timer interrupts

defs.h

@@ -37,7 +37,10 @@ void pic_init(void);
 void mp_init(void);
 int cpu(void);
 int mp_isbcpu(void);
-void lapic_init(int c);
+void lapic_init(int);
+void lapic_timerinit(void);
+void lapic_timerintr(void);
+void lapic_enableintr(void);
 
 // spinlock.c
 extern uint32_t kernel_lock;

main.c

@@ -36,11 +36,11 @@ main()
 
   cprintf("\nxV6\n\n");
 
+  pic_init(); // initialize PIC---not clear why
   mp_init(); // multiprocessor
   kinit(); // physical memory allocator
   tvinit(); // trap vectors
   idtinit(); // CPU's idt
-  pic_init();
 
   // create fake process zero
   p = &proc[0];
@@ -59,47 +59,18 @@ main()
   p->ppid = 0;
   setupsegs(p);
 
-  // turn on interrupts
-  irq_setmask_8259A(0xff);
+  // turn on interrupts on boot processor
+  lapic_timerinit();
+  lapic_enableintr();
   write_eflags(read_eflags() | FL_IF);
 
 #if 0
   ide_read(0, buf, 1);
   cprintf("sec0.0 %x\n", buf[0] & 0xff);
 #endif
 
-#if 1
   p = newproc();
   load_icode(p, _binary_usertests_start, (unsigned) _binary_usertests_size);
-#endif
-
-#if 0
-  i = 0;
-  p->mem[i++] = 0x90; // nop 
-  p->mem[i++] = 0xb8; // mov ..., %eax
-  p->mem[i++] = SYS_fork;
-  p->mem[i++] = 0;
-  p->mem[i++] = 0;
-  p->mem[i++] = 0;
-  p->mem[i++] = 0xcd; // int
-  p->mem[i++] = T_SYSCALL;
-  p->mem[i++] = 0xb8; // mov ..., %eax
-  p->mem[i++] = SYS_wait;
-  p->mem[i++] = 0;
-  p->mem[i++] = 0;
-  p->mem[i++] = 0;
-  p->mem[i++] = 0xcd; // int
-  p->mem[i++] = T_SYSCALL;
-  p->mem[i++] = 0xb8; // mov ..., %eax
-  p->mem[i++] = SYS_exit;
-  p->mem[i++] = 0;
-  p->mem[i++] = 0;
-  p->mem[i++] = 0;
-  p->mem[i++] = 0xcd; // int
-  p->mem[i++] = T_SYSCALL;
-  p->tf->tf_eip = 0;
-  p->tf->tf_esp = p->sz;
-#endif
 
   swtch();
 
@@ -109,32 +80,32 @@ main()
 void
 load_icode(struct proc *p, uint8_t *binary, unsigned size)
 {
-	int i;
-	struct Elf *elf;
-	struct Proghdr *ph;
+  int i;
+  struct Elf *elf;
+  struct Proghdr *ph;
 
-	// Check magic number on binary
-	elf = (struct Elf*) binary;
-        cprintf("elf %x magic %x\n", elf, elf->e_magic);
-	if (elf->e_magic != ELF_MAGIC)
-		panic("load_icode: not an ELF binary");
+  // Check magic number on binary
+  elf = (struct Elf*) binary;
+  cprintf("elf %x magic %x\n", elf, elf->e_magic);
+  if (elf->e_magic != ELF_MAGIC)
+    panic("load_icode: not an ELF binary");
 
   p->tf->tf_eip = elf->e_entry;
   p->tf->tf_esp = p->sz;
 
-	// Map and load segments as directed.
-	ph = (struct Proghdr*) (binary + elf->e_phoff);
-	for (i = 0; i < elf->e_phnum; i++, ph++) {
-		if (ph->p_type != ELF_PROG_LOAD)
-			continue;
-                cprintf("va %x memsz %d\n", ph->p_va, ph->p_memsz);
-		if (ph->p_va + ph->p_memsz < ph->p_va)
-			panic("load_icode: overflow in elf header segment");
-		if (ph->p_va + ph->p_memsz >= p->sz)
-			panic("load_icode: icode wants to be above UTOP");
-
-		// Load/clear the segment
-		memcpy(p->mem + ph->p_va, binary + ph->p_offset, ph->p_filesz);
-		memset(p->mem + ph->p_va + ph->p_filesz, 0, ph->p_memsz - ph->p_filesz);
-	}
+  // Map and load segments as directed.
+  ph = (struct Proghdr*) (binary + elf->e_phoff);
+  for (i = 0; i < elf->e_phnum; i++, ph++) {
+    if (ph->p_type != ELF_PROG_LOAD)
+      continue;
+    cprintf("va %x memsz %d\n", ph->p_va, ph->p_memsz);
+    if (ph->p_va + ph->p_memsz < ph->p_va)
+      panic("load_icode: overflow in elf header segment");
+    if (ph->p_va + ph->p_memsz >= p->sz)
+      panic("load_icode: icode wants to be above UTOP");
+
+    // Load/clear the segment
+    memcpy(p->mem + ph->p_va, binary + ph->p_offset, ph->p_filesz);
+    memset(p->mem + ph->p_va + ph->p_filesz, 0, ph->p_memsz - ph->p_filesz);
+  }
 }

mp.c

@@ -4,6 +4,7 @@
 #include "memlayout.h"
 #include "param.h"
 #include "x86.h"
+#include "traps.h"
 #include "mmu.h"
 
