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CH32V10X 适配

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pchen
2026-05-28 15:23:19 +08:00
parent dc144a5cf4
commit e5a2334bb6
3 changed files with 379 additions and 285 deletions
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CPU/CH32V10x/os_port_gnu.S
+324 -219
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@@ -33,220 +33,286 @@ cpu_clz:
#endif
.section .text.os_port_context_switch_to,"ax",%progbits
.align 8
.align 2
.func
.global os_port_context_switch_to
.extern os_port_on_switch_success
os_port_context_switch_to:
/* machine mode, disable ISR */
li t0, 0x1800
csrw mstatus, t0
li t0, 0x1800
csrw mstatus, t0 // 1. 关中断
/* first save interrupt stack */
la t0, _eusrstack
addi t0, t0, -512
csrw mscratch,t0
/* 设置中断栈/系统栈空间 */
la t0, _eusrstack
addi t0, t0, -512
csrw mscratch, t0 // 备用栈指针存入 mscratch
/* restore sp */
LOAD sp, (a0)
/* =====================================================================
* 第一步：切换到中断栈，安全调用通知 C 函数
* ===================================================================== */
jal os_port_on_switch_success // 调用 C 函数（此时随便它怎么污染寄存器）
csrrw sp, mscratch, sp
jal os_port_on_switch_success
csrrw sp, mscratch, sp
/* =====================================================================
* 第二步：获取新任务的栈指针 SP
* ===================================================================== */
LOAD sp, 0(a0) // a0 是传入的 &g_os_port_switch_to_sp，从中取出 sp
/* restore mstatus.MPIE */
LOAD a0, 0*REG_BYTES(sp)
csrs mstatus, a0
/* restore mepc */
LOAD a0, 2 * REG_BYTES(sp)
csrw mepc, a0
/* return address */
LOAD x1, 1 * REG_BYTES(sp)
LOAD x4, 4 * REG_BYTES(sp)
LOAD x5, 5 * REG_BYTES(sp)
LOAD x6, 6 * REG_BYTES(sp)
LOAD x7, 7 * REG_BYTES(sp)
LOAD x8, 8 * REG_BYTES(sp)
LOAD x9, 9 * REG_BYTES(sp)
LOAD x10, 10 * REG_BYTES(sp)
LOAD x11, 11 * REG_BYTES(sp)
LOAD x12, 12 * REG_BYTES(sp)
LOAD x13, 13 * REG_BYTES(sp)
LOAD x14, 14 * REG_BYTES(sp)
LOAD x15, 15 * REG_BYTES(sp)
LOAD x16, 16 * REG_BYTES(sp)
LOAD x17, 17 * REG_BYTES(sp)
LOAD x18, 18 * REG_BYTES(sp)
LOAD x19, 19 * REG_BYTES(sp)
LOAD x20, 20 * REG_BYTES(sp)
LOAD x21, 21 * REG_BYTES(sp)
LOAD x22, 22 * REG_BYTES(sp)
LOAD x23, 23 * REG_BYTES(sp)
LOAD x24, 24 * REG_BYTES(sp)
LOAD x25, 25 * REG_BYTES(sp)
LOAD x26, 26 * REG_BYTES(sp)
LOAD x27, 27 * REG_BYTES(sp)
LOAD x28, 28 * REG_BYTES(sp)
LOAD x29, 29 * REG_BYTES(sp)
LOAD x30, 30 * REG_BYTES(sp)
