update pic32 port

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1478 bbd45198-f89e-11dd-88c7-29a3b14d5316

libcpu/mips/pic32/context_gcc.S

+#include <p32xxxx.h>
+#include "../common/mips.inc"
+#include "../common/stackframe.h"
+
+    .section ".text", "ax"
+	.set 		noat
+    .set noreorder
+
 /*
  * rt_base_t rt_hw_interrupt_disable()
  */
     .globl rt_hw_interrupt_disable
 rt_hw_interrupt_disable:
+    mfc0    v0, CP0_STATUS    /* v0 = status */
+    addiu   v1, zero,   -2    /* v1 = 0-2 = 0xFFFFFFFE */
+    and     v1, v0, v1        /* v1 = v0 & 0xFFFFFFFE */
+    mtc0    v1, CP0_STATUS    /* status = v1 */
+    jr      ra
+    nop
 
 /*
  * void rt_hw_interrupt_enable(rt_base_t level)
  */
     .globl rt_hw_interrupt_enable
 rt_hw_interrupt_enable:
+    mtc0    a0, CP0_STATUS
+    jr      ra
+    nop
 
 /*
  * void rt_hw_context_switch_to(rt_uint32 to)/*
@@ -16,6 +33,9 @@ rt_hw_interrupt_enable:
  */
     .globl rt_hw_context_switch_to
 rt_hw_context_switch_to:
+    lw      sp, 0(a0)       /* get new task stack pointer */
+
+    RESTORE_ALL_AND_RET
 
 /*
  * void rt_hw_context_switch(rt_uint32 from, rt_uint32 to)
@@ -24,6 +44,13 @@ rt_hw_context_switch_to:
  */
     .globl rt_hw_context_switch
 rt_hw_context_switch:
+    mtc0    ra, CP0_EPC
+    SAVE_ALL
+
+    sw      sp, 0(a0)       /* store sp in preempted tasks TCB */
+    lw      sp, 0(a1)       /* get new task stack pointer */
+
+    RESTORE_ALL_AND_RET
 
 /*
  * void rt_hw_context_switch_interrupt(rt_uint32 from, rt_uint32 to)/*
@@ -33,4 +60,64 @@ rt_hw_context_switch:
     .globl rt_interrupt_to_thread
     .globl rt_hw_context_switch_interrupt
 rt_hw_context_switch_interrupt:
+    la      t0, rt_thread_switch_interrput_flag
+    lw      t1, 0(t0)
+    nop
+    bnez    t1, _reswitch
+    nop
+    li      t1, 0x01                       /* set rt_thread_switch_interrput_flag to 1 */
+    sw      t1, 0(t0)
+    la      t0, rt_interrupt_from_thread   /* set rt_interrupt_from_thread */
+    sw      a0, 0(t0)
+_reswitch:
+    la      t0, rt_interrupt_to_thread     /* set rt_interrupt_to_thread */
+    sw      a1, 0(t0)
+
+    /* trigger the soft exception (causes context switch) */
+    mfc0    t0, CP0_CAUSE                  /* t0 = Cause */
+    ori     t0, t0, (1<<8)                 /* t0 |= (1<<8) */
+    mtc0    t0, CP0_CAUSE                  /* cause = t0 */
+    addiu   t1,	zero,   -257               /* t1 = ~(1<<8) */
+    and     t0, t0, t1                     /* t0 &= t1 */
+    mtc0    t0, CP0_CAUSE                  /* cause = t0 */
+    jr      ra
+    nop
+
+/*
+ * void __ISR(_CORE_SOFTWARE_0_VECTOR, ipl2) CoreSW0Handler(void)
+ */
+    .section ".text", "ax"
+    .set noreorder
+	.set 		noat
+ 	.ent		CoreSW0Handler
+
+	    .globl CoreSW0Handler
+CoreSW0Handler:
+			SAVE_ALL
+
+			/* mCS0ClearIntFlag(); */
+			la      t0, IFS0CLR             /* t0 = IFS0CLR */
+			addiu   t1,zero,0x02            /* t1 = (1<<2) */
+			sw      t1, 0(t0)               /* IFS0CLR = t1 */
+
+			/* tol rd2 */
+			lui         v1,0xbf88
+			addiu       v0,zero,(1<<0)
+			sw          v0,24812(v1)
+
+    /*
+     * switch to the new thread
+     */
+    la      k0, rt_interrupt_from_thread
+    lw      k1, 0(k0)
+    nop
+    sw      sp, 0(k1)                       /* store sp in preempted tasks's TCB */
+
+    la      k0, rt_interrupt_to_thread
+    lw      k1, 0(k0)
+    nop
+    lw      sp, 0(k1)                       /* get new task's stack pointer */
+
+    RESTORE_ALL_AND_RET
 
