[U-Boot] [PATCH v3 00/11] SPL support for RISC-V

[Lukas Auer]

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 v3:
- Rebase on u-boot-riscv/master
- Update commit message to include minimum version of OpenSBI
- Rebase on u-boot/master
- Add note on minimum version of OpenSBI

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

-- 
2.21.0