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感谢回复。
是u-boot刚上电的时候的底层初始化代码。我个人觉得原代码是写错了,确切的说,是bug。
当然正如你说的,一直也没出什么问题,所以大家都忽略了。
贴一下start.s的部分代码:- /*
- * the actual reset code
- */
- reset:
- /*
- * set the cpu to SVC32 mode
- */
- mrs r0,cpsr
- bic r0,r0,#0x1f
- orr r0,r0,#0xd3
- msr cpsr,r0
- /* turn off the watchdog */
- #if defined(CONFIG_S3C2400)
- # define pWTCON 0x15300000
- # define INTMSK 0x14400008 /* Interupt-Controller base addresses */
- # define CLKDIVN 0x14800014 /* clock divisor register */
- #elif defined(CONFIG_S3C2410)
- # define pWTCON 0x53000000
- # define INTMSK 0x4A000008 /* Interupt-Controller base addresses */
- # define INTSUBMSK 0x4A00001C
- # define CLKDIVN 0x4C000014 /* clock divisor register */
- #endif
- #if defined(CONFIG_S3C2400) || defined(CONFIG_S3C2410)
- ldr r0, =pWTCON
- mov r1, #0x0
- str r1, [r0]
- /*
- * mask all IRQs by setting all bits in the INTMR - default
- */
- mov r1, #0xffffffff
- ldr r0, =INTMSK
- str r1, [r0]
- # if defined(CONFIG_S3C2410)
- ldr r1, =0x3ff
- ldr r0, =INTSUBMSK
- str r1, [r0]
- # endif
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