f'd myself over of course, scheduler can now run user programs....

build_and_run.sh

@@ -0,0 +1,23 @@
+#!/bin/bash 
+
+# cd rocklibc 
+# make clean
+# make
+# cd .. 
+
+cd programs 
+make clean
+make
+cd .. 
+
+make clean 
+make
+
+cd initrd
+./make_img.sh
+cd ..
+
+make -B
+
+make run
+

clean.sh

@@ -2,20 +2,16 @@
 
 cd rocklibc 
 make clean
-make
 cd .. 
 
 cd programs 
 make clean
-make
 cd .. 
 
 make clean 
-make
 
 cd initrd
-./make_img.sh
+rm -rf output
+rm *.elf
 cd ..
 
-make -B
-

kernel/interrupts.S

@@ -18,10 +18,22 @@ isr\num:
 isr_common_stub:
     pushal             
 
+    xor %eax, %eax
+    mov %ds, %ax    
+    pushl %eax
+
+    mov $0x10, %ax
+    mov %ax, %ds
+    mov %ax, %es
+
     pushl %esp         
     call common_interrupt_handler
     addl $4, %esp      
 
+    popl %eax
+    mov %ax, %ds
+    mov %ax, %es
+
     popal              
     addl $8, %esp      
     iret            
@@ -44,17 +56,28 @@ ISR_ERRCODE   14   # Page Fault (Has Error Code!)
 .extern send_eoi_master     # drivers/pic/pic.S
 isr32:
     cli
-    pushal 
+    pushal
+    call send_eoi_master
+
+    xor %eax, %eax
+    mov %ds, %ax
+    pushl %eax
+
+    mov $0x10, %ax
+    mov %ax, %ds
+    mov %ax, %es
     
     pushl %esp 
     call switch_context
     movl %eax, %esp 
 
-    call send_eoi_master
+    popl %eax
+    mov %ax, %ds
+    mov %ax, %es
 
     popal
     sti
-    iret 
+    iret
 
 ISR_NOERRCODE 33   # IRQ1 - Keyboard
 

kernel/interrupts.c

@@ -29,15 +29,6 @@ typedef struct __attribute__((packed)) {
     uint32_t base;
 } idt_ptr;
 
-typedef struct __attribute__((packed)) {
-    uint32_t edi, esi, ebp, dummy, ebx, edx, ecx, eax;
-    
-    uint32_t int_no;    
-    uint32_t error_code;
-    
-    uint32_t eip, cs, eflags, u_esp, u_ss;
-} intr_regs_t;
-
 // (interrupts.S)
 extern void load_idt(void);
 extern void isr0();
@@ -89,7 +80,7 @@ void init_idt() {
         if (isr_stub_table[i] != 0) {
             set_idtr(i, isr_stub_table[i], SEGMENT_KERN, ATTR_KERN_32);
         } else {
-            set_idtr(i, 0, SEGMENT_KERN, 0);
+            set_idtr(i, 0, SEGMENT_KERN, ATTR_KERN_32);
         }
     }
 
@@ -98,6 +89,15 @@ void init_idt() {
     load_idt();
 }
 
+typedef struct __attribute__((packed)) {
+    uint32_t ds;
+    uint32_t edi, esi, ebp, dummy, ebx, edx, ecx, eax;
+    
+    uint32_t int_no;    
+    uint32_t error_code;
+    
+    uint32_t eip, cs, eflags, u_esp, u_ss;
+} intr_regs_t;
 void common_interrupt_handler(intr_regs_t *args) {
     switch (args->int_no) {
         case 0:
@@ -116,7 +116,6 @@ void common_interrupt_handler(intr_regs_t *args) {
         case 13:
         case 15:
         case 16:
-            asm volatile("cli");
             kprintf("\n--- CPU Exception ---\n");
             kprintf("Error: [%d] %s\n", args->int_no, err_messages[args->int_no]);
             kprintf("Error Code: 0x%x\n", args->error_code);
@@ -125,10 +124,10 @@ void common_interrupt_handler(intr_regs_t *args) {
             kprintf("EAX: 0x%x\n", args->eax);
             kprintf("EFLAGS: 0x%x\n", args->eflags);
             kprintf("Code Segment: 0x%x\n", args->cs);
+            kprintf("Calling Data Segment: 0x%x\n", args->ds);
             kprintf("Current cr3: 0x%x\n", fetch_cr3());
             kprintf("tss.esp0: 0x%x\n", tss.esp0);
-            process_t* task = current_task();
+            kprintf("instruction: 0x%x\n", *(uint32_t*)args->eip);
-            kprintf("Task kstack_top: 0x%x\n", task->kstack_top);
             asm volatile("hlt");
             break;
         case 14:{
@@ -154,6 +153,10 @@ void common_interrupt_handler(intr_regs_t *args) {
             asm volatile("hlt");
             break;
         }
+        case 32: {
+
+            break;
+        }
         case 33: {
             kprintf("ps2 keyboard interrupt\n");
             uint8_t data = ps2_read_data();

kernel/scheduler.c

@@ -69,17 +69,13 @@ uint32_t switch_context(uint32_t current_esp) {
 
     uint32_t current_cr3 = fetch_cr3();
     if (current_cr3 != process_table[current_process].cr3) {
-        kprintf("switching cr3 | old: 0x%x | new: 0x%x\n", current_cr3, process_table[current_process].cr3);
         load_pd((void*)process_table[current_process].cr3);
     }
 
     if (process_table[current_process].flags & PROCESS_FLAG_USER) {
         tss.esp0 = process_table[current_process].kstack_top;
     }
-
+    
-    if (found_ready) {
-        kprintf("found ready task %d | cr3: 0x%x\n", current_process, process_table[current_process].cr3);
-    }
     return process_table[current_process].esp;
 }
 
