clem_util.h

static uint8_t g_hex_to_decimal[256] = {
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x00-0x07 */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x08-0x0f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x10-0x17 */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x18-0x1f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x20-0x27 */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x28-0x2f */
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 0x30-0x37 */
    0x08, 0x09, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x38-0x3f */
    0xff, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0xff, /* 0x40-0x4f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x48-0x4f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x50-0x5f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x58-0x5f */
    0xff, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0xff, /* 0x60-0x6f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x68-0x6f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x70-0x7f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x78-0x7f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x80-0x8f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x88-0x8f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x90-0x9f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x98-0x9f */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xa0-0xaf */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xa8-0xaf */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xb0-0xbf */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xb8-0xbf */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xc0-0xcf */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xc8-0xcf */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xd0-0xdf */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xd8-0xdf */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xe0-0xef */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xe8-0xef */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xf0-0xff */
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff  /* 0xf8-0xff */
};

static char g_decimal_to_hex[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
                                    '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};

/**
 * @brief Returns a pointer to the memory bank contents and if its a mega2 bank
 *
 * NOTE: the mega2 flag is only changed if the bank is a mega2 bank (and left
 * unchanged if not)
 *
 * @param clem
 * @param bank
 * @param mega2
 * @return uint8_t*
 */
static inline uint8_t *_clem_get_memory_bank(ClemensMachine *clem, uint8_t bank, bool *mega2) {
    if (bank == 0xe0 || bank == 0xe1) {
        *mega2 = true;
        return clem->mem.mega2_bank_map[bank & 0x1];
    }
    return clem->mem.fpi_bank_map[bank];
}

static inline uint32_t _clem_calc_cycles_diff(uint32_t cycles_a, uint32_t cycles_b) {
    uint32_t diff = cycles_b - cycles_a;
    if (cycles_b > cycles_a) {
        return cycles_b - cycles_a;
    } else {
        return cycles_b + (UINT32_MAX - cycles_a) + 1;
    }
}

static inline unsigned clem_util_timer_decrement(unsigned timer_cnt, unsigned dt) {
    return (timer_cnt - dt < timer_cnt) ? (timer_cnt - dt) : 0;
}

static inline unsigned clem_util_timer_increment(unsigned timer_cnt, unsigned timer_max,
                                                 unsigned dt) {
    if (timer_cnt + dt > timer_cnt) {
        timer_cnt += dt;
    } else {
        timer_cnt = UINT32_MAX;
    }
    if (timer_cnt > timer_max) {
        timer_cnt = timer_max;
    }
    return timer_cnt;
}

static bool _clem_util_hex_value(uint32_t *value, const char *start, const char *end) {
    uint8_t hex;
    while (start != end) {
        *value <<= 4;
        hex = *start;
        if (hex == 0xff)
            return false;
        *value |= g_hex_to_decimal[hex];
        ++start;
    }
    return true;
}