mmu_example.c

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/*This file has been prepared for Doxygen automatic documentation generation.*/
/* Copyright (c) 2006, Atmel Corporation All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. The name of ATMEL may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ATMEL ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND
 * SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <avr32/io.h>
#include <string.h>
#include <malloc.h>
#include <sys/exceptions.h>
#include "settings.h"
#include "macro.h"
#include "usart.h"
#include "mmu.h"

static int free_page_nr = 16;
static volatile avr32_pio_t *pioa = &AVR32_PIOA;
static volatile avr32_pio_t *piob = &AVR32_PIOB;
static volatile avr32_pio_t *pioc = &AVR32_PIOC;
static volatile avr32_usart_t *usart = &USART_MODULE;
static unsigned long handler_table[0x104];

unsigned int mmu_exception(int evba_offset, int return_address)
{
    int retval;
    long bear;
    long vpn;
    long pfn;
    struct mmu_tlb_t tlbOptions;
    tlbOptions.valid = MMU_ENABLE;
    tlbOptions.type = MMU_TLB_TYPE_DATA;
    tlbOptions.asid = 0;
    tlbOptions.cachable = MMU_DISABLE;
    tlbOptions.global = MMU_DISABLE;
    tlbOptions.bufferable = MMU_DISABLE;
    tlbOptions.access = 0x03; /* read/write/execute */
    tlbOptions.page_size = MMU_PAGE_SIZE_64KB;
    tlbOptions.dirty = MMU_ENABLE;
    tlbOptions.write_through = MMU_DISABLE;
    tlbOptions.position = -1;

    printf("\r\n* Handling exception: ");

    switch (evba_offset) {
    case EVBA_ITLB_MISS:
    case EVBA_DTLB_MISS_W:
    case EVBA_DTLB_MISS_R:
        mmu_read_bear_and_tlbehi(&bear, &vpn);
        printf("TLB miss at virtual address 0x%08lx\r\n", bear);
        printf("  Bear is 0x%08lx\r\n", bear);
        printf("  Vpn  is 0x%08lx\r\n", vpn);

        /* Add the page to TLB */
        if (free_page_nr > MMU_DTLB_ENTRIES) {
            free_page_nr = 16;
        }
        tlbOptions.position = free_page_nr++;
        printf("  Adding page to TLB[%02d]...  ", tlbOptions.position);
        /* in SRAM segment */
        if (((bear ^ 0x24000000) >> 24) == 0) {
            pfn = 0x24000000;
        } else {
            pfn = 0;
        }
        retval = mmu_add_tlb_entry(pfn, bear, &tlbOptions);
        if (retval != MMU_OK) {
            printf("[ FAILED ]\r\n");
            goto out;
        }
        printf("[ OK ]\r\n");
        break;
    default:
        printf("unhandled exception 0x%08x!\r\n", evba_offset);
    }

out:
    printf("\n");
    return return_address;
}


int mmuex_exceptions()
{
    int retval = MMU_OK;
    char * string_p = "this test string is used to generate exceptions";
    char * string_p61 = (char *)((long) string_p | 0x61800000);

    printf("\r\nDemonstrate MMU mode...\r\n");
    printf("  Segmentation: ON\r\n");
    printf("  Paging      : ON\r\n");
    printf("  Exceptions  : ON\r\n\n");

    /* Reset MMU */
    printf("  Reset MMU...               ");
    retval = mmu_reset();
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    /* Set shared mode */
    printf("  Set MMU in shared mode...  ");
    retval = mmu_init(MMU_DISABLE,
            MMU_SHARED_VIRTUAL_MODE,
            MMU_SEGMENTATION_ON);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    struct mmu_tlb_t tlbOptions;
    tlbOptions.valid = MMU_ENABLE;
    tlbOptions.type = MMU_TLB_TYPE_DATA;
    tlbOptions.asid = 0;
    tlbOptions.cachable = MMU_DISABLE;
    tlbOptions.global = MMU_DISABLE;
    tlbOptions.bufferable = MMU_DISABLE;
    tlbOptions.access = 0x03; /* read/write/execute */
    tlbOptions.page_size = MMU_PAGE_SIZE_64KB;
    tlbOptions.dirty = MMU_ENABLE;
    tlbOptions.write_through = MMU_DISABLE;
    tlbOptions.position = -1;