LOAD x31, 31 * REG_BYTES(sp)
addi sp, sp, CONTEXT_SIZE
/* load float reg */
#if (OS_CFG_CPU_MPU_PRESENT)
FLOAD f0, 0 * REG_BYTES(sp)
FLOAD f1, 1 * REG_BYTES(sp)
FLOAD f2, 2 * REG_BYTES(sp)
FLOAD f3, 3 * REG_BYTES(sp)
FLOAD f4, 4 * REG_BYTES(sp)
FLOAD f5, 5 * REG_BYTES(sp)
FLOAD f6, 6 * REG_BYTES(sp)
FLOAD f7, 7 * REG_BYTES(sp)
FLOAD f8, 8 * REG_BYTES(sp)
FLOAD f9, 9 * REG_BYTES(sp)
FLOAD f10, 10 * REG_BYTES(sp)
FLOAD f11, 11 * REG_BYTES(sp)
FLOAD f12, 12 * REG_BYTES(sp)
FLOAD f13, 13 * REG_BYTES(sp)
FLOAD f14, 14 * REG_BYTES(sp)
FLOAD f15, 15 * REG_BYTES(sp)
FLOAD f16, 16 * REG_BYTES(sp)
FLOAD f17, 17 * REG_BYTES(sp)
FLOAD f18, 18 * REG_BYTES(sp)
FLOAD f19, 19 * REG_BYTES(sp)
FLOAD f20, 20 * REG_BYTES(sp)
FLOAD f21, 21 * REG_BYTES(sp)
FLOAD f22, 22 * REG_BYTES(sp)
FLOAD f23, 23 * REG_BYTES(sp)
FLOAD f24, 24 * REG_BYTES(sp)
FLOAD f25, 25 * REG_BYTES(sp)
FLOAD f26, 26 * REG_BYTES(sp)
FLOAD f27, 27 * REG_BYTES(sp)
FLOAD f28, 28 * REG_BYTES(sp)
FLOAD f29, 29 * REG_BYTES(sp)
FLOAD f30, 30 * REG_BYTES(sp)
FLOAD f31, 31 * REG_BYTES(sp)
addi sp, sp, 32 * REG_BYTES
/* =====================================================================
* 第三步：恢复 FPU 浮点寄存器（与保存栈帧严格镜像）
* 修复宏定义：将 MPU 改回 FPU
* ===================================================================== */
#if (OS_CFG_CPU_FPU_PRESENT)
FLOAD f0, (CONTEXT_SIZE + 0 * REG_BYTES)(sp)
FLOAD f1, (CONTEXT_SIZE + 1 * REG_BYTES)(sp)
FLOAD f2, (CONTEXT_SIZE + 2 * REG_BYTES)(sp)
FLOAD f3, (CONTEXT_SIZE + 3 * REG_BYTES)(sp)
FLOAD f4, (CONTEXT_SIZE + 4 * REG_BYTES)(sp)
FLOAD f5, (CONTEXT_SIZE + 5 * REG_BYTES)(sp)
FLOAD f6, (CONTEXT_SIZE + 6 * REG_BYTES)(sp)
FLOAD f7, (CONTEXT_SIZE + 7 * REG_BYTES)(sp)
FLOAD f8, (CONTEXT_SIZE + 8 * REG_BYTES)(sp)
FLOAD f9, (CONTEXT_SIZE + 9 * REG_BYTES)(sp)
FLOAD f10, (CONTEXT_SIZE + 10 * REG_BYTES)(sp)
FLOAD f11, (CONTEXT_SIZE + 11 * REG_BYTES)(sp)
FLOAD f12, (CONTEXT_SIZE + 12 * REG_BYTES)(sp)
FLOAD f13, (CONTEXT_SIZE + 13 * REG_BYTES)(sp)
FLOAD f14, (CONTEXT_SIZE + 14 * REG_BYTES)(sp)
FLOAD f15, (CONTEXT_SIZE + 15 * REG_BYTES)(sp)
FLOAD f16, (CONTEXT_SIZE + 16 * REG_BYTES)(sp)
FLOAD f17, (CONTEXT_SIZE + 17 * REG_BYTES)(sp)
FLOAD f18, (CONTEXT_SIZE + 18 * REG_BYTES)(sp)
FLOAD f19, (CONTEXT_SIZE + 19 * REG_BYTES)(sp)
FLOAD f20, (CONTEXT_SIZE + 20 * REG_BYTES)(sp)
FLOAD f21, (CONTEXT_SIZE + 21 * REG_BYTES)(sp)
FLOAD f22, (CONTEXT_SIZE + 22 * REG_BYTES)(sp)
