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S3C2410A的MMU初始化只需要调用通用的arm920 MMU初始化函数：
static inline void arm920_setup(void)
{
unsigned long ttb = MMU_TABLE_BASE;
__asm__(
/* Invalidate caches */
"mov r0, #0\n"
"mcr p15, 0, r0, c7, c7, 0\n" /* invalidate I,D caches on v4 */
"mcr p15, 0, r0, c7, c10, 4\n" /* drain write buffer on v4 */
"mcr p15, 0, r0, c8, c7, 0\n" /* invalidate I,D TLBs on v4 */
/* Load page table pointer */
"mov r4, %0\n"
"mcr p15, 0, r4, c2, c0, 0\n" /* load page table pointer */
/* Write domain id (cp15_r3) */
"mvn r0, #0\n" /* Domains 0, 1 = client */
"mcr p15, 0, r0, c3, c0, 0\n" /* load domain access register */
/* Set control register v4 */
"mrc p15, 0, r0, c1, c0, 0\n" /* get control register v4 */
/* Clear out 'unwanted' bits (then put them in if we need them) */
/* .RVI ..RS B... .CAM */
"bic r0, r0, #0x3000\n" /* ..11 .... .... .... */
"bic r0, r0, #0x0300\n" /* .... ..11 .... .... */
"bic r0, r0, #0x0087\n" /* .... .... 1... .111 */
/* Turn on what we want */
/* Fault checking enabled */
"orr r0, r0, #0x0002\n" /* .... .... .... ..1. */
#ifdef CONFIG_CPU_D_CACHE_ON
"orr r0, r0, #0x0004\n" /* .... .... .... .1.. */
#endif
#ifdef CONFIG_CPU_I_CACHE_ON
"orr r0, r0, #0x1000\n" /* ...1 .... .... .... */
#endif
/* MMU enabled */
"orr r0, r0, #0x0001\n" /* .... .... .... ...1 */
"mcr p15, 0, r0, c1, c0, 0\n" /* write control register */
: /* no outputs */
: "r" (ttb) );
} |
STEP4设置堆栈；STEP5进行mtd设备的初始化，记录MTD分区信息；STEP6设置私有数据；STEP7初始化内建命令。
STEP8启动一个SHELL，等待用户输出命令并进行相应处理。在SHELL退出的情况下，启动操作系统：
#define DEFAULT_BOOT_DELAY 0x30000000
void boot_or_vivi(void)
{
char c;
int ret;
ulong boot_delay;
boot_delay = get_param_value("boot_delay", &ret);
if (ret) boot_delay = DEFAULT_BOOT_DELAY;
/* If a value of boot_delay is zero,
* unconditionally call vivi shell */
if (boot_delay == 0) vivi_shell();
/*
* wait for a keystroke (or a button press if you want.)
*/
printk("Press Return to start the LINUX now, any other key for vivi\n");
c = awaitkey(boot_delay, NULL);
if (((c != '\r') && (c != '\n') && (c != '\0'))) {
printk("type \"help\" for help.\n");
vivi_shell();
}
run_autoboot();
return;
} |
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