/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2008 by Maurus Cuelenaere
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
 
#include "config.h"
#include "jz4740.h"
#include "mips.h"
#include "mmu-mips.h"
#include "panic.h"
#include "system.h"
#include "kernel.h"

#define EXTENDED_EXCEPTION_DESC 0
#if EXTENDED_EXCEPTION_DESC
#include "backlight-target.h"
#include "font.h"
#include "lcd.h"
#include "sprintf.h"
#endif

#define NUM_DMA  6
#define NUM_GPIO 128
#define IRQ_MAX  (IRQ_GPIO_0 + NUM_GPIO)

static int irq;
static void UIRQ(void)
{
    panicf("Unhandled interrupt occurred: %d", irq);
}

#define intr(name) extern __attribute__((weak,alias("UIRQ"))) void name (void)

intr(I2C);intr(EMC);intr(UHC);intr(UART0);intr(SADC);intr(MSC);intr(RTC);
intr(SSI);intr(CIM);intr(AIC);intr(ETH);intr(TCU2);intr(TCU1);intr(TCU0);
intr(UDC);intr(IPU);intr(LCD);

intr(DMA0);intr(DMA1);intr(DMA2);intr(DMA3);intr(DMA4);intr(DMA5);

intr(GPIO0);intr(GPIO1);intr(GPIO2);intr(GPIO3);intr(GPIO4);intr(GPIO5);
intr(GPIO6);intr(GPIO7);intr(GPIO8);intr(GPIO9);intr(GPIO10);intr(GPIO11);
intr(GPIO12);intr(GPIO13);intr(GPIO14);intr(GPIO15);intr(GPIO16);intr(GPIO17);
intr(GPIO18);intr(GPIO19);intr(GPIO20);intr(GPIO21);intr(GPIO22);intr(GPIO23);
intr(GPIO24);intr(GPIO25);intr(GPIO26);intr(GPIO27);intr(GPIO28);intr(GPIO29);
intr(GPIO30);intr(GPIO31);intr(GPIO32);intr(GPIO33);intr(GPIO34);intr(GPIO35);
intr(GPIO36);intr(GPIO37);intr(GPIO38);intr(GPIO39);intr(GPIO40);intr(GPIO41);
intr(GPIO42);intr(GPIO43);intr(GPIO44);intr(GPIO45);intr(GPIO46);intr(GPIO47);
intr(GPIO48);intr(GPIO49);intr(GPIO50);intr(GPIO51);intr(GPIO52);intr(GPIO53);
intr(GPIO54);intr(GPIO55);intr(GPIO56);intr(GPIO57);intr(GPIO58);intr(GPIO59);
intr(GPIO60);intr(GPIO61);intr(GPIO62);intr(GPIO63);intr(GPIO64);intr(GPIO65);
intr(GPIO66);intr(GPIO67);intr(GPIO68);intr(GPIO69);intr(GPIO70);intr(GPIO71);
intr(GPIO72);intr(GPIO73);intr(GPIO74);intr(GPIO75);intr(GPIO76);intr(GPIO77);
intr(GPIO78);intr(GPIO79);intr(GPIO80);intr(GPIO81);intr(GPIO82);intr(GPIO83);
intr(GPIO84);intr(GPIO85);intr(GPIO86);intr(GPIO87);intr(GPIO88);intr(GPIO89);
intr(GPIO90);intr(GPIO91);intr(GPIO92);intr(GPIO93);intr(GPIO94);intr(GPIO95);
intr(GPIO96);intr(GPIO97);intr(GPIO98);intr(GPIO99);intr(GPIO100);intr(GPIO101);
intr(GPIO102);intr(GPIO103);intr(GPIO104);intr(GPIO105);intr(GPIO106);
intr(GPIO107);intr(GPIO108);intr(GPIO109);intr(GPIO110);intr(GPIO111);
intr(GPIO112);intr(GPIO113);intr(GPIO114);intr(GPIO115);intr(GPIO116);
intr(GPIO117);intr(GPIO118);intr(GPIO119);intr(GPIO120);intr(GPIO121);
intr(GPIO122);intr(GPIO123);intr(GPIO124);intr(GPIO125);intr(GPIO126);
intr(GPIO127);