FLOAD f23, (CONTEXT_SIZE + 23 * REG_BYTES)(sp)
FLOAD f24, (CONTEXT_SIZE + 24 * REG_BYTES)(sp)
FLOAD f25, (CONTEXT_SIZE + 25 * REG_BYTES)(sp)
FLOAD f26, (CONTEXT_SIZE + 26 * REG_BYTES)(sp)
FLOAD f27, (CONTEXT_SIZE + 27 * REG_BYTES)(sp)
FLOAD f28, (CONTEXT_SIZE + 28 * REG_BYTES)(sp)
FLOAD f29, (CONTEXT_SIZE + 29 * REG_BYTES)(sp)
FLOAD f30, (CONTEXT_SIZE + 30 * REG_BYTES)(sp)
FLOAD f31, (CONTEXT_SIZE + 31 * REG_BYTES)(sp)
#endif
/* =====================================================================
* 第四步：恢复通用寄存器（最后恢复 t0）
* ===================================================================== */
LOAD x1, 1 * REG_BYTES(sp)
LOAD x4, 4 * REG_BYTES(sp)
LOAD x6, 6 * REG_BYTES(sp)
LOAD x7, 7 * REG_BYTES(sp)
LOAD x8, 8 * REG_BYTES(sp)
LOAD x9, 9 * REG_BYTES(sp)
LOAD x10, 10 * REG_BYTES(sp)
LOAD x11, 11 * REG_BYTES(sp)
LOAD x12, 12 * REG_BYTES(sp)
LOAD x13, 13 * REG_BYTES(sp)
LOAD x14, 14 * REG_BYTES(sp)
LOAD x15, 15 * REG_BYTES(sp)
LOAD x16, 16 * REG_BYTES(sp)
LOAD x17, 17 * REG_BYTES(sp)
LOAD x18, 18 * REG_BYTES(sp)
LOAD x19, 19 * REG_BYTES(sp)
LOAD x20, 20 * REG_BYTES(sp)
LOAD x21, 21 * REG_BYTES(sp)
LOAD x22, 22 * REG_BYTES(sp)
LOAD x23, 23 * REG_BYTES(sp)
LOAD x24, 24 * REG_BYTES(sp)
LOAD x25, 25 * REG_BYTES(sp)
LOAD x26, 26 * REG_BYTES(sp)
LOAD x27, 27 * REG_BYTES(sp)
LOAD x28, 28 * REG_BYTES(sp)
LOAD x29, 29 * REG_BYTES(sp)
LOAD x30, 30 * REG_BYTES(sp)
LOAD x31, 31 * REG_BYTES(sp)
/* =====================================================================
* 第五步：恢复特权级控制 CSR 寄存器
* ===================================================================== */
LOAD t0, 2 * REG_BYTES(sp) // 恢复初始 PC 到 mepc
csrw mepc, t0
LOAD t0, 0 * REG_BYTES(sp) // 从栈中读取准备好的初始 mstatus
csrw mstatus, t0 // 修复：改用 csrw 强行覆盖
LOAD x5, 5 * REG_BYTES(sp) // 此时最后安全恢复 t0(x5)
/* =====================================================================
* 第六步：统一释放栈空间并退出
* ===================================================================== */
#if (OS_CFG_CPU_FPU_PRESENT)
addi sp, sp, (CONTEXT_SIZE + 32 * REG_BYTES)
#else
addi sp, sp, CONTEXT_SIZE
#endif
mret
.endfunc
.section .text.SW_Handler,"ax",%progbits
.align 8
.align 2
.func
.global SW_Handler
.extern g_os_port_switch_from_sp
.extern g_os_port_switch_to_sp
.extern os_isr_enter
.extern os_isr_leave
.extern os_port_on_switch_success
.extern g_t0
SW_Handler:
csrci mstatus, 0x08 // 立刻关闭全局中断 MIE = 0
