package

 - One updating the defconfig to use opensbi (and the new Image kernel
   format)

So overall, you should have the following commits:

	linux: allow BR2_LINUX_KERNEL_IMAGE on RISC-V
	boot/opensbi: new package
	configs/qemu_riscv*_virt: use opensbi instead of riscv-pk


>  N:	Alvaro G. M <alvaro.gamez@hazent.com>
> diff --git a/board/qemu/riscv32-virt/readme.txt b/board/qemu/riscv32-virt/readme.txt
> index 2da99580e5..f73f4278de 100644
> --- a/board/qemu/riscv32-virt/readme.txt
> +++ b/board/qemu/riscv32-virt/readme.txt
> @@ -1,7 +1,11 @@
> -Run the emulation with:
> +Run Linux in emulation with:
>  
> -  qemu-system-riscv32 -M virt -kernel output/images/bbl -append "root=/dev/vda ro console=ttyS0" -drive file=output/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -netdev user,id=net0 -device virtio-net-device,netdev=net0 -nographic
> +  qemu-system-riscv32 -M virt -kernel output/images/fw_jump.elf -device loader,file=output/images/Image,addr=0x80400000 -append "root=/dev/vda ro console=ttyS0" -drive file=output/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -netdev user,id=net0 -device virtio-net-device,netdev=net0 -nographic
>  
>  The login prompt will appear in the terminal that started Qemu.
>  
> -Tested with QEMU 2.12.1
> +It is also possible to boot u-boot in QEMU. Although at the time of testing there were some issues with the OpenSBI to u-boot hand off. Run u-boot in emulation with:
> +
> +  qemu-system-riscv32 -M virt -kernel output/images/fw_jump.elf -device loader,file=output/images/u-boot,addr=0x80400000 -append "root=/dev/vda ro console=ttyS0" -drive file=output/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -netdev user,id=net0 -device virtio-net-device,netdev=net0 -nographic

The defconfig is not building U-Boot for RISC-V, so this part is not
relevant in this readme.txt.

> +It is also possible to boot u-boot in QEMU. Although at the time of testing there were some issues with the OpenSBI to u-boot hand off. Run u-boot in emulation with:
> +
> +  qemu-system-riscv64 -M virt -kernel output/images/fw_jump.elf -device loader,file=output/images/u-boot,addr=0x80200000 -append "root=/dev/vda ro console=ttyS0" -drive file=output/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -netdev user,id=net0 -device virtio-net-device,netdev=net0 -nographic

Ditto.

> diff --git a/boot/opensbi/Config.in b/boot/opensbi/Config.in
> new file mode 100644
> index 0000000000..65d39aa664
> --- /dev/null
> +++ b/boot/opensbi/Config.in
> @@ -0,0 +1,23 @@
> +config BR2_TARGET_OPENSBI
> +	bool "opensbi"
> +	depends on BR2_riscv
> +	help
> +	  OpenSBI aims to provide an open-source and extensible
> +	  implementation of the RISC-V SBI specification for a platform
> +	  specific firmware (M-mode) and a general purpose OS, hypervisor
> +	  or bootloader (S-mode or HS-mode). OpenSBI implementation can
> +	  be easily extended by RISC-V platform or System-on-Chip vendors
> +	  to fit a particular hadware configuration.
> +
> +	  https://github.com/riscv/opensbi.git
> +
> +if BR2_TARGET_OPENSBI
> +config BR2_TARGET_OPENSBI_PLAT
> +	string "OpenSBI Platform"
> +	default ""
> +	help
> +	  Specifies the OpenSBI platform to build. If no platform is specified only
> +	  the OpenSBI platform independent static library libsbi.a is built. If a
> +	  platform is specified then the platform specific static library libplatsbi.a
> +	  and firmware examples are built.

I'm pretty sure "make check-package" would whine here about the lines
being too long. Could you make sure to run "make check-package" before
your next submission ?

> +OPENSBI_PLAT = $(call qstrip,$(BR2_TARGET_OPENSBI_PLAT))
> +ifneq ($(OPENSBI_PLAT),)
> +	OPENSBI_MAKE_ENV += PLATFORM=$(OPENSBI_PLAT)

No indentation here.

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com