    /* Add the segments to TLB */

    /* Inset NOR flash at address 0 */
    printf("  Adding segments to TLB...  ");
    tlbOptions.position = 12;
    retval = mmu_add_tlb_entry(0, 0, &tlbOptions);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    /* Insert the internal SRAM */
    tlbOptions.position = 14;
    retval = mmu_add_tlb_entry(0x24000000, 0x24000000, &tlbOptions);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    /* Change mode */
    printf("  Changing mode...           ");
    retval = mmu_init(MMU_ENABLE,
            MMU_SHARED_VIRTUAL_MODE,
            MMU_SEGMENTATION_ON);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    printf("\r\n");
    printf("  String   (0x%08lx): %s\r\n", (long)string_p, string_p);
    /* Use the pointer in the 0x6180xxxx segment without adding the page.
     * This will generate an exception */
    strcpy(string_p61, string_p);

    /* Print out the string which should now be available */
    printf("  String61 (0x%08lx): %s\r\n", (long)string_p61, string_p61);

    printf("\r\n");
    printf("  Test result...             ");

    if (strcmp(string_p, string_p61) == 0) {
        printf("[ OK ]\r\n\n");
    } else {
        printf("[ FAILED ]\r\n\n");
    }

    return retval;
error:
    printf("\r\n");
    printf("  Test result... (jumped)    [ FAILED ]\r\n\n");
    return retval;
}


int mmuex_segon_pageon()
{
    int retval = MMU_OK;
    char * string_p = "MMU test segmentation on, paging on";
    long string_p64 = (long) string_p | 0x64080000;
    long string_pPA = 0;
    long string_pVA = 0;

    printf("\r\nDemonstrate MMU mode...\r\n");
    printf("  Segmentation: ON\r\n");
    printf("  Paging      : ON\r\n\n");

    /* Reset MMU */
    printf("  Reset MMU...               ");
    retval = mmu_reset();
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    /* Set shared mode */
    printf("  Set MMU in shared mode...  ");
    retval = mmu_init(MMU_DISABLE,
            MMU_SHARED_VIRTUAL_MODE,
            MMU_SEGMENTATION_ON);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    struct mmu_tlb_t tlbOptions;
    tlbOptions.valid = MMU_ENABLE;
    tlbOptions.type = MMU_TLB_TYPE_DATA;
    tlbOptions.asid = 0;
    tlbOptions.cachable = MMU_DISABLE;
    tlbOptions.global = MMU_DISABLE;
    tlbOptions.bufferable = MMU_DISABLE;
    tlbOptions.access = 0x03; /* read/write/execute */
    tlbOptions.page_size = MMU_PAGE_SIZE_64KB;
    tlbOptions.dirty = MMU_ENABLE;
    tlbOptions.write_through = MMU_DISABLE;
    tlbOptions.position = -1;

    /* Add the segments to TLB */
    printf("  Adding segments to TLB...  ");
    tlbOptions.position = 12;
    retval = mmu_add_tlb_entry(0, 0, &tlbOptions);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    tlbOptions.position = 14;
    retval = mmu_add_tlb_entry(0x24000000, 0x24000000, &tlbOptions);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }

    /* Add a memory address which maps to string_p */
    tlbOptions.position = 11;
    retval = mmu_add_tlb_entry((long)string_p, 0x64080000, &tlbOptions);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    /* Change mode */
    printf("  Changing mode...           ");
    retval = mmu_init(MMU_ENABLE,
            MMU_SHARED_VIRTUAL_MODE,
            MMU_SEGMENTATION_ON);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    /* Search and get the physical
     * address to the pointer
     */
    printf("  Lookup physical address... ");
    retval = mmu_search_virtual_ptr((void *)string_p64, &string_pPA);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    /* Search and get the virtual
     * address to the pointer
     */
    printf("  Lookup virtual address...  ");
    retval = mmu_search_physical_ptr((void *)string_pPA, &string_pVA);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    /* Find the index for the TLB entry */
    long tlbIndex;
    printf("  Get TLB index... ");
    retval = mmu_find_index_to_entry(string_pPA, string_pVA, &tlbIndex);
    if (retval != MMU_OK) {
        printf("          [ FAILED ]\r\n");
        goto error;
    }
    printf("[%02ld]      [ OK ]\r\n", tlbIndex);

    printf("\r\n");
    printf("  String   (0x%08lx): %s\r\n", (long)string_p, string_p);
    printf("  String64 (0x%08lx): %s\r\n", (long)string_p64, (char *)string_p64);
    printf("  StringPA (0x%08lx): %s\r\n", (long)string_pPA, (char *)string_pPA);
    printf("  StringVA (0x%08lx): %s\r\n", (long)string_pVA, (char *)string_pVA);
    printf("\r\n");
    printf("  Test result...             ");

    if (strcmp(string_p, (char *)string_pPA) == 0 &&
            strcmp(string_p, (char *)string_pVA) == 0) {
        printf("[ OK ]\r\n\n");
    } else {
        printf("[ FAILED ]\r\n\n");
    }

    return retval;
error:
    printf("\r\n");
    printf("  Test result... (jumped)    [ FAILED ]\r\n\n");
    return retval;
}


int mmuex_segon_pageoff()
{
    int retval = MMU_OK;
    char * string_p80 = 0;
    char * string_pA0 = 0;
    char * string_pC0 = 0;
    char * string_p = "MMU test segmentation off, paging on";

    printf("\r\nDemonstrate MMU mode...\r\n");
    printf("  Segmentation: ON\r\n");
    printf("  Paging      : OFF\r\n\n");

    /* Reset MMU */
    printf("  Reset MMU...               ");
    retval = mmu_reset();
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    /* Change mode */
    printf("  Changing mode...           ");
    retval = mmu_init(MMU_DISABLE,
            MMU_SHARED_VIRTUAL_MODE,
            MMU_SEGMENTATION_ON);
    if (retval != MMU_OK) {
        printf("[ FAILED ]\r\n");
        goto error;
    }
    printf("[ OK ]\r\n");

    string_p80 = (void*)(0x80000000|(long)string_p);
    string_pA0 = (void*)(0xA0000000|(long)string_p);
    string_pC0 = (void*)(0xC0000000|(long)string_p);

    printf("\r\n");
    printf("  String   (%08x): %s\r\n", (int)string_p, string_p);
    printf("  String80 (%08x): %s\r\n", (int)string_p80, string_p80);
    printf("  StringA0 (%08x): %s\r\n", (int)string_pA0, string_pA0);
    printf("  StringC0 (%08x): %s\r\n", (int)string_pC0, string_pC0);
    printf("\r\n");
    printf("  Test result...             ");

    if (strcmp(string_p, string_p80) == 0 &&
            strcmp(string_p, string_pA0) == 0 &&
            strcmp(string_p, string_pC0) == 0) {
        printf("[ OK ]\r\n\n");
    } else {
        printf("[ FAILED ]\r\n\n");
    }

    return retval;
error:
    printf("\r\n");
    printf("  Test result... (jumped)    [ FAILED ]\r\n\n");
    return retval;
}

extern char _evba[];

int main(int argc, char * argv[])
{
    int error = 0;

    /* set up exceptions */
    init_exceptions((void *)_evba, handler_table);
    _register_exception_handler(&mmu_exception, EVBA_ITLB_MISS);
    _register_exception_handler(&mmu_exception, EVBA_DTLB_MISS_R);
    _register_exception_handler(&mmu_exception, EVBA_DTLB_MISS_W);
    _register_exception_handler(&mmu_exception, EVBA_DTLB_MODIFIED);