/* =====================================================================
* 第一步：一揽子分配所有栈空间（防止碎片和二次偏移错误）
* ===================================================================== */
#if (OS_CFG_CPU_FPU_PRESENT)
addi sp, sp, -32 * REG_BYTES
FSTORE f0, 0 * REG_BYTES(sp)
FSTORE f1, 1 * REG_BYTES(sp)
FSTORE f2, 2 * REG_BYTES(sp)
FSTORE f3, 3 * REG_BYTES(sp)
FSTORE f4, 4 * REG_BYTES(sp)
FSTORE f5, 5 * REG_BYTES(sp)
FSTORE f6, 6 * REG_BYTES(sp)
FSTORE f7, 7 * REG_BYTES(sp)
FSTORE f8, 8 * REG_BYTES(sp)
FSTORE f9, 9 * REG_BYTES(sp)
FSTORE f10, 10 * REG_BYTES(sp)
FSTORE f11, 11 * REG_BYTES(sp)
FSTORE f12, 12 * REG_BYTES(sp)
FSTORE f13, 13 * REG_BYTES(sp)
FSTORE f14, 14 * REG_BYTES(sp)
FSTORE f15, 15 * REG_BYTES(sp)
FSTORE f16, 16 * REG_BYTES(sp)
FSTORE f17, 17 * REG_BYTES(sp)
FSTORE f18, 18 * REG_BYTES(sp)
FSTORE f19, 19 * REG_BYTES(sp)
FSTORE f20, 20 * REG_BYTES(sp)
FSTORE f21, 21 * REG_BYTES(sp)
FSTORE f22, 22 * REG_BYTES(sp)
FSTORE f23, 23 * REG_BYTES(sp)
FSTORE f24, 24 * REG_BYTES(sp)
FSTORE f25, 25 * REG_BYTES(sp)
FSTORE f26, 26 * REG_BYTES(sp)
FSTORE f27, 27 * REG_BYTES(sp)
FSTORE f28, 28 * REG_BYTES(sp)
FSTORE f29, 29 * REG_BYTES(sp)
FSTORE f30, 30 * REG_BYTES(sp)
FSTORE f31, 31 * REG_BYTES(sp)
addi sp, sp, -(CONTEXT_SIZE + 32 * REG_BYTES)
#else
addi sp, sp, -CONTEXT_SIZE
#endif
addi sp, sp, -CONTEXT_SIZE // 留出栈空间
STORE t0, 5*REG_BYTES(sp) // 保存 t0
li t0, 0x80
STORE t0, 0 * REG_BYTES(sp) // 设置 MPIE
csrr t0, mepc
STORE t0, 2*REG_BYTES(sp) // 保存正在运行任务的 pc 指针
STORE x1, 1 * REG_BYTES(sp) // return address
STORE x4, 4 * REG_BYTES(sp)
STORE x6, 6 * REG_BYTES(sp)
STORE x7, 7 * REG_BYTES(sp)
STORE x8, 8 * REG_BYTES(sp)
STORE x9, 9 * REG_BYTES(sp)
STORE x10, 10 * REG_BYTES(sp)
STORE x11, 11 * REG_BYTES(sp)
STORE x12, 12 * REG_BYTES(sp)
STORE x13, 13 * REG_BYTES(sp)
STORE x14, 14 * REG_BYTES(sp)
STORE x15, 15 * REG_BYTES(sp)
STORE x16, 16 * REG_BYTES(sp)
STORE x17, 17 * REG_BYTES(sp)
STORE x18, 18 * REG_BYTES(sp)
STORE x19, 19 * REG_BYTES(sp)
STORE x20, 20 * REG_BYTES(sp)
STORE x21, 21 * REG_BYTES(sp)
STORE x22, 22 * REG_BYTES(sp)
STORE x23, 23 * REG_BYTES(sp)
STORE x24, 24 * REG_BYTES(sp)
STORE x25, 25 * REG_BYTES(sp)
STORE x26, 26 * REG_BYTES(sp)
STORE x27, 27 * REG_BYTES(sp)
STORE x28, 28 * REG_BYTES(sp)
STORE x29, 29 * REG_BYTES(sp)
STORE x30, 30 * REG_BYTES(sp)
STORE x31, 31 * REG_BYTES(sp)
la s0, g_os_port_switch_from_sp
LOAD s1, 0(s0)
STORE sp, 0(s1) // 将 sp 存入 g_os_port_switch_from_sp
