Files
rt-thread/libcpu/risc-v/common64
Tm-C-mT acef64ed2a [libcpu-riscv]: [surpport SMP]: Add SMP support for qemu-virt64-riscv
1.Add the necessary function declarations for SMP enablement and implement the corresponding
functionalities, including rt_hw_secondary_cpu_up, secondary_cpu_entry, rt_hw_local_irq_disable,
rt_hw_local_irq_enable, rt_hw_secondary_cpu_idle_exec, rt_hw_spin_lock_init, rt_hw_spin_lock,
rt_hw_spin_unlock, rt_hw_ipi_send, rt_hw_interrupt_set_priority, rt_hw_interrupt_get_priority,
rt_hw_ipi_init, rt_hw_ipi_handler_install, and rt_hw_ipi_handler.

2.In the two functions (rt_hw_context_switch_to and rt_hw_context_switch) in context_gcc.S,
add a call to rt_cpus_lock_status_restore to update the scheduler information.

3.If the MMU is enabled, use the .percpu section and record different hartids by configuring
special page tables; if the MMU is not enabled, record them directly in the satp register.
Additionally, add dynamic startup based on core configuration.The .percpu section is only used
when both ARCH_MM_MMU and RT_USING_SMP are enabled. However, there is a certain amount of space
waste since no macro guard is added for it in the link script currently.

4.The physical memory of QEMU started in CI is 128MB, so RT_HW_PAGE_END is modified from the
original +256MB to +128MB. Modify the SConscript file under the common64 directory to include
common/atomic_riscv.c in the compilation process.

Signed-off-by: Mengchen Teng <teng_mengchen@163.com>
2025-12-04 15:42:09 +08:00
..

RT-Thread RV64支持

1.概述

该目录提供RT-Thread标准版及SMART版本对rv64体系结构支持其中包括

文件名 文件内容 参考标准
atomic_rv64.c 原子操作实现接口 "A" Extension for Atomic Instructions, Version 2.1
context_gcc.S 线程上下文切换 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
cpuport_gcc.S 线程统一入口
cpuport.c 线程栈初始化
cpuport.h 通用寄存器、浮点、向量寄存器个数定义,内存屏障接口 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
interrupt_gcc.S 异常/中断处理、全局中断使能/关闭 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
io.h 以字节、字、双字读、写IO地址接口
encoding.h CSR寄存器定义 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
vector_encoding.h vector相关指令定义 RISC-V "V" Standard Extension for Vector Operations, Version 1.0
ext_context.h 浮点/向量上下文保存与恢复 RISC-V "V" Standard Extension for Vector Operations, Version 1.0 "F" Extension for Single-Precision Floating-Point Version 2.2
mmu.c rv64 sv39 mmu管理接口 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
mmu.h rv64 sv39 mmu页表相关定义 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
asid.c rv64 mmu asid支持 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
riscv_mmu.c 使能/关闭S态访问用户态页表 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
sbi.c 通过ecall调用SBI相关信息接口 RISC-V Supervisor Binary Interface Specification Version 1.0
sbi.h SBI spec相关接口定义 RISC-V Supervisor Binary Interface Specification Version 1.0
stack.h 线程栈数据定义 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
stackframe.h 线程上下文保存/恢复 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
syscall_c.c 系统调用处理
tick.c S态时钟初始化及中断处理
tlb.h tlb刷新/无效接口 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12
trap.c 异常/中断处理,包括中断分发及用户态异常处理 The RISC-V Instruction Set Manual Volume II: privileged supervisor-level ISA version 1.12

2.运行模式配置

选项 默认值 说明
RISCV_VIRT64_S_MODE 打开 系统启动后是否运行在S态关闭时系统将运行在M态目前系统存在bug尚不可直接运行在M态故此开关必须打开
RT_USING_SMART 关闭 是否开启RTThread SMART版本开启后系统运行在S+U态且会开启MMU页表(satp);关闭时系统仅运行在S态MMU关闭(satp为bare translation)
ARCH_USING_ASID 关闭 MMU是否支持asid

3.移植指南

1增加新的CPU支持

创建libcpu/risc-v/<VENDOR_NAME>/<CPU_NAME>新目录,同时在libcpu/risc-v/SConscript中增加该CPU。

2PLIC中断控制器支持

libcpu/risc-v/virt64/plic.[c|h]提供了符合《RISC-V Platform-Level Interrupt Controller Specification version 1.0.0 》标准的PLIC中断控制器驱动代码可作为移植参考。

3串口uart支持

目前串口驱动在各bsp目录下可参考bsp/qemu-virt64-riscv/driver/drv_uart.[c|h]