Semihosting is a mechanism that enables code running on a target to communicate and use the Input/Output facilities on a host computer that is running a debugger. This patchset adds support for semihosting in u-boot for RISCV64 targets.
CHANGES since v1: - Moved the identical smh_* and semihosting_enabled/disable_semihosting code of ARM and RISC-V to lib/semihosting.c - Extend the handle_trap() functionality to call disable_semihosting() if the cause is a breakpoint (i.e. ebreak instruction) - Change our implementation of semihosting_enabled to be exactly the same as the way ARM implemented it - Additionally enable the CONFIG_SPL_FS_EXT4 and CONFIG_SPL_FS_FAT configs for qemu defconfigs so that CONFIG_SPL_FS_LOAD_PAYLOAD_NAME gets automatically enabled instead of us #defining it in include/configs/qemu-riscv.h
Compilation and test commands for SPL and S-mode configurations =================================================================
U-Boot S-mode on QEMU virt ---------------------------- // Compilation of S-mode u-boot ARCH=riscv CROSS_COMPILE=riscv64-unknown-linux-gnu- make qemu-riscv64_smode_defconfig make // Run riscv 64-bit u-boot with opensbi on qemu qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\ opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\ u-boot/u-boot.bin
U-Boot SPL on QEMU virt ------------------------ // Compilation of u-boot-spl ARCH=riscv CROSS_COMPILE=riscv64-unknown-linux-gnu- make qemu-riscv64_spl_defconfig make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin // Run 64-bit u-boot-spl in qemu qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\ u-boot/spl/u-boot-spl.bin -device\ loader,file=u-boot/u-boot.itb,addr=0x80200000
Kautuk Consul (3): lib: Add common semihosting library arch/riscv: add semihosting support for RISC-V board: qemu-riscv: enable semihosting
arch/arm/Kconfig | 2 + arch/arm/lib/semihosting.c | 179 +------------------------- arch/riscv/Kconfig | 47 +++++++ arch/riscv/include/asm/semihosting.h | 11 ++ arch/riscv/include/asm/spl.h | 1 + arch/riscv/lib/Makefile | 2 + arch/riscv/lib/interrupts.c | 11 ++ arch/riscv/lib/semihosting.c | 24 ++++ configs/qemu-riscv32_defconfig | 4 + configs/qemu-riscv32_smode_defconfig | 4 + configs/qemu-riscv32_spl_defconfig | 7 + configs/qemu-riscv64_defconfig | 4 + configs/qemu-riscv64_smode_defconfig | 4 + configs/qemu-riscv64_spl_defconfig | 7 + include/semihosting.h | 11 ++ lib/Kconfig | 3 + lib/Makefile | 2 + lib/semihosting.c | 186 +++++++++++++++++++++++++++ 18 files changed, 331 insertions(+), 178 deletions(-) create mode 100644 arch/riscv/include/asm/semihosting.h create mode 100644 arch/riscv/lib/semihosting.c create mode 100644 lib/semihosting.c