// 切换到 isr stack
csrrw sp,mscratch,sp
jal os_port_on_switch_success
csrrw sp,mscratch,sp
la s0, g_os_port_switch_to_sp
LOAD s1, 0(s0)
LOAD sp, 0(s1) // 将 sp 指向 g_os_port_switch_to_sp 栈
LOAD a0, 2 * REG_BYTES(sp) // 加载/恢复 mepc
csrw mepc, a0
LOAD x1, 1*REG_BYTES(sp)
/* =====================================================================
* 第二步：保存通用寄存器
* ===================================================================== */
STORE x5, 5 * REG_BYTES(sp) // 优先保存 t0，腾出临时寄存器
li t0, 0x1800
csrs mstatus, t0 // 确保 M 模式
csrw mstatus, t0 // M 模式
LOAD t0, 0*REG_BYTES(sp) // 加载 mstatus
csrs mstatus, t0 // 恢复 mstatus
li t0, 0x1880
STORE t0, 0 * REG_BYTES(sp) // 设置 MPIE
csrr t0, mepc
STORE t0, 2*REG_BYTES(sp) // 保存正在运行任务的 pc 指针
STORE x1, 1 * REG_BYTES(sp) // ra
STORE x4, 4 * REG_BYTES(sp) // tp
STORE x6, 6 * REG_BYTES(sp) // t1
STORE x7, 7 * REG_BYTES(sp) // t2
STORE x8, 8 * REG_BYTES(sp) // s0/fp
STORE x9, 9 * REG_BYTES(sp) // s1
STORE x10, 10 * REG_BYTES(sp) // a0
STORE x11, 11 * REG_BYTES(sp) // a1
STORE x12, 12 * REG_BYTES(sp) // a2
STORE x13, 13 * REG_BYTES(sp) // a3
STORE x14, 14 * REG_BYTES(sp) // a4
STORE x15, 15 * REG_BYTES(sp) // a5
STORE x16, 16 * REG_BYTES(sp) // a6
STORE x17, 17 * REG_BYTES(sp) // a7
STORE x18, 18 * REG_BYTES(sp) // s2
STORE x19, 19 * REG_BYTES(sp) // s3
STORE x20, 20 * REG_BYTES(sp) // s4
STORE x21, 21 * REG_BYTES(sp) // s5
STORE x22, 22 * REG_BYTES(sp) // s6
STORE x23, 23 * REG_BYTES(sp) // s7
STORE x24, 24 * REG_BYTES(sp) // s8
STORE x25, 25 * REG_BYTES(sp) // s9
STORE x26, 26 * REG_BYTES(sp) // s10
STORE x27, 27 * REG_BYTES(sp) // s11
STORE x28, 28 * REG_BYTES(sp) // t3
STORE x29, 29 * REG_BYTES(sp) // t4
STORE x30, 30 * REG_BYTES(sp) // t5
STORE x31, 31 * REG_BYTES(sp) // t6
/* =====================================================================
* 第三步：保存 FPU 浮点寄存器（使用确定的、不受干扰的高位偏移）
* ===================================================================== */
#if (OS_CFG_CPU_FPU_PRESENT)
FSTORE f0, (CONTEXT_SIZE + 0 * REG_BYTES)(sp)
FSTORE f1, (CONTEXT_SIZE + 1 * REG_BYTES)(sp)
FSTORE f2, (CONTEXT_SIZE + 2 * REG_BYTES)(sp)
FSTORE f3, (CONTEXT_SIZE + 3 * REG_BYTES)(sp)
FSTORE f4, (CONTEXT_SIZE + 4 * REG_BYTES)(sp)
FSTORE f5, (CONTEXT_SIZE + 5 * REG_BYTES)(sp)
FSTORE f6, (CONTEXT_SIZE + 6 * REG_BYTES)(sp)
FSTORE f7, (CONTEXT_SIZE + 7 * REG_BYTES)(sp)
FSTORE f8, (CONTEXT_SIZE + 8 * REG_BYTES)(sp)
