wip on fork

minimal example works

kernel/main.cc

@@ -100,9 +100,9 @@ extern "C" int main() {
 
     }
     
-    Thread* thread_ptr = new Thread(false, (void*)0x4000000, (void*)0x4001000, 2);
+    //Thread* thread_ptr = new Thread(false, (void*)0x4000000, (void*)0x4001000, 2);
-    g.vault().scheduler.ready(thread_ptr);
+    //g.vault().scheduler.ready(thread_ptr);
-    g.vault().thread_list[thread_ptr->id] = thread_ptr;
+    //g.vault().thread_list[thread_ptr->id] = thread_ptr;
 
     //for(void* p=Multiboot::getModule(0)->getStartAddress(); p<Multiboot::getModule(0)->getEndAddress(); p=(void*)((uintptr_t)p+4096)){
     //    DBG << "module at: " << hex << p << endl;

kernel/memory/pagetable.cc

@@ -231,6 +231,8 @@ void copy_pagetable(four_lvl_paging_t* parent_table, four_lvl_paging_t* child_ta
                                 ((uintptr_t)i3<<30) |
                                 ((uintptr_t)i2<<21) |
                                 ((uintptr_t)i1<<12) ;
+                            if(vaddr < 0x4000000)
+                                continue;
                             if(!isMapped(vaddr, child_table)){
                                 //only copy if not part of basic pagetable
                                 assert( (i3>0) || (i2>=32)); //assert user memory 

kernel/syscall/skeleton.cc

@@ -9,6 +9,7 @@
 #include "../thread/scheduler.h"
 #include "../memory/pageframealloc.h"
 #include "../memory/pagetable.h"
+#include "../arch/idt.h"
 void *operator new(size_t, void *);
 
 //#include "../user/app1/appl.h"
@@ -175,8 +176,6 @@ namespace Syscall {
 
 
 bool copy_from_phys(Vault& vault, uintptr_t phys_ptr, void* virt_ptr, size_t size) {
-	Thread* current_thread = vault.scheduler.active();
-	
 	size_t offset = Page::offset(phys_ptr); 
 	size_t total_size = size + offset;
     four_lvl_paging_t* search_table = vault.scheduler.active()->paging_tree;
@@ -280,9 +279,25 @@ bool reply(Vault& v, const void* buffer, size_t size) {
   return true;
 }
 
+void copy_stack(Thread* parent, Thread* child){
+    uintptr_t dest_frame = isMapped((uintptr_t)child->StackPointer.user, child->paging_tree);
+    void* dest_vaddr = getFreeVirtSpace(parent->paging_tree, 1);
+    setMapping((uintptr_t)dest_vaddr, (void*)dest_frame, parent->paging_tree);
+
+    memcpy(dest_vaddr, (void*)0x6000000/*((uintptr_t)parent->StackPointer.user & ~0xFFF)*/, 4096);
+
+    setMapping((uintptr_t)dest_vaddr, 0, parent->paging_tree);
+}
+
 int fork(Vault &vault, InterruptContext *user_context) {
     Thread* parent = vault.scheduler.active();
-    //Thread* child = new Thread(false, 
+    Thread* child = new Thread(false, (void*)user_context->ip, parent->code_paddr, parent->code_pagenum);
+    copy_pagetable(parent->paging_tree, child->paging_tree);
+    copy_stack(parent, child);
+
+    child->StackPointer.user = (void*)user_context->sp;
+
+    vault.scheduler.ready(child);
     
     return 0;
 }

kernel/syscall/stub.asm

@@ -6,7 +6,21 @@
 align 8
 sys_call:
 	; BSB2 1 - Syscall stub
+    push rbx
+    push rbp
+    push r11
+    push r12
+    push r13
+    push r14
+    push r15
     int 0x80
+    pop r15
+    pop r14
+    pop r13
+    pop r12
+    pop r11
+    pop rbp
+    pop rbx
     ret
 
 

kernel/thread/thread.cc

@@ -4,6 +4,7 @@
 #include "../arch/core_ring.h"
 #include "../memory/pageframealloc.h"
 #include "../memory/pagetable.h"
+#include "../memory/page.h"
 #include "../debug/kernelpanic.h"
 #include "../interrupt/guard.h"
 #include "debug/output.h"
@@ -49,11 +50,11 @@ void Thread::map_app(void* code_paddr, uint16_t code_page_num, void* stack_vaddr
 	}
 }
 
-Thread::Thread 	(bool kernel, void* start_addr, void * codeframe, int code_frame_num): queue_link(nullptr), isKernel(kernel), start(start_addr), id(idCounter++), kill_flag(false){
+Thread::Thread 	(bool kernel, void* start_addr, void * codeframe, int code_frame_num): queue_link(nullptr), isKernel(kernel), start(start_addr), code_paddr(codeframe), code_pagenum(code_frame_num), id(idCounter++), kill_flag(false){
 	StackPointer.isr = reinterpret_cast<void *>((uintptr_t)PageFrameAllocator::alloc(true)+STACK_SIZE);// mapped due to identity mapping
-	StackPointer.user = (void*)(0x61FF000+STACK_SIZE);
+	StackPointer.user = (void*)(0x6000000+STACK_SIZE);
 
-	map_app(codeframe, code_frame_num, StackPointer.user, 1);
+	map_app(codeframe, code_frame_num, (void*)((uintptr_t)StackPointer.user-STACK_SIZE), 1);
 
 	prepareContext(StackPointer.isr, context, kickoff, reinterpret_cast<uintptr_t>(this), 0, 0);
 }

kernel/thread/thread.h

@@ -57,7 +57,6 @@ class Thread {
 	/*! \brief Context of the thread, used for saving and restoring the register
 	 * values when context switching.
 	 */
-	Context context;
 
 	/*! \brief The thread's entry point.
 	 *
@@ -87,9 +86,11 @@ class Thread {
 	} StackPointer;
 	void* operator new  ( size_t count )noexcept;
 
+	Context context;
 	four_lvl_paging_t* paging_tree;
-	pagetable_t* appcode_table;
+
-	pagetable_t* appstack_table;
+	void* code_paddr;
+	int code_pagenum;
 
 	Semaphore ipc_sem;
 	Queue<IpcStruct> ipc_queue;

notes

@@ -31,3 +31,6 @@
                         |           |
                         |           |
                       schedule(2)   kickoff
+
+
+p/x ((pagetable_t*)(((pagetable_t*)(((pagetable_t*)(child.paging_tree.l4.entries[0].address<<12)).entries[0].address<<12)).entries[0].address<<12)).entries[0]

user/app1/appl.cc

@@ -45,13 +45,23 @@ extern "C" void main() {
 
 	//sys_test(1,2,3,4,5);
 
+	fork();
+
 	unsigned id = sys_getpid();
 	char text[] = "appX";
 	text[3] = 0x30+id;
-
 	write(1, text, sizeof(text), 0, (int)id);
-
 	uint8_t cnt = 0;
+
+	while(1){
+		cnt = (cnt+1)%100;
+		char msg[12];
+		char* num = itoa(cnt, msg);
+		write(1, num, strlen(num), 10, (int)id);
+		sleep(100);
+	}
+
+
 	for (uint8_t i = 1;; ++i) {
 		//counter to see app running
 		cnt=(cnt+1)%100;