[pk, sim] added interrupt support to sim; added timer interrupt

pk/entry.S

@@ -116,7 +116,17 @@ pop_tf:	# write the trap frame onto the stack
 	eret
 	.end	pop_tf
 
-
+	#define TIMER_IRQ_HANDLER \
+	.align	7; \
+	mtpcr	$x2,ASM_CR(PCR_K0); \
+	mtpcr	$x1,ASM_CR(PCR_K1); \
+	mfpcr	$x1,ASM_CR(PCR_COMPARE); \
+	liw		$x2,TIMER_PERIOD; \
+	addw	$x1,$x1,$x2; \
+	mtpcr	$x1,ASM_CR(PCR_COMPARE); \
+	mfpcr	$x1,ASM_CR(PCR_K1); \
+	mfpcr	$x2,ASM_CR(PCR_K0); \
+	eret
 
 	#define TRAP_TABLE_ENTRY(x) \
 	.align	7; \
@@ -150,6 +160,14 @@ trap_table:
 	TRAP_TABLE_ENTRY(handle_badtrap)
 	TRAP_TABLE_ENTRY(handle_badtrap)
 	TRAP_TABLE_ENTRY(handle_badtrap)
+	TRAP_TABLE_ENTRY(handle_badtrap)
+	TRAP_TABLE_ENTRY(handle_badtrap)
+	TRAP_TABLE_ENTRY(handle_badtrap)
+	TRAP_TABLE_ENTRY(handle_badtrap)
+	TRAP_TABLE_ENTRY(handle_badtrap)
+	TRAP_TABLE_ENTRY(handle_badtrap)
+	TRAP_TABLE_ENTRY(handle_badtrap)
+	TIMER_IRQ_HANDLER
 	.align	12
 	.end	trap_table
 

pk/pcr.h

@@ -8,18 +8,22 @@
 #define SR_S     0x0000000000000008
 #define SR_EF    0x0000000000000010
 #define SR_UX    0x0000000000000020
-#define SR_KX    0x0000000000000040
+#define SR_SX    0x0000000000000040
 #define SR_IM    0x000000000000FF00
 
 #define PCR_SR       0
 #define PCR_EPC      1
 #define PCR_BADVADDR 2
 #define PCR_TBR      3
+#define PCR_COUNT    4
+#define PCR_COMPARE  5
 #define PCR_TOHOST   16
 #define PCR_FROMHOST 17
 #define PCR_K0       24
 #define PCR_K1       25
 
+#define TIMER_PERIOD 0x1000000
+
 #define ASM_CR(r)   _ASM_CR(r)
 #define _ASM_CR(r)  $cr##r
 

pk/riscv-pk.c

@@ -5,19 +5,19 @@ void __attribute__((section(".boottext"))) __start()
   extern char stack_top;
   asm("move $sp,%0" : : "r"(&stack_top-64));
 
-  register long sr0 = SR_S | SR_PS | SR_ET;
+  extern char trap_table;
+  register void* tt = &trap_table;
+  mtpcr(tt,PCR_TBR);
+
+  register long sr0 = SR_S | SR_PS | SR_ET | SR_IM;
   #ifdef PK_ENABLE_KERNEL_64BIT
-    sr0 |= SR_KX;
+    sr0 |= SR_SX;
     #ifdef PK_ENABLE_USER_64BIT
       sr0 |= SR_UX;
     #endif
   #endif
   mtpcr(sr0,PCR_SR);
 
-  extern char trap_table;
-  register void* tt = &trap_table;
-  mtpcr(tt,PCR_TBR);
-
   extern void boot();
   register void (*boot_p)() = &boot;
   asm("" : "=r"(boot_p) : "0"(boot_p));