FSTORE f9, (CONTEXT_SIZE + 9 * REG_BYTES)(sp)
FSTORE f10, (CONTEXT_SIZE + 10 * REG_BYTES)(sp)
FSTORE f11, (CONTEXT_SIZE + 11 * REG_BYTES)(sp)
FSTORE f12, (CONTEXT_SIZE + 12 * REG_BYTES)(sp)
FSTORE f13, (CONTEXT_SIZE + 13 * REG_BYTES)(sp)
FSTORE f14, (CONTEXT_SIZE + 14 * REG_BYTES)(sp)
FSTORE f15, (CONTEXT_SIZE + 15 * REG_BYTES)(sp)
FSTORE f16, (CONTEXT_SIZE + 16 * REG_BYTES)(sp)
FSTORE f17, (CONTEXT_SIZE + 17 * REG_BYTES)(sp)
FSTORE f18, (CONTEXT_SIZE + 18 * REG_BYTES)(sp)
FSTORE f19, (CONTEXT_SIZE + 19 * REG_BYTES)(sp)
FSTORE f20, (CONTEXT_SIZE + 20 * REG_BYTES)(sp)
FSTORE f21, (CONTEXT_SIZE + 21 * REG_BYTES)(sp)
FSTORE f22, (CONTEXT_SIZE + 22 * REG_BYTES)(sp)
FSTORE f23, (CONTEXT_SIZE + 23 * REG_BYTES)(sp)
FSTORE f24, (CONTEXT_SIZE + 24 * REG_BYTES)(sp)
FSTORE f25, (CONTEXT_SIZE + 25 * REG_BYTES)(sp)
FSTORE f26, (CONTEXT_SIZE + 26 * REG_BYTES)(sp)
FSTORE f27, (CONTEXT_SIZE + 27 * REG_BYTES)(sp)
FSTORE f28, (CONTEXT_SIZE + 28 * REG_BYTES)(sp)
FSTORE f29, (CONTEXT_SIZE + 29 * REG_BYTES)(sp)
FSTORE f30, (CONTEXT_SIZE + 30 * REG_BYTES)(sp)
FSTORE f31, (CONTEXT_SIZE + 31 * REG_BYTES)(sp)
#endif
/* =====================================================================
* 第四步：保存旧任务 sp，并安全调用通知函数
* ===================================================================== */
la t0, g_os_port_switch_from_sp
LOAD t0, 0(t0)
STORE sp, 0(t0) // 将 sp 存入 g_os_port_switch_from_sp
// 此时调用 C 函数是完全安全的，因为所有寄存器都已在任务栈里备考
jal os_port_on_switch_success
/* =====================================================================
* 第五步：载入新任务的栈指针（SP）
* ===================================================================== */
la t0, g_os_port_switch_to_sp
LOAD t0, 0(t0)
LOAD sp, 0(t0) // 将 sp 指向 g_os_port_switch_to_sp 栈
/* =====================================================================
* 第六步：恢复新任务的 FPU 浮点寄存器
* ===================================================================== */
#if (OS_CFG_CPU_FPU_PRESENT)
FLOAD f0, (CONTEXT_SIZE + 0 * REG_BYTES)(sp)
FLOAD f1, (CONTEXT_SIZE + 1 * REG_BYTES)(sp)
FLOAD f2, (CONTEXT_SIZE + 2 * REG_BYTES)(sp)
FLOAD f3, (CONTEXT_SIZE + 3 * REG_BYTES)(sp)
FLOAD f4, (CONTEXT_SIZE + 4 * REG_BYTES)(sp)
FLOAD f5, (CONTEXT_SIZE + 5 * REG_BYTES)(sp)
FLOAD f6, (CONTEXT_SIZE + 6 * REG_BYTES)(sp)
FLOAD f7, (CONTEXT_SIZE + 7 * REG_BYTES)(sp)
FLOAD f8, (CONTEXT_SIZE + 8 * REG_BYTES)(sp)
FLOAD f9, (CONTEXT_SIZE + 9 * REG_BYTES)(sp)
