Hi Sean,
Will address your comment in v2 by moving the ARM and RISCV code to generic lib/semihosting.c.
On Thu, Sep 15, 2022 at 8:55 PM Sean Anderson sean.anderson@seco.com wrote:
Hi Kautuk,
On 9/15/22 8:45 AM, Kautuk Consul wrote:
[You don't often get email from kconsul@ventanamicro.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
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.
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 (2): arch/riscv: add semihosting support for RISC-V board: qemu-riscv: enable semihosting
arch/riscv/Kconfig | 45 ++++++++ arch/riscv/include/asm/semihosting.h | 11 ++ arch/riscv/include/asm/spl.h | 1 + arch/riscv/lib/Makefile | 7 ++ arch/riscv/lib/semihosting.c | 166 +++++++++++++++++++++++++++ arch/riscv/lib/semihosting_mmode.c | 77 +++++++++++++ arch/riscv/lib/semihosting_smode.c | 77 +++++++++++++
I don't think this is the right approach. The semihosting ABI is effectively identical on Arm and RISC-V, with the exception of the actual trap instruction. I think we should add support for RISC-V by moving the semihosting code (and Kconfig options) to e.g. lib/, and reduce the arch-specific code to just smh_trap (and any exception handlers).
Does that seem reasonable to you?
--Sean
configs/qemu-riscv32_defconfig | 4 + configs/qemu-riscv32_smode_defconfig | 4 + configs/qemu-riscv32_spl_defconfig | 5 + configs/qemu-riscv64_defconfig | 4 + configs/qemu-riscv64_smode_defconfig | 4 + configs/qemu-riscv64_spl_defconfig | 5 + include/configs/qemu-riscv.h | 2 + 14 files changed, 412 insertions(+) create mode 100644 arch/riscv/include/asm/semihosting.h create mode 100644 arch/riscv/lib/semihosting.c create mode 100644 arch/riscv/lib/semihosting_mmode.c create mode 100644 arch/riscv/lib/semihosting_smode.c
-- 2.34.1