1 /* 2 * File : cpuport.c 3 * This file is part of RT-Thread RTOS 4 * COPYRIGHT (C) 2009 - 2011, RT-Thread Development Team 5 * 6 * The license and distribution terms for this file may be 7 * found in the file LICENSE in this distribution or at 8 * http://www.rt-thread.org/license/LICENSE 9 * 10 * Change Logs: 11 * Date Author Notes 12 * 20011-05-23 aozima the first version for PIC32. 13 * 20011-09-05 aozima merge all of C source code into cpuport.c. 14 */ 15 #include <rtthread.h> 16 17 /** 18 * @addtogroup PIC32 19 */ 20 /*@{*/ 21 22 /* exception and interrupt handler table */ 23 rt_uint32_t rt_interrupt_from_thread, rt_interrupt_to_thread; 24 rt_uint32_t rt_thread_switch_interrupt_flag; 25 26 rt_uint32_t __attribute__((nomips16)) _get_gp(void) 27 { 28 rt_uint32_t result; 29 30 // get the gp reg 31 asm volatile("move %0, $28" : "=r"(result)); 32 33 return result; 34 } 35 36 /** 37 * This function will initialize thread stack 38 * 39 * @param tentry the entry of thread 40 * @param parameter the parameter of entry 41 * @param stack_addr the beginning stack address 42 * @param texit the function will be called when thread exit 43 * 44 * @return stack address 45 */ 46 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter, rt_uint8_t *stack_addr, void *texit) 47 { 48 rt_uint32_t *stk; 49 50 /** Start at stack top */ 51 stk = (rt_uint32_t *)stack_addr; 52 *(stk) = (rt_uint32_t) tentry; /* pc: Entry Point */ 53 *(--stk) = (rt_uint32_t) 0x00800000; /* c0_cause: IV=1, */ 54 *(--stk) = (rt_uint32_t) 0; /* c0_badvaddr */ 55 *(--stk) = (rt_uint32_t) 0; /* lo */ 56 *(--stk) = (rt_uint32_t) 0; /* hi */ 57 *(--stk) = (rt_uint32_t) 1; /* C0_SR: IE = En, */ 58 *(--stk) = (rt_uint32_t) texit; /* 31 ra */ 59 *(--stk) = (rt_uint32_t) 0x0000001e; /* 30 s8 */ 60 *(--stk) = (rt_uint32_t) stack_addr; /* 29 sp */ 61 *(--stk) = (rt_uint32_t) _get_gp(); /* 28 gp */ 62 *(--stk) = (rt_uint32_t) 0x0000001b; /* 27 k1 */ 63 *(--stk) = (rt_uint32_t) 0x0000001a; /* 26 k0 */ 64 *(--stk) = (rt_uint32_t) 0x00000019; /* 25 t9 */ 65 *(--stk) = (rt_uint32_t) 0x00000018; /* 24 t8 */ 66 *(--stk) = (rt_uint32_t) 0x00000017; /* 23 s7 */ 67 *(--stk) = (rt_uint32_t) 0x00000016; /* 22 s6 */ 68 *(--stk) = (rt_uint32_t) 0x00000015; /* 21 s5 */ 69 *(--stk) = (rt_uint32_t) 0x00000014; /* 20 s4 */ 70 *(--stk) = (rt_uint32_t) 0x00000013; /* 19 s3 */ 71 *(--stk) = (rt_uint32_t) 0x00000012; /* 18 s2 */ 72 *(--stk) = (rt_uint32_t) 0x00000011; /* 17 s1 */ 73 *(--stk) = (rt_uint32_t) 0x00000010; /* 16 s0 */ 74 *(--stk) = (rt_uint32_t) 0x0000000f; /* 15 t7 */ 75 *(--stk) = (rt_uint32_t) 0x0000000e; /* 14 t6 */ 76 *(--stk) = (rt_uint32_t) 0x0000000d; /* 13 t5 */ 77 *(--stk) = (rt_uint32_t) 0x0000000c; /* 12 t4 */ 78 *(--stk) = (rt_uint32_t) 0x0000000b; /* 11 t3 */ 79 *(--stk) = (rt_uint32_t) 0x0000000a; /* 10 t2 */ 80 *(--stk) = (rt_uint32_t) 0x00000009; /* 9 t1 */ 81 *(--stk) = (rt_uint32_t) 0x00000008; /* 8 t0 */ 82 *(--stk) = (rt_uint32_t) 0x00000007; /* 7 a3 */ 83 *(--stk) = (rt_uint32_t) 0x00000006; /* 6 a2 */ 84 *(--stk) = (rt_uint32_t) 0x00000005; /* 5 a1 */ 85 *(--stk) = (rt_uint32_t) parameter; /* 4 a0 */ 86 *(--stk) = (rt_uint32_t) 0x00000003; /* 3 v1 */ 87 *(--stk) = (rt_uint32_t) 0x00000002; /* 2 v0 */ 88 *(--stk) = (rt_uint32_t) 0x00000001; /* 1 at */ 89 *(--stk) = (rt_uint32_t) 0x00000000; /* 0 zero */ 90 91 /* return task's current stack address */ 92 return (rt_uint8_t *)stk; 93 } 94 95 96 /*@}*/ 97