FLOAD f10, (CONTEXT_SIZE + 10 * REG_BYTES)(sp)
FLOAD f11, (CONTEXT_SIZE + 11 * REG_BYTES)(sp)
FLOAD f12, (CONTEXT_SIZE + 12 * REG_BYTES)(sp)
FLOAD f13, (CONTEXT_SIZE + 13 * REG_BYTES)(sp)
FLOAD f14, (CONTEXT_SIZE + 14 * REG_BYTES)(sp)
FLOAD f15, (CONTEXT_SIZE + 15 * REG_BYTES)(sp)
FLOAD f16, (CONTEXT_SIZE + 16 * REG_BYTES)(sp)
FLOAD f17, (CONTEXT_SIZE + 17 * REG_BYTES)(sp)
FLOAD f18, (CONTEXT_SIZE + 18 * REG_BYTES)(sp)
FLOAD f19, (CONTEXT_SIZE + 19 * REG_BYTES)(sp)
FLOAD f20, (CONTEXT_SIZE + 20 * REG_BYTES)(sp)
FLOAD f21, (CONTEXT_SIZE + 21 * REG_BYTES)(sp)
FLOAD f22, (CONTEXT_SIZE + 22 * REG_BYTES)(sp)
FLOAD f23, (CONTEXT_SIZE + 23 * REG_BYTES)(sp)
FLOAD f24, (CONTEXT_SIZE + 24 * REG_BYTES)(sp)
FLOAD f25, (CONTEXT_SIZE + 25 * REG_BYTES)(sp)
FLOAD f26, (CONTEXT_SIZE + 26 * REG_BYTES)(sp)
FLOAD f27, (CONTEXT_SIZE + 27 * REG_BYTES)(sp)
FLOAD f28, (CONTEXT_SIZE + 28 * REG_BYTES)(sp)
FLOAD f29, (CONTEXT_SIZE + 29 * REG_BYTES)(sp)
FLOAD f30, (CONTEXT_SIZE + 30 * REG_BYTES)(sp)
FLOAD f31, (CONTEXT_SIZE + 31 * REG_BYTES)(sp)
#endif
/* =====================================================================
* 第七步：全面恢复通用寄存器（最后恢复 t0）
* ===================================================================== */
LOAD x1, 1 * REG_BYTES(sp)
LOAD x4, 4 * REG_BYTES(sp)
LOAD x5, 5 * REG_BYTES(sp)
// LOAD x5, 5 * REG_BYTES(sp) // 恢复 t0
LOAD x6, 6 * REG_BYTES(sp)
LOAD x7, 7 * REG_BYTES(sp)
LOAD x8, 8 * REG_BYTES(sp)
@@ -273,49 +339,88 @@ SW_Handler:
LOAD x29, 29 * REG_BYTES(sp)
LOAD x30, 30 * REG_BYTES(sp)
LOAD x31, 31 * REG_BYTES(sp)
addi sp, sp, CONTEXT_SIZE // 恢复栈指针
/* load float reg */
/* =====================================================================
* 第八步：恢复新任务的 CSR 寄存器
* ===================================================================== */
LOAD t0, 2 * REG_BYTES(sp) // 恢复 mepc
csrw mepc, t0
LOAD t0, 0 * REG_BYTES(sp) // 恢复 mstatus
csrw mstatus, t0
LOAD x5, 5 * REG_BYTES(sp) // 恢复 t0
/* =====================================================================
* 第九步：彻底释放栈空间并退出
* ===================================================================== */
#if (OS_CFG_CPU_FPU_PRESENT)
FLOAD f0, 0 * REG_BYTES(sp)
FLOAD f1, 1 * REG_BYTES(sp)
FLOAD f2, 2 * REG_BYTES(sp)
FLOAD f3, 3 * REG_BYTES(sp)
FLOAD f4, 4 * REG_BYTES(sp)
FLOAD f5, 5 * REG_BYTES(sp)
FLOAD f6, 6 * REG_BYTES(sp)
FLOAD f7, 7 * REG_BYTES(sp)
FLOAD f8, 8 * REG_BYTES(sp)
FLOAD f9, 9 * REG_BYTES(sp)