static void (* const irqvector[])(void) =
{
    I2C,EMC,UHC,UIRQ,UIRQ,UIRQ,UIRQ,UIRQ,
    UART0,UIRQ,UIRQ,SADC,UIRQ,MSC,RTC,SSI,
    CIM,AIC,ETH,UIRQ,TCU2,TCU1,TCU0,UDC,
    UIRQ,UIRQ,UIRQ,UIRQ,IPU,LCD,UIRQ,DMA0,
    DMA1,DMA2,DMA3,DMA4,DMA5,UIRQ,UIRQ,UIRQ,
    UIRQ,UIRQ,UIRQ,UIRQ,UIRQ,UIRQ,UIRQ,
    GPIO0,GPIO1,GPIO2,GPIO3,GPIO4,GPIO5,GPIO6,GPIO7,
    GPIO8,GPIO9,GPIO10,GPIO11,GPIO12,GPIO13,GPIO14,GPIO15,
    GPIO16,GPIO17,GPIO18,GPIO19,GPIO20,GPIO21,GPIO22,GPIO23,
    GPIO24,GPIO25,GPIO26,GPIO27,GPIO28,GPIO29,GPIO30,GPIO31,
    GPIO32,GPIO33,GPIO34,GPIO35,GPIO36,GPIO37,GPIO38,GPIO39,
    GPIO40,GPIO41,GPIO42,GPIO43,GPIO44,GPIO45,GPIO46,GPIO47,
    GPIO48,GPIO49,GPIO50,GPIO51,GPIO52,GPIO53,GPIO54,GPIO55,
    GPIO56,GPIO57,GPIO58,GPIO59,GPIO60,GPIO61,GPIO62,GPIO63,
    GPIO64,GPIO65,GPIO66,GPIO67,GPIO68,GPIO69,GPIO70,GPIO71,
    GPIO72,GPIO73,GPIO74,GPIO75,GPIO76,GPIO77,GPIO78,GPIO79,
    GPIO80,GPIO81,GPIO82,GPIO83,GPIO84,GPIO85,GPIO86,GPIO87,
    GPIO88,GPIO89,GPIO90,GPIO91,GPIO92,GPIO93,GPIO94,GPIO95,
    GPIO96,GPIO97,GPIO98,GPIO99,GPIO100,GPIO101,GPIO102,GPIO103,
    GPIO104,GPIO105,GPIO106,GPIO107,GPIO108,GPIO109,GPIO110,GPIO111,
    GPIO112,GPIO113,GPIO114,GPIO115,GPIO116,GPIO117,GPIO118,GPIO119,
    GPIO120,GPIO121,GPIO122,GPIO123,GPIO124,GPIO125,GPIO126,GPIO127
};

static unsigned int dma_irq_mask = 0;
static unsigned int gpio_irq_mask[4] = {0};

void system_enable_irq(unsigned int irq)
{
    register unsigned int t;
    if ((irq >= IRQ_GPIO_0) && (irq <= IRQ_GPIO_0 + NUM_GPIO))
    {
        __gpio_unmask_irq(irq - IRQ_GPIO_0);
        t = (irq - IRQ_GPIO_0) >> 5;
        gpio_irq_mask[t] |= (1 << ((irq - IRQ_GPIO_0) & 0x1f));
        __intc_unmask_irq(IRQ_GPIO0 - t);
    }
    else if ((irq >= IRQ_DMA_0) && (irq <= IRQ_DMA_0 + NUM_DMA))
    {
        __dmac_channel_enable_irq(irq - IRQ_DMA_0);
        dma_irq_mask |= (1 << (irq - IRQ_DMA_0));
        __intc_unmask_irq(IRQ_DMAC);
    }
    else if (irq < 32)
        __intc_unmask_irq(irq);
}

static void dis_irq(unsigned int irq)
{
    register unsigned int t;
    if ((irq >= IRQ_GPIO_0) && (irq <= IRQ_GPIO_0 + NUM_GPIO))
    {
        __gpio_mask_irq(irq - IRQ_GPIO_0);
        t = (irq - IRQ_GPIO_0) >> 5;
        gpio_irq_mask[t] &= ~(1 << ((irq - IRQ_GPIO_0) & 0x1f));
        if (!gpio_irq_mask[t])
            __intc_mask_irq(IRQ_GPIO0 - t);
    }
    else if ((irq >= IRQ_DMA_0) && (irq <= IRQ_DMA_0 + NUM_DMA))
    {
        __dmac_channel_disable_irq(irq - IRQ_DMA_0);
        dma_irq_mask &= ~(1 << (irq - IRQ_DMA_0));
        if (!dma_irq_mask)
            __intc_mask_irq(IRQ_DMAC);
    }
    else if (irq < 32)
        __intc_mask_irq(irq);
}

