[feat] Simple Multitask

2026-05-31 12:11:57 +08:00
parent 45693c96b5
commit b8212e2127
5 changed files with 307 additions and 3 deletions
@@ -0,0 +1,30 @@
+.intel_syntax noprefix
+
+// void context_switch(UINT64* old_rsp, UINT64 new_rsp)
+// rdi = &old_rsp  (pointer to save current RSP)
+// rsi = new_rsp   (value of new stack pointer)
+//
+// Saves/restores callee-saved registers only.
+// On first switch into a new task, ret lands on task_entry_trampoline.
+.global context_switch
+context_switch:
+    push rbx
+    push rbp
+    push r12
+    push r13
+    push r14
+    push r15
+
+    mov [rdi], rsp      // save current RSP
+    mov rsp, rsi        // switch to new stack
+
+    pop r15
+    pop r14
+    pop r13
+    pop r12
+    pop rbp
+    pop rbx
+
+    ret
+
+.section .note.GNU-stack,"",@progbits