FLOAD f10, 10 * REG_BYTES(sp)
FLOAD f11, 11 * REG_BYTES(sp)
FLOAD f12, 12 * REG_BYTES(sp)
FLOAD f13, 13 * REG_BYTES(sp)
FLOAD f14, 14 * REG_BYTES(sp)
FLOAD f15, 15 * REG_BYTES(sp)
FLOAD f16, 16 * REG_BYTES(sp)
FLOAD f17, 17 * REG_BYTES(sp)
FLOAD f18, 18 * REG_BYTES(sp)
FLOAD f19, 19 * REG_BYTES(sp)
FLOAD f20, 20 * REG_BYTES(sp)
FLOAD f21, 21 * REG_BYTES(sp)
FLOAD f22, 22 * REG_BYTES(sp)
FLOAD f23, 23 * REG_BYTES(sp)
FLOAD f24, 24 * REG_BYTES(sp)
FLOAD f25, 25 * REG_BYTES(sp)
FLOAD f26, 26 * REG_BYTES(sp)
FLOAD f27, 27 * REG_BYTES(sp)
FLOAD f28, 28 * REG_BYTES(sp)
FLOAD f29, 29 * REG_BYTES(sp)
FLOAD f30, 30 * REG_BYTES(sp)
FLOAD f31, 31 * REG_BYTES(sp)
addi sp, sp, 32 * REG_BYTES
addi sp, sp, (CONTEXT_SIZE + 32 * REG_BYTES)
#else
addi sp, sp, CONTEXT_SIZE
#endif
/* 执行 mret。此时：
* 1. 硬件会自动把当前 mstatus.MPIE (1) 复制到 mstatus.MIE，从而开启全局中断。
* 2. 程序跳转到 mepc 寄存器指向的地址（即新任务继续运行的代码处）。 */
mret // 从 M 模式退出
.endfunc
.section .text.SysTick_Handler,"ax",%progbits
.align 2
.global SysTick_Handler
.extern SysTick_Handler_C
.func
SysTick_Handler:
// csrci mstatus, 8 // 关闭中断
/* 1. 因为是硬件中断，先在当前栈上保存必要的临时寄存器(Caller-saved) */
addi sp, sp, -16 * REG_BYTES
STORE x1, 0 * REG_BYTES(sp) # ra
STORE x5, 1 * REG_BYTES(sp) # t0
STORE x6, 2 * REG_BYTES(sp) # t1
STORE x7, 3 * REG_BYTES(sp) # t2
STORE x10, 4 * REG_BYTES(sp) # a0
STORE x11, 5 * REG_BYTES(sp) # a1
STORE x12, 6 * REG_BYTES(sp) # a2
STORE x13, 7 * REG_BYTES(sp) # a3
STORE x14, 8 * REG_BYTES(sp) # a4
STORE x15, 9 * REG_BYTES(sp) # a5
STORE x16, 10 * REG_BYTES(sp) # a6
STORE x17, 11 * REG_BYTES(sp) # a7
STORE x28, 12 * REG_BYTES(sp) # t3
STORE x29, 13 * REG_BYTES(sp) # t4
STORE x30, 14 * REG_BYTES(sp) # t5
STORE x31, 15 * REG_BYTES(sp) # t6
/* 2. 清除定时器硬件中断标志位（防止重复触发），并调用 C 语言的时钟处理函数 */
jal SysTick_Handler_C
/* 3. 恢复临时寄存器 */
LOAD x1, 0 * REG_BYTES(sp) # ra
LOAD x5, 1 * REG_BYTES(sp) # t0
LOAD x6, 2 * REG_BYTES(sp) # t1
LOAD x7, 3 * REG_BYTES(sp) # t2
LOAD x10, 4 * REG_BYTES(sp) # a0
LOAD x11, 5 * REG_BYTES(sp) # a1
LOAD x12, 6 * REG_BYTES(sp) # a2
LOAD x13, 7 * REG_BYTES(sp) # a3
LOAD x14, 8 * REG_BYTES(sp) # a4
LOAD x15, 9 * REG_BYTES(sp) # a5
LOAD x16, 10 * REG_BYTES(sp) # a6
LOAD x17, 11 * REG_BYTES(sp) # a7
LOAD x28, 12 * REG_BYTES(sp) # t3
LOAD x29, 13 * REG_BYTES(sp) # t4
LOAD x30, 14 * REG_BYTES(sp) # t5
LOAD x31, 15 * REG_BYTES(sp) # t6
addi sp, sp, 16 * REG_BYTES
/* 4. 退出硬件中断 */
mret
.endfunc
.align 4
.end