kernel threads

kernel threads and preemptive multitasking

src/arch/x86_64/Makefile

@@ -1,4 +1,4 @@
-objects := $(patsubst %.c,%.o,$(wildcard *.c)) israsm.o
+objects := $(patsubst %.c,%.o,$(wildcard *.c)) israsm.o context.o
 subdirs=boot
 OBJPATH=$(OBJDIR)/arch/${TARGET}/
 export
@@ -15,3 +15,7 @@ israsm.o: isr.asm
 	nasm -f elf64 -o $@ $<
 	mkdir -p $(OBJPATH)
 	cp $@ $(OBJPATH)/$@
+context.o: context.asm
+	nasm -f elf64 -o $@ $<
+	mkdir -p $(OBJPATH)
+	cp $@ $(OBJPATH)/$@

src/arch/x86_64/context.asm

@@ -0,0 +1,32 @@
+global arch_switchcontext
+arch_switchcontext:
+	mov rsp,rdi
+	add rsp, 8 ; cr2
+        pop rax
+        mov gs,rax
+        pop rax
+        mov fs,rax
+        pop rax
+        mov es,rax
+        pop rax
+        mov ds,rax
+        pop rax
+        pop rbx
+        pop rcx
+        pop rdx
+        pop r8
+        pop r9
+        pop r10
+        pop r11
+        pop r12
+        pop r13
+        pop r14
+        pop r15
+        pop rdi
+        pop rsi
+        pop rbp
+        add rsp,8 ; remove error code
+	
+	swapgs
+	
+	iretq

src/arch/x86_64/include/arch/cls.h

@@ -22,6 +22,7 @@ typedef struct{
 	thread_t* thread;
 	size_t timerticksperus;
 	timer_req* timerfirstreq;
+	timer_req  schedreq;
 } cls_t;
 
 void bsp_setcls();

src/arch/x86_64/include/arch/kstack.h

@@ -0,0 +1,6 @@
+#ifndef _KSTACK_H_INCLUDE
+#define _KSTACK_H_INCLUDE
+
+void arch_setkernelstack(void*);
+
+#endif

src/arch/x86_64/include/arch/regs.h

@@ -2,10 +2,12 @@
 #define _REGS_H_INCLUDE
 
 #include <stdint.h>
+#include <stdbool.h>
 
 typedef struct{
         uint64_t cr2,gs,fs,es,ds,rax,rbx,rcx,rdx,r8,r9,r10,r11,r12,r13,r14,r15,rdi,rsi,rbp,error,rip,cs,rflags,rsp,ss;
 } arch_regs;
 
+void arch_regs_setupkernel(arch_regs* regs, void* ip, void* stack, bool interrupts);
 
 #endif

src/arch/x86_64/isr.asm

@@ -75,7 +75,7 @@ section .text
 	pop rdi
 	pop rsi
 	pop rbp
-
+	add rsp,8 ; remove error code
 
 %endmacro
 
@@ -95,8 +95,6 @@ section .text
 	call %2
 	
 	popregs
-	
-	add rsp,8 ; remove error code
 
 	iretq
 	
@@ -120,9 +118,7 @@ section .text
 	call %2
 	
 	popregs
-
-	add rsp,8 ; remove error code
-
+	
 	iretq
 %endmacro
 

src/arch/x86_64/kstack.c

@@ -0,0 +1,8 @@
+#include <arch/kstack.h>
+#include <arch/ist.h>
+#include <arch/cls.h>
+
+void arch_setkernelstack(void* stack){
+	
+	arch_getcls()->ist.rsp0 = (uint64_t)stack;
+}

src/arch/x86_64/main.c

@@ -28,9 +28,7 @@ struct limine_terminal_response* liminetty;
 int  ttylock = 0;
 
 void liminewrite(char* str, size_t c){
-
 	liminetty->write(liminetty->terminals[0], str, c);
-
 }
 
 void kmain(){
@@ -80,6 +78,8 @@ void kmain(){
 
 	pci_enumerate();
 
+	sched_init();
+
 	smp_init();
 
 	_panic("End of kmain()", 0);

src/arch/x86_64/regs.c

@@ -0,0 +1,13 @@
+#include <arch/regs.h>
+
+void arch_regs_setupkernel(arch_regs* regs, void* ip, void* stack, bool interrupts){
+        regs->rip = ip;
+        regs->rsp = stack;
+        regs->cs = 0x28;
+        regs->ds = 0x30;
+        regs->es = 0x30;
+        regs->fs = 0x30;
+        regs->gs = 0x30;
+        regs->ss = 0x30;
+        regs->rflags = interrupts ? 0x200 : 0;	
+}