static void ack_irq(unsigned int irq)
{
    if ((irq >= IRQ_GPIO_0) && (irq <= IRQ_GPIO_0 + NUM_GPIO))
    {
        __intc_ack_irq(IRQ_GPIO0 - ((irq - IRQ_GPIO_0)>>5));
        __gpio_ack_irq(irq - IRQ_GPIO_0);
    }
    else if ((irq >= IRQ_DMA_0) && (irq <= IRQ_DMA_0 + NUM_DMA))
        __intc_ack_irq(IRQ_DMAC);
    else if (irq < 32)
        __intc_ack_irq(irq);
}

static int get_irq_number(void)
{
    static unsigned long ipl;
    register int irq;
    
    ipl |= REG_INTC_IPR;
    
    if (UNLIKELY(ipl == 0))
        return -1;

    __asm__ __volatile__("negu  $8, %0        \n"
                         "and   $8, %0, $8    \n"
                         "clz   %0, %1        \n"
                         "li    $8, 31        \n"
                         "subu  %0, $8, %0    \n"
                         : "=r" (irq)
                         : "r" (ipl)
                         : "t0"
                        );
    
    if (UNLIKELY(irq < 0))
        return -1;

    ipl &= ~(1 << irq);

    switch (irq)
    {
        case IRQ_GPIO0:
            irq = __gpio_group_irq(0) + IRQ_GPIO_0;
            break;
        case IRQ_GPIO1:
            irq = __gpio_group_irq(1) + IRQ_GPIO_0 + 32;
            break;
        case IRQ_GPIO2:
            irq = __gpio_group_irq(2) + IRQ_GPIO_0 + 64;
            break;
        case IRQ_GPIO3:
            irq = __gpio_group_irq(3) + IRQ_GPIO_0 + 96;
            break;
        case IRQ_DMAC:
            irq = __dmac_get_irq() + IRQ_DMA_0;
            break;
    }

    return irq;
}

void intr_handler(void)
{
    register int irq = get_irq_number();
    if(UNLIKELY(irq < 0))
        return;
    
    ack_irq(irq);
    if(LIKELY(irq > 0))
        irqvector[irq-1]();
}

#define EXC(x,y) case (x): return (y);
static char* parse_exception(unsigned int cause)
{
    switch(cause & M_CauseExcCode)
    {
        EXC(EXC_INT, "Interrupt");
        EXC(EXC_MOD, "TLB Modified");
        EXC(EXC_TLBL, "TLB Exception (Load or Ifetch)");
        EXC(EXC_ADEL, "Address Error (Load or Ifetch)");
        EXC(EXC_ADES, "Address Error (Store)");
        EXC(EXC_TLBS, "TLB Exception (Store)");
        EXC(EXC_IBE, "Instruction Bus Error");
        EXC(EXC_DBE, "Data Bus Error");
        EXC(EXC_SYS, "Syscall");
        EXC(EXC_BP, "Breakpoint");
        EXC(EXC_RI, "Reserved Instruction");
        EXC(EXC_CPU, "Coprocessor Unusable");
        EXC(EXC_OV, "Overflow");
        EXC(EXC_TR, "Trap Instruction");
        EXC(EXC_FPE, "Floating Point Exception");
        EXC(EXC_C2E, "COP2 Exception");
        EXC(EXC_MDMX, "MDMX Exception");
        EXC(EXC_WATCH, "Watch Exception");
        EXC(EXC_MCHECK, "Machine Check Exception");
        EXC(EXC_CacheErr, "Cache error caused re-entry to Debug Mode");
        default:
            return NULL;
    }
}

void exception_handler(void* stack_ptr, unsigned int cause, unsigned int epc)
{
#if EXTENDED_EXCEPTION_DESC
    (void)epc;

