Implemented lazy FPU, GP relaxation, and QEMU automation for GNU port in arch/risc-v32 (#513)

2026-05-25T20:43:24Z

This PR adds three functional improvements to the RISC-V 32-bit GNU port. Lazy FPU stacking (tx_thread_context_save.S, tx_thread_context_restore.S, tx_thread_schedule.S): FP register save/restore is now skipped whenmstatus.FS is Off, reducing context switch overhead for threads that do not use floating point. GP relaxation (cmake/riscv32_gnu.cmake, entry.s, link.lds): Enables the -mrelax compiler flag and defines __global_pointer$ in the linker script.The entry stub initializes gp at startup. gp is not saved or restored during context switches. WFI in idle loop (tx_thread_schedule.S): The scheduler issues wfi when no thread is ready, replacing busy-waiting with a low-power sleep. A Python/QEMU/GDB functional test runner is added under ports/risc-v32/gnu/example_build/qemu_virt/test/. It validates context switching, FPUcontext preservation, timer interrupts, and preemption. To run: cd ports/risc-v32/gnu/example_build/qemu_virt make check-functional-riscv32 Tested on QEMU virt machine (rv32gc). Co-authored-by: Wei-Chen Lai Winstonllllai@users.noreply.github.com Co-authored-by: Frédéric Desbiens frederic.desbiens@eclipse-foundation.org Co-authored-by: Copilot 223556219+Copilot@users.noreply.github.com

Add RISC-V32 QEMU-virt example

2026-01-01T09:22:29Z

This commit introduces the complete example build environment for the RISC-V32/GNU port targeting the QEMU virt machine. It includes basic BSP components, startup code, drivers, linker script, and a minimal ThreadX demo application. Signed-off-by: Akif Ejaz

threadx.git/ports/risc-v32/gnu/example_build/qemu_virt/link.lds, branch dev

Implemented lazy FPU, GP relaxation, and QEMU automation for GNU port in arch/risc-v32 (#513)

Add RISC-V32 QEMU-virt example