+	.end		CoreSW0Handler

libcpu/mips/pic32/interrupt.c

@@ -14,3 +14,14 @@
 
 #include <rtthread.h>
 
+/**
+ * @addtogroup PIC32
+ */
+/*@{*/
+
+rt_uint32_t rt_interrupt_from_thread, rt_interrupt_to_thread;
+rt_uint32_t rt_thread_switch_interrput_flag;
+
+
+/*@}*/
+

libcpu/mips/pic32/stack.c

@@ -15,10 +15,20 @@
 #include <rtthread.h>
 
 /**
- * @addtogroup Loogonson SoC3210
+ * @addtogroup PIC32
  */
 /*@{*/
 
+rt_uint32_t __attribute__((nomips16)) _get_gp(void)
+{
+    rt_uint32_t result;
+
+    // get the gp reg
+    asm volatile("move   %0, $28" : "=r"(result));
+
+    return result;
+}
+
 /**
  * This function will initialize thread stack
  *
@@ -33,6 +43,47 @@ rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter, rt_uint8_t *stack_ad
 {
 	rt_uint32_t *stk;
 
+    /** Start at stack top */
+    stk = (rt_uint32_t *)stack_addr;
+	*(stk)   = (rt_uint32_t) tentry;        /* pc: Entry Point */
+	*(--stk) = (rt_uint32_t) 0x00800000;    /* c0_cause: IV=1, */
+	*(--stk) = (rt_uint32_t) 0;		        /* c0_badvaddr */
+	*(--stk) = (rt_uint32_t) 0;             /* lo */
+	*(--stk) = (rt_uint32_t) 0;	            /* hi */
+	*(--stk) = (rt_uint32_t) 1; 			/* C0_SR: IE = En, */
+	*(--stk) = (rt_uint32_t) texit;	        /* 31 ra */
+	*(--stk) = (rt_uint32_t) 0x0000001e;	/* 30 s8 */
+	*(--stk) = (rt_uint32_t) stack_addr;	/* 29 sp */
+	*(--stk) = (rt_uint32_t) _get_gp();     /* 28 gp */
+	*(--stk) = (rt_uint32_t) 0x0000001b;	/* 27 k1 */
+	*(--stk) = (rt_uint32_t) 0x0000001a;	/* 26 k0 */
+	*(--stk) = (rt_uint32_t) 0x00000019;	/* 25 t9 */
+	*(--stk) = (rt_uint32_t) 0x00000018;	/* 24 t8 */
+	*(--stk) = (rt_uint32_t) 0x00000017;	/* 23 s7 */
+	*(--stk) = (rt_uint32_t) 0x00000016;	/* 22 s6 */
+	*(--stk) = (rt_uint32_t) 0x00000015;	/* 21 s5 */
+	*(--stk) = (rt_uint32_t) 0x00000014;	/* 20 s4 */
+	*(--stk) = (rt_uint32_t) 0x00000013;	/* 19 s3 */
+	*(--stk) = (rt_uint32_t) 0x00000012;	/* 18 s2 */
+	*(--stk) = (rt_uint32_t) 0x00000011;	/* 17 s1 */
+	*(--stk) = (rt_uint32_t) 0x00000010;	/* 16 s0 */
+	*(--stk) = (rt_uint32_t) 0x0000000f;	/* 15 t7 */
+	*(--stk) = (rt_uint32_t) 0x0000000e;	/* 14 t6 */
+	*(--stk) = (rt_uint32_t) 0x0000000d;	/* 13 t5 */
+	*(--stk) = (rt_uint32_t) 0x0000000c;	/* 12 t4 */
+	*(--stk) = (rt_uint32_t) 0x0000000b;	/* 11 t3 */
+	*(--stk) = (rt_uint32_t) 0x0000000a; 	/* 10 t2 */
+	*(--stk) = (rt_uint32_t) 0x00000009;	/* 9 t1 */
+	*(--stk) = (rt_uint32_t) 0x00000008;	/* 8 t0 */
+	*(--stk) = (rt_uint32_t) 0x00000007;	/* 7 a3 */
+	*(--stk) = (rt_uint32_t) 0x00000006;	/* 6 a2 */
+	*(--stk) = (rt_uint32_t) 0x00000005;	/* 5 a1 */
+	*(--stk) = (rt_uint32_t) parameter;	    /* 4 a0 */
+	*(--stk) = (rt_uint32_t) 0x00000003;	/* 3 v1 */
+	*(--stk) = (rt_uint32_t) 0x00000002;	/* 2 v0 */
+	*(--stk) = (rt_uint32_t) 0x00000001;	/* 1 at */
+	*(--stk) = (rt_uint32_t) 0x00000000;	/* 0 zero */
+
 	/* return task's current stack address */
 	return (rt_uint8_t *)stk;
 }