pvbemu/src/core/vue.c

#define VUEAPI
#include <vue.h>



/*****************************************************************************
 *                                 Constants                                 *
 *****************************************************************************/

/* Memory access type sizes */
static const int TYPE_SIZES[] = { 1, 1, 2, 2, 4 };



/*****************************************************************************
 *                            Component Includes                             *
 *****************************************************************************/

#include "bus.c"



/*****************************************************************************
 *                             Library Functions                             *
 *****************************************************************************/

/* Prepare an emulation state context for use */
void vueInitialize(VUE *vue) {
    vue->rom  = NULL;
    vue->sram = NULL;
}

/* Read bytes from the CPU bus */
vbool vueRead(VUE *vue, uint32_t address, uint8_t *dest, uint32_t length) {
    uint32_t count; /* Bytes to read in one iteration */

    /* Error checking */
    if (vue == NULL || dest == NULL)
        return VUE_FALSE;

    /* Perform the operation */
    for (; length > 0; address += count, length -= count, dest += count) {

        /* Determine the maximum number of bytes to process at once */
        count = 0x01000000 - (address & 0x00FFFFFF);
        if (count > length)
            count = length;

        /* Process by component */
        switch (address >> 24 & 7) {
            case 1: /* Fallthrough */ /* VSU (write-only) */
            case 3: /* Fallthrough */ /* Unmapped */
            case 4: /* Cartridge expansion (not supported) */
                busReadBytes(NULL     , dest, address, 0             , count);
                break;
            case 5: /* System WRAM */
                busReadBytes(vue->wram, dest, address, 0x10000       , count);
                break;
            case 6: /* Cartridge RAM */
                busReadBytes(vue->sram, dest, address, vue->sram_size, count);
                break;
            case 7: /* Cartridge ROM */
                busReadBytes(vue->rom , dest, address, vue->rom_size , count);
                break;
        }

    };
    return VUE_TRUE;
}

/* Specify a new ROM buffer */
vbool vueSetROM(VUE *vue, uint8_t *rom, uint32_t size) {

    /* Error checking */
    if (
        vue == NULL ||
        rom == NULL ||
        size < 1024 || size > 0x01000000 ||
        (size & (size - 1)) != 0
    ) return VUE_FALSE;

    /* Accept the new ROM buffer */
    vue->rom      = rom;
    vue->rom_size = size;
    return VUE_TRUE;
}

/* Write bytes to the CPU bus */
vbool vueWrite(VUE *vue, uint32_t address, uint8_t *src, uint32_t length) {
    uint32_t count; /* Bytes to write in one iteration */

    /* Error checking */
    if (vue == NULL || src == NULL)
        return VUE_FALSE;

    /* Perform the operation */
    for (; length > 0; address += count, length -= count, src += count) {

        /* Determine the maximum number of bytes to process at once */
        count = 0x01000000 - (address & 0x00FFFFFF);
        if (count > length)
            count = length;

        /* Process by component */
        switch (address >> 24 & 7) {
            case 5: /* System WRAM */
                busWriteBytes(vue->wram, src, address, 0x10000       , count);
                break;
            case 6: /* Cartridge RAM */
                busWriteBytes(vue->sram, src, address, vue->sram_size, count);
                break;
            case 7: /* Cartridge ROM */
                busWriteBytes(vue->rom , src, address, vue->rom_size , count);
                break;
        }

    };
    return VUE_TRUE;
}