 /* 
@@ -115,12 +116,33 @@ lapic_write(int r, int data)
   *(lapicaddr+(r/sizeof(*lapicaddr))) = data;
 }
 
+
+void
+lapic_timerinit()
+{
+  cprintf("%d: init timer\n", cpu());
+  lapic_write(LAPIC_TDCR, LAPIC_X1);
+  lapic_write(LAPIC_TIMER, LAPIC_CLKIN | LAPIC_PERIODIC | (IRQ_OFFSET + IRQ_TIMER));
+  lapic_write(LAPIC_TCCR, 1000000);
+  lapic_write(LAPIC_TICR, 1000000);
+}
+
+void
+lapic_timerintr()
+{
+  cprintf("%d: timer interrupt!\n", cpu());
+  lapic_write (LAPIC_EOI, 0);
+}
+
 void
 lapic_init(int c)
 {
   uint32_t r, lvt;
 
   cprintf("lapic_init %d\n", c);
+
+  irq_setmask_8259A(0xFFFF);
+
   lapic_write(LAPIC_DFR, 0xFFFFFFFF);
   r = (lapic_read(LAPIC_ID)>>24) & 0xFF;
   lapic_write(LAPIC_LDR, (1<<r)<<24);
@@ -152,19 +174,11 @@ lapic_init(int c)
   while(lapic_read(LAPIC_ICRLO) & APIC_DELIVS)
     ;
 
-  /*
-   * Do not allow acceptance of interrupts until all initialisation
-   * for this processor is done. For the bootstrap processor this can be
-   * early duing initialisation. For the application processors this should
-   * be after the bootstrap processor has lowered priority and is accepting
-   * interrupts.
-   */
-  lapic_write(LAPIC_TPR, 0);
   cprintf("Done init of an apic\n");
 }
 
-static void
-lapic_online(void) 
+void
+lapic_enableintr(void) 
 {
   lapic_write(LAPIC_TPR, 0);
 }
@@ -274,7 +288,7 @@ mp_detect(void)
   if(sum || (pcmp->version != 1 && pcmp->version != 4))
     return 3;
 
-  cprintf("MP spec rev #: %x\n", mp->specrev);
+  cprintf("Mp spec rev #: %x\n", mp->specrev);
   return 0;
 }
 
@@ -348,8 +362,6 @@ mp_init()
   lapic_init(bcpu-cpus);
   cprintf("ncpu: %d boot %d\n", ncpu, bcpu-cpus);
 
-  lapic_online();
-
   extern uint8_t _binary_bootother_start[], _binary_bootother_size[];
   memmove((void *) APBOOTCODE,_binary_bootother_start, 
 	  (uint32_t) _binary_bootother_size);

mp.h

@@ -109,15 +109,15 @@ enum {
   APIC_NMI = 0x00000400,
   APIC_INIT = 0x00000500,	/* INIT/RESET */
   APIC_STARTUP = 0x00000600,	/* Startup IPI */
-  APIC_ExtINT = 0x00000700,
+  APIC_EXTINT = 0x00000700,
 
   APIC_PHYSICAL = 0x00000000,	/* [11] Destination Mode (RW) */
   APIC_LOGICAL = 0x00000800,
 
   APIC_DELIVS = 0x00001000,	/* [12] Delivery Status (RO) */
   APIC_HIGH = 0x00000000,	/* [13] Interrupt Input Pin Polarity (RW) */
   APIC_LOW = 0x00002000,
-  APIC_RemoteIRR	= 0x00004000,	/* [14] Remote IRR (RO) */
+  APIC_REMOTEIRR	= 0x00004000,	/* [14] Remote IRR (RO) */
   APIC_EDGE = 0x00000000,	/* [15] Trigger Mode (RW) */
   APIC_LEVEL = 0x00008000,
   APIC_IMASK = 0x00010000,	/* [16] Interrupt Mask */

trap.c

@@ -43,14 +43,15 @@ trap(struct Trapframe *tf)
     return;
   }
 
-  cprintf("trap %d eip %x:%x\n", tf->tf_trapno, tf->tf_cs, tf->tf_eip);
-
-  if(v == 32){
-    // probably clock
+  if(v == (IRQ_OFFSET + IRQ_TIMER)){
+    curproc[cpu()]->tf = tf;
+    lapic_timerintr();
     return;
   }
 
-  while(1)
-    ;
+  cprintf("trap %d eip %x:%x\n", tf->tf_trapno, tf->tf_cs, tf->tf_eip);
+
   // XXX probably ought to lgdt on trap return
+
+  return;
 }

traps.h

@@ -24,3 +24,9 @@
 // processor defined exceptions or interrupt vectors.
 #define T_SYSCALL   48		// system call
 #define T_DEFAULT   500		// catchall
+
+#define IRQ_OFFSET      32	// IRQ 0 corresponds to int IRQ_OFFSET
+
+#define IRQ_TIMER       18
+#define IRQ_ERROR       19
+#define IRQ_SPURIOUS    31