Debug scheduler

src/boucane.cc

@@ -123,7 +123,7 @@ extern "C" void boucane(u64 mb_info){
         mem/=1024;
         printk("RAM:%dMB\n", mem);
     }
-    show_ticks=1;
+    //show_ticks=1;
     create_task((void*)task1, 50);
     create_task((void*)task2, 50);
     scheduler_start();

src/core/idt.cc

@@ -45,7 +45,7 @@ void idt_enable_interrupt(void){
             d2.ign=0;
             d2.ist=0;
             d2.selector=0x08;
-            d2.options=IDT_OPT_P|IDT_OPT_PRVL_3|IDT_OPT_TYPE_INT;
+            d2.options=IDT_OPT_P|IDT_OPT_PRVL_3|IDT_OPT_TYPE_TRAP;
             d2.offset=(u64)&INT_SYSCALL;
             idt_write_descriptor(d2, i);
         }

src/core/scheduler.cc

@@ -20,30 +20,35 @@ void schedule(){
     // to the clock() %rbp value and then we access to the registers SAVE_REGS in int.S
     u64* stack;
     asm("mov %%rbp, %%rax;mov (%%rax), %%rbx; add $16, %%rbx; mov %%rbx,%0": "=m"(stack)::"rax","rbx");
-    
+
     // Save current task
     PROC *t=&procs[active_process];
-    t->registers.r8=stack[0];
-    t->registers.r9=stack[1];
-    t->registers.r10=stack[2];
-    t->registers.r11=stack[3];
-    t->registers.r12=stack[4];
-    t->registers.r13=stack[5];
-    t->registers.r14=stack[6];
+    t->registers.rdi=stack[0];
+    t->registers.rsi=stack[1];
+    t->registers.rbp=stack[2];
+    t->registers.rdx=stack[3];
+    t->registers.rcx=stack[4];
+    t->registers.rbx=stack[5];
+    t->registers.rax=stack[6];
     t->registers.r15=stack[7];
-    t->registers.rdi=stack[8];
-    t->registers.rsi=stack[9];
-    t->registers.rbp=stack[10];
-    t->registers.rdx=stack[11];
-    t->registers.rcx=stack[12];
-    t->registers.rbx=stack[13];
-    t->registers.rax=stack[14];
+    t->registers.r14=stack[8];
+    t->registers.r13=stack[9];
+    t->registers.r12=stack[10];
+    t->registers.r11=stack[11];
+    t->registers.r10=stack[12];
+    t->registers.r9=stack[13];
+    t->registers.r8=stack[14];
     t->registers.rip=stack[15];
     t->registers.cs=stack[16];
     t->registers.eflags=stack[17];
     t->registers.rsp=stack[18];
-    t->registers.ds=stack[19];
+    t->registers.ss=stack[19];
+    if (t->registers.cs!=0x8)
+        t->registers.ds=0x23;
+    else
+        t->registers.ds=0x10;
 
+    //printk("Old task %d     cs:%x  rsp:%x   ds:%x\n ",active_process+1, t->registers.cs,t->registers.rsp,t->registers.ds);
     // Goto next task
     active_process++;
     if(active_process>=nproc)
@@ -54,7 +59,7 @@ void schedule(){
 
     // Clock acknownledgement
     apic_ack();
-    
+
     asm volatile(
         "mov %0, %%rdi       \n\t"  
         "jmp switch          \n\t"
@@ -84,6 +89,7 @@ void create_task(void* task, u32 size){
     t->registers.rip=TASK_VMA;
     t->registers.cs=0x1B; // 0x18 and 0x3 privilege
     t->registers.ds=0x23; // 0x20 and 0x3 privilege
+    t->registers.ss=0;    // Always 0 in long-mode
 
     // Load task using
     lpml4(t->pml4);

src/core/scheduler.hpp

@@ -11,14 +11,14 @@
 // DO NOT CHANGE THE FOLLOWING STRUCTURE WITHOUT CONCIDERING UPDATING
 // THE SWITCH FUNCTION INTO scheduler_asm.S
 typedef struct {
-    u64 rax, rbx, rcx, rdx;
-    u64 cs, rip;
-    u64 ss, rsp, rbp;
-    u64 rsi, rdi;
-    u64 ds, es, fs, gs;
-    u64 eflags;
-    u64 rsp0;
-    u64 r8,r9,r10,r11,r12,r13,r14,r15;
+    u64 rax, rbx, rcx, rdx;  // 8 16 24 32
+    u64 cs, rip;             // 40 48
+    u64 ss, rsp, rbp;        // 56 64 72
+    u64 rsi, rdi;            // 80 88
+    u64 ds, es, fs, gs;      // 96 104 112 120
+    u64 eflags;              // 128
+    u64 rsp0;                // 136
+    u64 r8,r9,r10,r11,r12,r13,r14,r15; // 144 152 160 168 176 184 192 200
 } __attribute__((packed)) REGS;
 
 // DO NOT CHANGE THE FOLLOWING STRUCTURE WITHOUT CONCIDERING UPDATING

src/core/scheduler_asm.S

@@ -1,34 +1,67 @@
 .globl switch
 
-
-
-.extern kvar_stack_pma
-
 switch:
-
-    # TODO: Check if we come from kernel mode (use kernel stack)
-    # TODO: restore all registers
-
-    mov 96(%rdi), %ax
-    mov %ax, %ds
-    mov %ax, %es
-    mov %ax, %fs
-    mov %ax, %gs
-   
+  
+    # Load task page table
     mov (%rdi), %rax
     mov %rax, %cr3
 
-    push 96(%rdi)
-    push 64(%rdi)
-    pushf
+    # First load the task stack
+    mov 64(%rdi), %rsp
+
+    # Prepare for iret
+    push 96(%rdi)   # ds
+    push 64(%rdi)   # rsp
+    push 128(%rdi)  # Flags
     pop %rax
     or $0x200, %rax # Enable interrupt
     mov $0xffffffffbfff, %rbx # NT flag
     and %rbx, %rax
-    push %rax
-    push 40(%rdi)
-    push 48(%rdi)
+    push %rax       # Apply flags changes
+    push 40(%rdi)   # cs
+    push 48(%rdi)   # rip
 
+    # Prepare to restore general registers
+    push 8(%rdi)    # rax
+    push 16(%rdi)   # rbx
+    push 24(%rdi)   # rcx
+    push 32(%rdi)   # rdx
+    push 72(%rdi)   # rbp
+    push 80(%rdi)   # rsi
+    push 88(%rdi)   # rdi
+    push 144(%rdi)  # r8
+    push 152(%rdi)  # r9
+    push 160(%rdi)  # r10
+    push 160(%rdi)  # r11
+    push 176(%rdi)  # r12
+    push 184(%rdi)  # r13
+    push 192(%rdi)  # r14
+    push 200(%rdi)  # r15
 
+    # ds
+    mov 96(%rdi), %ax
+    mov %ax, %ds
+    mov %ax, %gs
+    mov %ax, %fs
+    mov %ax, %es
+
+    # Restore general registers
+    pop %r15
+    pop %r14
+    pop %r13
+    pop %r12
+    pop %r11
+    pop %r10
+    pop %r9
+    pop %r8
+    pop %rdi
+    pop %rsi
+    pop %rbp
+    pop %rdx
+    pop %rcx
+    pop %rbx
+    pop %rax
+
+ 
     # Perform task switching
     iretq