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Diffstat (limited to 'na/arch/riscv/trap/swtch.S')
| -rw-r--r-- | na/arch/riscv/trap/swtch.S | 96 |
1 files changed, 0 insertions, 96 deletions
diff --git a/na/arch/riscv/trap/swtch.S b/na/arch/riscv/trap/swtch.S deleted file mode 100644 index dbae43d..0000000 --- a/na/arch/riscv/trap/swtch.S +++ /dev/null @@ -1,96 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* Copyright (C) 2026 Richard Qin */ - -/* - * Context Switch & Kernel Thread Trampoline (RISC-V 64) - * - * context_switch: saves/restores callee-saved registers. - * kthread_entry_trampoline: entry point for newly created kernel threads. - * After context_switch loads the new Context, execution lands here via - * Context.ra = kthread_entry_trampoline. The entry function and argument - * are in s0 and s1 respectively, set by sched_init/create_tcb. - * - * The trampoline calls the MI-layer kthread_entry(entry, arg). - * - * Reference: docs/specs/scheduler.md ยง6 - */ - - .section .text - -/* ======================================================================== - * void context_switch(Context* old_ctx, Context* next_ctx); - * a0 = old_ctx_ptr, a1 = next_ctx_ptr - * ======================================================================== */ - .globl context_switch - .align 2 -context_switch: - sd ra, 0(a0) - sd sp, 8(a0) - sd s0, 16(a0) - sd s1, 24(a0) - sd s2, 32(a0) - sd s3, 40(a0) - sd s4, 48(a0) - sd s5, 56(a0) - sd s6, 64(a0) - sd s7, 72(a0) - sd s8, 80(a0) - sd s9, 88(a0) - sd s10, 96(a0) - sd s11, 104(a0) - - ld ra, 0(a1) - ld sp, 8(a1) - ld s0, 16(a1) - ld s1, 24(a1) - ld s2, 32(a1) - ld s3, 40(a1) - ld s4, 48(a1) - ld s5, 56(a1) - ld s6, 64(a1) - ld s7, 72(a1) - ld s8, 80(a1) - ld s9, 88(a1) - ld s10, 96(a1) - ld s11, 104(a1) - - ret - -/* ======================================================================== - * kthread_entry_trampoline - * - * Reached via context_switch when a new kthread is first scheduled. - * Context was set up by create_tcb(): - * s0 = entry function pointer - * s1 = argument pointer - * - * Calls the MI-layer C++ function: - * void kthread_entry(void (*entry)(void*), void* arg); - * ======================================================================== */ - .globl kthread_entry_trampoline - .align 2 -kthread_entry_trampoline: - mv a0, s0 /* a0 = entry function */ - mv a1, s1 /* a1 = argument */ - call kthread_entry /* MI-layer C++ function */ - - /* kthread_entry should never return, but if it does: */ - wfi - j kthread_entry_trampoline + 12 /* loop on wfi */ - -/* ======================================================================== - * ret_from_fork - * - * Trampoline for newly forked processes. - * Context is set up by fork() so that s0 contains the TrapFrame pointer. - * - * Calls the MI-layer C++ function: - * void fork_child_entry(TrapFrame* tf); - * ======================================================================== */ - .globl ret_from_fork - .align 2 -ret_from_fork: - mv a0, s0 /* a0 = TrapFrame pointer */ - call fork_child_entry /* does not return, eventually calls userret */ - wfi - j ret_from_fork + 8
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