    /* Depends on crt0.S ! */
    char buffer[LCD_WIDTH/SYSFONT_WIDTH];
    char *registers[] = { "ra", "fp", "gp", "t9", "t8", "s7", "s6", "s5", "s4",
                          "s3", "s2", "s1", "s0", "t7", "t6", "t5", "t4", "t3",
                          "t2", "t1", "t0", "a3", "a2", "a1", "a0", "v1", "v0",
                          "$1", "LO", "HI", "STATUS", "EPC" };
    int i;

    lcd_set_backdrop(NULL);
    lcd_clear_display();
    lcd_setfont(FONT_SYSFIXED);
    _backlight_on();

    snprintf(buffer, sizeof(buffer), "0x%08x at 0x%08x", read_c0_badvaddr(), epc);
    lcd_puts(0, 0, parse_exception(cause));
    lcd_puts(0, 1, buffer);
    for(i=0; i< 0x80/4; i+=2)
    {
        unsigned int* ptr = (unsigned int*)(stack_ptr + i*4);
        snprintf(buffer, sizeof(buffer), "%s: 0x%08x %s: 0x%08x", registers[i], *ptr, registers[i+1], *(ptr+1));
        lcd_puts(0, 3 + i/2, buffer);
    }
    lcd_update();

    system_exception_wait();
#else
    panicf("Exception occurred: %s [0x%08x] at 0x%08x (stack at 0x%08x)", parse_exception(cause), read_c0_badvaddr(), epc, (unsigned int)stack_ptr);
#endif
}

void tlb_refill_handler(void)
{
    panicf("TLB refill handler at 0x%08lx! [0x%x]", read_c0_epc(), read_c0_badvaddr());
}

void udelay(unsigned int usec)
{
    unsigned int i = usec * (__cpm_get_cclk() / 2000000);
    __asm__ __volatile__ (
                          ".set noreorder    \n"
                          "1:                \n"
                          "bne  %0, $0, 1b   \n"
                          "addi %0, %0, -1   \n"
                          ".set reorder      \n"
                          : "=r" (i)
                          : "0" (i)
                          );
}

void mdelay(unsigned int msec)
{
    unsigned int i;
    for(i=0; i<msec; i++)
        udelay(1000);
}

static int dma_count = 0;
void dma_enable(void)
{
    if(++dma_count == 1)
    {
        __cpm_start_dmac();
        
        REG_DMAC_DCCSR(0) = 0;
        REG_DMAC_DCCSR(1) = 0;
        REG_DMAC_DCCSR(2) = 0;
        REG_DMAC_DCCSR(3) = 0;
        REG_DMAC_DCCSR(4) = 0;
        REG_DMAC_DCCSR(5) = 0;
        
        REG_DMAC_DMACR = (DMAC_DMACR_PR_RR | DMAC_DMACR_DMAE);
    }
}

void dma_disable(void)
{
    if(--dma_count == 0)
    {
        REG_DMAC_DMACR &= ~DMAC_DMACR_DMAE;
        __cpm_stop_dmac();
    }
}

/* PLL output clock = EXTAL * NF / (NR * NO)
 *
 * NF = FD + 2, NR = RD + 2
 * NO = 1 (if OD = 0), NO = 2 (if OD = 1 or 2), NO = 4 (if OD = 3)
 */
static void pll_init(void) ICODE_ATTR;
static void pll_init(void)
{
    register unsigned int cfcr, plcr1;
    int n2FR[33] = {
        0, 0, 1, 2, 3, 0, 4, 0, 5, 0, 0, 0, 6, 0, 0, 0,
        7, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0,
        9
    };
    int div[5] = {0, 3, 3, 3, 3}; /* divisors of I:S:P:L:M */
    int nf, pllout2;

    cfcr = CPM_CPCCR_CLKOEN |
        CPM_CPCCR_PCS |
        (n2FR[div[0]] << CPM_CPCCR_CDIV_BIT) |
        (n2FR[div[1]] << CPM_CPCCR_HDIV_BIT) |
        (n2FR[div[2]] << CPM_CPCCR_PDIV_BIT) |
        (n2FR[div[3]] << CPM_CPCCR_MDIV_BIT) |
        (n2FR[div[4]] << CPM_CPCCR_LDIV_BIT) |
        CPM_CPCCR_CE; /* Perform clock divisions immediately */

    pllout2 = (cfcr & CPM_CPCCR_PCS) ? CPU_FREQ : (CPU_FREQ / 2);

    /* Init USB Host clock, pllout2 must be n*48MHz */
    REG_CPM_UHCCDR = pllout2 / 48000000 - 1;

    nf = CPU_FREQ * 2 / CFG_EXTAL;
    plcr1 = ((nf - 2) << CPM_CPPCR_PLLM_BIT) | /* FD */
        (0 << CPM_CPPCR_PLLN_BIT) |     /* RD=0, NR=2 */
        (0 << CPM_CPPCR_PLLOD_BIT) |    /* OD=0, NO=1 */
        (0x20 << CPM_CPPCR_PLLST_BIT) | /* PLL stable time */
        CPM_CPPCR_PLLEN;                /* enable PLL */          

