为什么编译的时候还会出现如下问题:
337: error: implicit declaration of function ‘set_external_irq’
337: error: ‘EXT_LOWLEVEL’ undeclared (first use in this function)
337: error: (Each undeclared identifier is reported only once
337: error: for each function it appears in.)
337: error: ‘GPIO_PULLUP_DIS’ undeclared (first use in this function)
338: error: ‘SA_SHIRQ’ undeclared (first use in this function)
338: warning: passing argument 2 of ‘request_irq’ from incompatible pointer type