    /* disable all interrupts on PIO */
    pioa->idr = 0xFFFFffff;
    piob->idr = 0xFFFFffff;
    pioc->idr = 0xFFFFffff;

    /* Enable USART on PIOA */
    pioa->pdr = AVR32_PIO_P17_MASK|AVR32_PIO_P18_MASK;
    pioa->asr = AVR32_PIO_P17_MASK|AVR32_PIO_P18_MASK;

    /* Enable PIO as debug output/input
     * Output: PC0 => PC15
     * Input : PB0 => PB7
     */
    piob->per = 0x000000FF;
    piob->odr = 0x000000FF;
    piob->ifer = 0x000000FF;
    piob->odsr = 0x00000000;
    piob->puer = 0x000000FF;

    pioc->per = 0x0000FFFF;
    pioc->oer = 0x0000FFFF;
    pioc->ower = 0x0000FFFF;
    pioc->odsr = 0x00000000;

    /* Set options for the USART */
    struct usart_options_t usartOptions;
    usartOptions.baudrate = USART_BAUD;
    usartOptions.charlength = USART_BITS;
    usartOptions.paritytype = USART_NO_PARITY;
    usartOptions.stopbits = USART_1_STOPBIT;
    usartOptions.channelmode = USART_NORMAL_CHMODE;

    /* Initialize USART in RS232 mode */
    error = usart_linit(usart, &usartOptions, CPUHZ);

    if (error != USART_OK) {
        pioc->odsr = AVR32_PIO_P8_MASK|AVR32_PIO_P9_MASK;
        for (;;);
    }

    printf("AVR32113: available demos:\r\n");
    printf("  SW2 - segmentation on\r\n");
    printf("        paging       on\r\n");
    printf("        exception example\r\n\n");
    printf("  SW1 - segmentation on\r\n");
    printf("        paging       on\r\n\n");
    printf("  SW0 - segmentation on\r\n");
    printf("        paging       off\r\n\n");

    unsigned int buttontimer = 0;

    for (;;) {
        /* SW2 - Page miss example
         * SW1 - Segment translation on, page translation on
         * SW0 - Segment translation on, page translation off (default)
         */
        if ((piob->pdsr & AVR32_PIO_P2_MASK) == 0 &&
                buttontimer == 0) {
            pioc->odsr = AVR32_PIO_P2_MASK;
            buttontimer = DELAY_TIMEOUT;

            int retval = MMU_OK;

            retval = mmuex_exceptions();

            if (retval == MMU_OK) {
                pioc->odsr = AVR32_PIO_P10_MASK|AVR32_PIO_P11_MASK;
            } else {
                pioc->odsr = AVR32_PIO_P8_MASK|AVR32_PIO_P9_MASK;
            }
        }
        else if ((piob->pdsr & AVR32_PIO_P1_MASK) == 0 &&
                buttontimer == 0) {
            pioc->odsr = AVR32_PIO_P1_MASK;
            buttontimer = DELAY_TIMEOUT;

            int retval = MMU_OK;

            retval = mmuex_segon_pageon();

            if (retval == MMU_OK) {
                pioc->odsr = AVR32_PIO_P10_MASK|AVR32_PIO_P11_MASK;
            } else {
                pioc->odsr = AVR32_PIO_P8_MASK|AVR32_PIO_P9_MASK;
            }
        }
        else if ((piob->pdsr & AVR32_PIO_P0_MASK) == 0 &&
                buttontimer == 0) {
            pioc->odsr = AVR32_PIO_P0_MASK;
            buttontimer = DELAY_TIMEOUT;

            int retval = MMU_OK;

            retval = mmuex_segon_pageoff();

            if (retval == MMU_OK) {
                pioc->odsr = AVR32_PIO_P10_MASK|AVR32_PIO_P11_MASK;
            } else {
                pioc->odsr = AVR32_PIO_P8_MASK|AVR32_PIO_P9_MASK;
            }
        }

        if (buttontimer > 0) {
            --buttontimer;
        }
    }

    return 0;
}

---