install mysql service on centos 7

install

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$ sudo wget https://dev.mysql.com/get/mysql57-community-release-el7-9.noarch.rpm
$ sudo md5sum mysql57-community-release-el7-9.noarch.rpm
$ sudo rpm -ivh mysql57-community-release-el7-9.noarch.rpm
$ sudo yum install mysql-server

emmmmm,虽然说STM32的东西很基本很基本了但是如果不做点记录的话好多坑都会忘记,所以还是弄个踩坑记录吧。

踩的StdPeriphLib的坑

USART_IT_IDLE

USART的中断类型除了RXNE/TXE之外还有一个经常用到的是IDLE,但是st的官方库函数在中断处理函数中处理IDLE时有个bug:进IDLE后,必须要读取SR,DR寄存器后再执行功能代码,不然会一直进IRQHandler(死循环)。

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#ifdef __cplusplus
extern "C"
{
#endif //__cplusplus
void USART2_IRQHandler()
{
	uint8_t tsr;
	uint8_t tdr;
	if(USART_GetITStatus(USART2,USART_IT_IDLE)==SET)
	{
		tsr=USART2->SR;
		tdr=USART2->DR;
		//TODO:Meow
		USART_ClearFlag(USART2,USART_IT_IDLE);
	}
}
#ifdef __cplusplus
}
#endif //__cplusplus

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