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本帖最后由 ptostrike 于 2013-05-25 18:59 编辑
看到TQ2440的u-boot有以下代码:- int board_init (void)
- {
- S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
- /* set up the I/O ports */
- gpio->GPACON = 0x007FFFFF;
- gpio->GPBCON = 0x00055555;
- gpio->GPBUP = 0x000007FF;
- gpio->GPCCON = 0xAAAAAAAA;
- gpio->GPCUP = 0x0000FFFF;
- gpio->GPDCON = 0xAAAAAAAA;
- gpio->GPDUP = 0x0000FFFF;
- gpio->GPECON = 0xAAAAAAAA;
- gpio->GPEUP = 0x0000FFFF;
- gpio->GPFCON = 0x000055AA;
- gpio->GPFUP = 0x000000FF;
- gpio->GPGCON = 0xFF94FFBA;
- gpio->GPGUP = 0x0000FFEF;
- gpio->GPGDAT = gpio->GPGDAT & ((~(1<<4)) | (1<<4)) ;
- gpio->GPHCON = 0x002AFAAA;
- gpio->GPHUP = 0x000007FF;
- gpio->GPJCON = 0x02aaaaaa;
- gpio->GPJUP = 0x00001fff;
- // S3C24X0_I2S * const i2s = S3C24X0_GetBase_I2S(); //HJ_add 灞忚斀IIS,
- // i2s->IISCON = 0x00; //HJ_add 灞忚斀IIS,
- /* arch number of TQ2440-Board */
- gd->bd->bi_arch_number = MACH_TYPE_S3C2440;
- /* adress of boot parameters */
- gd->bd->bi_boot_params = 0x30000100;
- icache_enable();
- dcache_enable();
- return 0;
- }
- /* It makes no sense to use the dcache if the MMU is not enabled */
- void dcache_enable (void)
- {
- ulong reg;
- reg = read_p15_c1 ();
- cp_delay ();
- write_p15_c1 (reg | C1_DC);
- }
复制代码 调用board_init函数之前还没有启动MMU,请问各位大侠,这时候怎么就能就使能Dcache了啊? |
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