@@ -123,12 +119,12 @@ int create_task(uint32_t entry_point, uint32_t cr3, int user, uint32_t u_esp) {
     if (user) {
         *(--esp) = 0x23;            // User Data Segment (SS) with RPL 3 (0x20 | 3)
         *(--esp) = u_esp;           // User Stack Pointer (ESP) - location mapped in user space
-        *(--esp) = 0x0202;          // EFLAGS (Interrupts enabled)
+        *(--esp) = 0x202;          // EFLAGS (Interrupts enabled)
         *(--esp) = 0x1B;            // User Code Segment (CS) with RPL 3 (0x18 | 3)
         *(--esp) = entry_point;     // EIP
     } else {
         // IRET values for Ring 0
-        *(--esp) = 0x0202;          // EFLAGS
+        *(--esp) = 0x202;          // EFLAGS
         *(--esp) = 0x08;            // Kernel Code Segment (CS)
         *(--esp) = entry_point;     // EIP
     }
@@ -142,6 +138,12 @@ int create_task(uint32_t entry_point, uint32_t cr3, int user, uint32_t u_esp) {
     *(--esp) = 0;             // ESI
     *(--esp) = 0;             // EDI
 
+    if (user) {
+        *(--esp) = 0x23;            // User Data Segment Selector (RPL 3)
+    } else {
+        *(--esp) = 0x10;            // Kernel Data Segment Selector (RPL 0)
+    }
+
     process->esp = (uint32_t)esp;
     return 1;
 }

kernel/syscall.S

@@ -4,33 +4,33 @@
 syscall_handler: 
     cli
 
-    pushfl          
+    push $0
-    pushl %cs
+    push $0x80
 
-    movl 8(%esp), %eax      
+    pusha
-    pushl %eax
-    movl 4(%esp), %ebx      # Get CS
-    movl %ebx, 8(%esp)      # Move CS over Old EIP
-    movl 0(%esp), %ebx      # Get Return EIP
-    movl %ebx, 4(%esp)      # Move Return EIP over CS
-    addl $4, %esp           # Adjust stack pointer
 
-    movw %ds, %ax
+    push %ds
-    pushl %eax
+    push %es
+    push %fs
+    push %gs
 
-    pushal
+    mov $0x10, %ax               
-
+    mov %ax, %ds
-    pushl %esp
+    mov %ax, %es
-    call switch_context
+    mov %ax, %fs
-    movl %eax, %esp
+    mov %ax, %gs
-
-    popal
     
-    popl %eax
+    push %esp
-    movw %ax, %ds
+    call syscall
-    movw %ax, %es
+    add $4, %esp
-    movw %ax, %fs
+    
-    movw %ax, %gs
+    mov 28(%esp), %eax
 
-    sti
+    pop %gs
+    pop %fs
+    pop %es
+    pop %ds
+
+    popa
+    add $8, %esp
     iret

kernel/syscall.c

@@ -18,6 +18,7 @@ typedef struct registers {
 
 
 static int32_t sys_exit(int status) {
+    asm volatile("cli");
     asm volatile("hlt");
     return 0;
 }

programs/crt0.S

@@ -1,7 +1,7 @@
 .global _start
 
 .section .text
-_start:
+_start: 
     xor %ebp, %ebp
     push %ebp
     mov %esp, %ebp
@@ -13,9 +13,10 @@ _start:
     push %ecx
     push %ebx
     push %eax
-1: jmp 1b  
+
     call main
 
     push %eax
+1: jmp 1b  
     call exit
-1: jmp 1b   
+

programs/main.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-int main() {
+int main(int argc, char *argv[]) {
     printf("RockOS booting...\n");
     return 0;
 }

programs/makefile

@@ -21,4 +21,4 @@ $(TARGET): crt0.o main.o ../rocklibc/rlibc.a
 clean:
 	rm -f *.o $(TARGET)
 
-.PHONY: all clean
+.PHONY: all clean test

rocklibc/src/rockos/syscall.c

@@ -96,7 +96,7 @@ void * sbrk(intptr_t increment) {
 
     if (increment == 0) {
          return (void *)current_break; 
-    }
+    }                
 
     uint32_t new_break = (uint32_t)((intptr_t)current_break + increment);
     
@@ -109,6 +109,6 @@ void * sbrk(intptr_t increment) {
     return (void *)-1;
 }
 
-void exit(int status) {
+void _exit(int status) {
     _PDCLIB_exit(status);
 }