好哦，前面分析到了arch_early_init

 1 void arch_early_init(void) {
 2     /* turn off the cache */
 3     arch_disable_cache(UCACHE);//关闭cache，不想细看了
 4 #if WITH_DEV_CACHE_PL310  //如果是PL310则关闭
 5     pl310_set_enable(false);
 6 #endif
 7 
 8     arm_basic_setup();//arm 基本设置
 9 
10 #if WITH_SMP && ARM_CPU_CORTEX_A9//如果是A9且SMP
11     /* enable snoop control */
12     addr_t scu_base = arm_read_cbar();
13     *REG32(scu_base) |= (1<<0); /* enable SCU */
14 #endif
15 
16 #if ARCH_HAS_MMU//如果有MMU
17     arm_mmu_early_init();
18 
19     platform_init_mmu_mappings();
20 #endif
21 
22     /* turn the cache back on */
23 #if WITH_DEV_CACHE_PL310//如果CACHE 310,则打开
24     pl310_set_enable(true);
25 #endif
26     arch_enable_cache(UCACHE);
27 }

 

void arch_early_init(void) {    /* turn off the cache */    arch_disable_cache(UCACHE);#if WITH_DEV_CACHE_PL310    pl310_set_enable(false);#endif
    arm_basic_setup();
#if WITH_SMP && ARM_CPU_CORTEX_A9    /* enable snoop control */    addr_t scu_base = arm_read_cbar();    *REG32(scu_base) |= (1<<0); /* enable SCU */#endif
#if ARCH_HAS_MMU    arm_mmu_early_init();
    platform_init_mmu_mappings();#endif
    /* turn the cache back on */#if WITH_DEV_CACHE_PL310    pl310_set_enable(true);#endif    arch_enable_cache(UCACHE);}