    /* init PLL */
    REG_CPM_CPCCR = cfcr;
    REG_CPM_CPPCR = plcr1;
}

// SDRAM paramters
#define CFG_SDRAM_BW16      0    /* Data bus width: 0-32bit, 1-16bit */
#define CFG_SDRAM_BANK4     1    /* Banks each chip: 0-2bank, 1-4bank */
#define CFG_SDRAM_ROW       12   /* Row address: 11 to 13 */
#define CFG_SDRAM_COL       8    /* Column address: 8 to 12 */
#define CFG_SDRAM_CASL      2    /* CAS latency: 2 or 3 */

// SDRAM Timings, unit: ns
#define CFG_SDRAM_TRAS      45    /* RAS# Active Time */
#define CFG_SDRAM_RCD       20    /* RAS# to CAS# Delay */
#define CFG_SDRAM_TPC       20    /* RAS# Precharge Time */
#define CFG_SDRAM_TRWL      7     /* Write Latency Time */
#define CFG_SDRAM_TREF      7812  /* Refresh period: 8192 refresh cycles/64ms */

/*
 * Init SDRAM memory.
 */
static void sdram_init(void) ICODE_ATTR;
static void sdram_init(void)
{
    register unsigned int dmcr0, dmcr, sdmode, tmp, cpu_clk, mem_clk, ns;

    unsigned int cas_latency_sdmr[2] = {
        EMC_SDMR_CAS_2,
        EMC_SDMR_CAS_3,
    };

    unsigned int cas_latency_dmcr[2] = {
        1 << EMC_DMCR_TCL_BIT,  /* CAS latency is 2 */
        2 << EMC_DMCR_TCL_BIT   /* CAS latency is 3 */
    };

    int div[] = { 1, 2, 3, 4, 6, 8, 12, 16, 24, 32 };

    cpu_clk = CPU_FREQ;
    mem_clk = cpu_clk * div[__cpm_get_cdiv()] / div[__cpm_get_mdiv()];

    //REG_EMC_BCR = 0;      /* Disable bus release */
    REG_EMC_RTCSR = 0;          /* Disable clock for counting */
    REG_EMC_RTCOR = 0;
    REG_EMC_RTCNT = 0;

    /* Fault DMCR value for mode register setting */
#define SDRAM_ROW0    11
#define SDRAM_COL0     8
#define SDRAM_BANK40   0

    dmcr0 = ((SDRAM_ROW0 - 11) << EMC_DMCR_RA_BIT) |
        ((SDRAM_COL0 - 8) << EMC_DMCR_CA_BIT) |
        (SDRAM_BANK40 << EMC_DMCR_BA_BIT) |
        (CFG_SDRAM_BW16 << EMC_DMCR_BW_BIT) |
        EMC_DMCR_EPIN | cas_latency_dmcr[((CFG_SDRAM_CASL == 3) ? 1 : 0)];

    /* Basic DMCR value */
    dmcr = ((CFG_SDRAM_ROW - 11) << EMC_DMCR_RA_BIT) |
        ((CFG_SDRAM_COL - 8) << EMC_DMCR_CA_BIT) |
        (CFG_SDRAM_BANK4 << EMC_DMCR_BA_BIT) |
        (CFG_SDRAM_BW16 << EMC_DMCR_BW_BIT) |
        EMC_DMCR_EPIN | cas_latency_dmcr[((CFG_SDRAM_CASL == 3) ? 1 : 0)];

    /* SDRAM timimg */
    ns = 1000000000 / mem_clk;
    tmp = CFG_SDRAM_TRAS / ns;
    if (tmp < 4)
        tmp = 4;
    if (tmp > 11)
        tmp = 11;
    dmcr |= ((tmp - 4) << EMC_DMCR_TRAS_BIT);
    tmp = CFG_SDRAM_RCD / ns;
    if (tmp > 3)
        tmp = 3;
    dmcr |= (tmp << EMC_DMCR_RCD_BIT);
    tmp = CFG_SDRAM_TPC / ns;
    if (tmp > 7)
        tmp = 7;
    dmcr |= (tmp << EMC_DMCR_TPC_BIT);
    tmp = CFG_SDRAM_TRWL / ns;
    if (tmp > 3)
        tmp = 3;
    dmcr |= (tmp << EMC_DMCR_TRWL_BIT);
    tmp = (CFG_SDRAM_TRAS + CFG_SDRAM_TPC) / ns;
    if (tmp > 14)
        tmp = 14;
    dmcr |= (((tmp + 1) >> 1) << EMC_DMCR_TRC_BIT);

