format elf64 extrn __smp_Switch extrn __smp_PauseTicker extrn __smp_Now public __smp_IntSwitch_LastState public __smp_IntSwitch public __smp_Switch_Idle section '.bss' writable ; typedef struct { ; uint64_t rax, rbx, rcx, rdx; ; uint64_t rsi, rdi, rbp, rsp; ; uint64_t r8, r9, r10, r11; ; uint64_t r12, r13, r14, r15; ; ; uint64_t rflags; ; uint64_t rip; ; uint16_t ss, cs; // Stack and Code Segments ; } PACKED smp_thread_State; __smp_IntSwitch_LastState: rq 18 rw 2 section '.text' executable ; interrupt_handler smp_IntSwitch() ; ; Called from a timer interrupt. ; Saves the current processor (general-purpose) state and invoke the task switcher. __smp_IntSwitch: cli mov [__smp_IntSwitch_LastState], rax ; if (!__smp_PauseTicker) { ; __smp_Now++; ; if (__smp_Now % 8) ; return 0; ; } else ; __smp_PauseTicker = false; mov al, [__smp_PauseTicker] test al, al jnz .noticker mov rax, [__smp_Now] inc rax mov [__smp_Now], rax test rax, 0x7 jz .realcall mov rax, [__smp_IntSwitch_LastState] iret .noticker: mov byte [__smp_PauseTicker], 0 .realcall: mov [__smp_IntSwitch_LastState+8], rbx mov [__smp_IntSwitch_LastState+16], rcx mov [__smp_IntSwitch_LastState+24], rdx mov [__smp_IntSwitch_LastState+32], rsi ; now that we have 5 free registers, pop the iret flags for later pop rax ; rip pop rbx ; cs pop rcx ; rflags pop rdx ; rsp pop rsi ; ss mov [__smp_IntSwitch_LastState+40], rdi mov [__smp_IntSwitch_LastState+48], rbp mov [__smp_IntSwitch_LastState+56], rdx ; rsp mov [__smp_IntSwitch_LastState+64], r8 mov [__smp_IntSwitch_LastState+72], r9 mov [__smp_IntSwitch_LastState+80], r10 mov [__smp_IntSwitch_LastState+88], r11 mov [__smp_IntSwitch_LastState+96], r12 mov [__smp_IntSwitch_LastState+104], r13 mov [__smp_IntSwitch_LastState+112], r14 mov [__smp_IntSwitch_LastState+120], r15 mov [__smp_IntSwitch_LastState+128], rcx ; rflags mov [__smp_IntSwitch_LastState+136], rax ; rip mov [__smp_IntSwitch_LastState+144], si ; ss mov [__smp_IntSwitch_LastState+146], bx ; cs call __smp_Switch ;test rax, rax ;jnz .realswitch ; nonzero return value means really a context switch .realswitch: mov rdi, [__smp_IntSwitch_LastState+40] mov rbp, [__smp_IntSwitch_LastState+48] mov rdx, [__smp_IntSwitch_LastState+56] ; rsp mov r8, [__smp_IntSwitch_LastState+64] mov r9, [__smp_IntSwitch_LastState+72] mov r10, [__smp_IntSwitch_LastState+80] mov r11, [__smp_IntSwitch_LastState+88] mov r12, [__smp_IntSwitch_LastState+96] mov r13, [__smp_IntSwitch_LastState+104] mov r14, [__smp_IntSwitch_LastState+112] mov r15, [__smp_IntSwitch_LastState+120] mov rcx, [__smp_IntSwitch_LastState+128] ; rflags mov rax, [__smp_IntSwitch_LastState+136] ; rip mov si, [__smp_IntSwitch_LastState+144] ; ss mov bx, [__smp_IntSwitch_LastState+146] ; cs push rsi ; ss push rdx ; rsp push rcx ; rflags push rbx ; cs push rax ; rip mov rax, [__smp_IntSwitch_LastState] mov rbx, [__smp_IntSwitch_LastState+8] mov rcx, [__smp_IntSwitch_LastState+16] mov rdx, [__smp_IntSwitch_LastState+24] mov rsi, [__smp_IntSwitch_LastState+32] iret __smp_Switch_Idle: hlt jmp __smp_Switch_Idle jmp __smp_Switch_Idle ret