This series adds support for SPL to RISC-V U-Boot. Images can be booted via OpenSBI (FW_DYNAMIC firmware) or by directly jumping to them. In the former case, OpenSBI and U-Boot proper are bundled as a FIT image and made available to U-Boot SPL. Currently, only the QEMU board enables U-Boot SPL with a dedicated configuration. It uses RAM as SPL boot device.
On many RISC-V CPUs, the device tree is provided to U-Boot by the first stage bootloader. This requires changes to U-Boot SPL (patches 1, 2 and 3), which modify the behavior on other boards as well.
To test this series, OpenSBI has to be compiled first. The fw_dynamic.bin binary must be copied into the U-Boot root directory. Alternatively, the location of the binary can be specified with the OPENSBI environment variable. U-Boot can then be build as normal using the configuration qemu-riscv64_spl_defconfig for 64-bit builds or qemu-riscv32_spl_defconfig for 32-bit builds. The outputs from the build process are the U-Boot SPL binary (spl/u-boot-spl.bin) and the U-Boot FIT image (u-boot.itb) containing U-Boot proper and OpenSBI.
U-Boot can be run in QEMU with the following command.
qemu-system-riscv64 -nographic -machine virt -kernel spl/u-boot-spl \ -device loader,file=u-boot.itb,addr=0x80200000
Changes in v2: - Rebase on master and format documentation as reStructuredText
Lukas Auer (11): fdtdec: make CONFIG_OF_PRIOR_STAGE available in SPL Makefile: support building SPL FIT images without device trees spl: fit: use U-Boot device tree when FIT image has no device tree riscv: add run mode configuration for SPL spl: support booting via RISC-V OpenSBI riscv: add SPL support riscv: support SPL stack and global data relocation riscv: add a generic FIT generator script riscv: set default FIT generator script and build target for SPL builds riscv: qemu: add SPL configuration doc: update QEMU RISC-V documentation
Kconfig | 4 +- Makefile | 8 +- arch/Kconfig | 6 ++ arch/riscv/Kconfig | 36 +++++++-- arch/riscv/cpu/ax25/Kconfig | 6 +- arch/riscv/cpu/cpu.c | 6 +- arch/riscv/cpu/generic/Kconfig | 5 +- arch/riscv/cpu/start.S | 62 ++++++++++++++- arch/riscv/cpu/u-boot-spl.lds | 82 +++++++++++++++++++ arch/riscv/include/asm/encoding.h | 2 +- arch/riscv/include/asm/spl.h | 31 ++++++++ arch/riscv/lib/Makefile | 8 +- arch/riscv/lib/mkimage_fit_opensbi.sh | 100 ++++++++++++++++++++++++ arch/riscv/lib/spl.c | 48 ++++++++++++ board/emulation/qemu-riscv/Kconfig | 10 +++ board/emulation/qemu-riscv/MAINTAINERS | 2 + board/emulation/qemu-riscv/qemu-riscv.c | 17 ++++ common/image.c | 1 + common/spl/Kconfig | 17 ++++ common/spl/Makefile | 1 + common/spl/spl.c | 8 +- common/spl/spl_fit.c | 37 ++++++--- common/spl/spl_opensbi.c | 85 ++++++++++++++++++++ configs/qemu-riscv32_spl_defconfig | 11 +++ configs/qemu-riscv64_spl_defconfig | 12 +++ doc/board/emulation/qemu-riscv.rst | 60 +++++++++++++- include/configs/qemu-riscv.h | 14 ++++ include/fdtdec.h | 2 +- include/image.h | 1 + include/opensbi.h | 40 ++++++++++ include/spl.h | 5 ++ lib/fdtdec.c | 6 +- 32 files changed, 691 insertions(+), 42 deletions(-) create mode 100644 arch/riscv/cpu/u-boot-spl.lds create mode 100644 arch/riscv/include/asm/spl.h create mode 100755 arch/riscv/lib/mkimage_fit_opensbi.sh create mode 100644 arch/riscv/lib/spl.c create mode 100644 common/spl/spl_opensbi.c create mode 100644 configs/qemu-riscv32_spl_defconfig create mode 100644 configs/qemu-riscv64_spl_defconfig create mode 100644 include/opensbi.h