    /* SDRAM mode value */
    sdmode = EMC_SDMR_BT_SEQ |
        EMC_SDMR_OM_NORMAL |
        EMC_SDMR_BL_4 | cas_latency_sdmr[((CFG_SDRAM_CASL == 3) ? 1 : 0)];

    /* Stage 1. Precharge all banks by writing SDMR with DMCR.MRSET=0 */
    REG_EMC_DMCR = dmcr;
    REG8(EMC_SDMR0 | sdmode) = 0;

    /* Wait for precharge, > 200us */
    tmp = (cpu_clk / 1000000) * 1000;
    while (tmp--);

    /* Stage 2. Enable auto-refresh */
    REG_EMC_DMCR = dmcr | EMC_DMCR_RFSH;

    tmp = CFG_SDRAM_TREF / ns;
    tmp = tmp / 64 + 1;
    if (tmp > 0xff)
        tmp = 0xff;
    REG_EMC_RTCOR = tmp;
    REG_EMC_RTCNT = 0;
    REG_EMC_RTCSR = EMC_RTCSR_CKS_64;   /* Divisor is 64, CKO/64 */

    /* Wait for number of auto-refresh cycles */
    tmp = (cpu_clk / 1000000) * 1000;
    while (tmp--);

    /* Stage 3. Mode Register Set */
    REG_EMC_DMCR = dmcr0 | EMC_DMCR_RFSH | EMC_DMCR_MRSET;
    REG8(EMC_SDMR0 | sdmode) = 0;

    /* Set back to basic DMCR value */
    REG_EMC_DMCR = dmcr | EMC_DMCR_RFSH | EMC_DMCR_MRSET;

    /* everything is ok now */
}

/* Gets called *before* main */
void ICODE_ATTR system_main(void)
{
    int i;
       
    __dcache_writeback_all();
    __icache_invalidate_all();
    
    write_c0_status(1 << 28 | 1 << 10 ); /* Enable CP | Mask interrupt 2 */
    
    /* Disable all interrupts */
    for(i=0; i<IRQ_MAX; i++)
        dis_irq(i);
    
    mmu_init();
    pll_init();
    sdram_init();
    
    /* Disable unneeded clocks, clocks are enabled when needed */
    __cpm_stop_all();
    __cpm_suspend_usbhost();
    
    /* Enable interrupts at core level */
    enable_interrupt();
}

void system_reboot(void)
{
    REG_WDT_TCSR = WDT_TCSR_PRESCALE4 | WDT_TCSR_EXT_EN;
    REG_WDT_TCNT = 0;
    REG_WDT_TDR = JZ_EXTAL/1000;   /* reset after 4ms */
    REG_TCU_TSCR = TCU_TSSR_WDTSC; /* enable wdt clock */
    REG_WDT_TCER = WDT_TCER_TCEN;  /* wdt start */
    
    while (1);
}

void system_exception_wait(void)
{
    /* check for power button without including any .h file */
    while(1)
    {
        if( (~REG_GPIO_PXPIN(3)) & (1 << 29) )
            return;
        asm volatile("nop");
    }
}

void power_off(void)
{
    /* Enable RTC clock */
    __cpm_start_rtc();
    
    /* Put system into hibernate mode */
    __rtc_clear_alarm_flag();
    __rtc_clear_hib_stat_all();
    /* __rtc_set_scratch_pattern(0x12345678); */
    __rtc_enable_alarm_wakeup();
    __rtc_set_hrcr_val(0xFE0);
    __rtc_set_hwfcr_val(0xFFFF << 4);
    __rtc_power_down();
    
    while(1);
}

void system_init(void)
{
}

int system_memory_guard(int newmode)
{
    (void)newmode;
    return 0;
}

#ifdef HAVE_ADJUSTABLE_CPU_FREQ
void set_cpu_frequency(long frequency)
{
    unsigned long cfcr = REG_CPM_CPCCR;
    cfcr &= ~CPM_CPCCR_CDIV_MASK;

    if(frequency == CPUFREQ_NORMAL)
        cfcr |= (0 << CPM_CPCCR_CDIV_BIT);
    else
        cfcr |= (2 << CPM_CPCCR_CDIV_BIT);

    REG_CPM_CPCCR = cfcr;
    cpu_frequency = frequency;
}
#endif