我是beaglebone和linux的新手,所以对于一个项目,im必须通过使用地址来控制BBB上的用户led,并且通过确保所有gpio端口都能够通过它来设置功能,以供将来使用。但是当我运行它来打开和关闭用户leds时,我得到了一个分段故障,我不知道为什么或者我需要做什么来解决这个问题。我需要包括什么,或者我正在做的事情是不允许的,如果是这样,我应该做什么?
#include <string.h>
#include <stdint.h>
#include <stdio.h>
typedef struct {
volatile uint32_t REVISION; //Address offset: 0x00
volatile uint32_t rangeA[3]; //Address offset: 0x04-0x0C
volatile uint32_t SYSCONFIG; //Address offset: 0x10
volatile uint32_t rangeB[3]; //Address offset: 0x14-0x1C
volatile uint32_t EOI; //Address offset: 0x20
volatile uint32_t IRQSTATUS_RAW_0; //Address offset: 0x24
volatile uint32_t IRQSTATUS_RAW_1; //Address offset: 0x28
volatile uint32_t IRQSTATUS_0; //Address offset: 0x2C
volatile uint32_t IRQSTATUS_1; //Address offset: 0x30
volatile uint32_t IRQSTATUS_SET_0; //Address offset: 0x34
volatile uint32_t IRQSTATUS_SET_1; //Address offset: 0x38
volatile uint32_t IRQSTATUS_CLR_0; //Address offset: 0x3C
volatile uint32_t IRQSTATUS_CLR_1; //Address offset: 0x40
volatile uint32_t IRQWAKEN_0 ; //Address offset: 0x44
volatile uint32_t IRQWAKEN_1; //Address offset: 0x48
volatile uint32_t rangeC[26]; //Address offset: 0x4C-0x110
volatile uint32_t SYSSTATUS; //Address offset: 0x114
volatile uint32_t rangeD[6]; //Address offset: 0x118-0x12C
volatile uint32_t CTRL; //Address offset: 0x130
volatile uint32_t OE; //Address offset: 0x134
volatile uint32_t DATAIN; //Address offset: 0x138
volatile uint32_t DATAOUT; //Address offset: 0x13C
volatile uint32_t LEVELDETECT0; //Address offset: 0x140
volatile uint32_t LEVELDETECT1; //Address offset: 0x144
volatile uint32_t RISINGDETEDT; //Address offset: 0x148
volatile uint32_t FALLINGDETECT; //Address offset: 0x14C
volatile uint32_t DEBOUNCENABLE; //Address offset: 0x150
volatile uint32_t DEBOUNCINGTIME; //Address offset: 0x154
volatile uint32_t rangeE[14]; //Address offset: 0x158-0x18C
volatile uint32_t CLEARDATAOUT; //Address offset: 0x190
volatile uint32_t SETDATAOUT; //Address offset: 0x194
} GPIO_TypeDef;
#define GPIO0 ((GPIO_TypeDef *) 0x44E07000)
#define GPIO1 ((GPIO_TypeDef *) 0x4804C000)
#define GPIO2 ((GPIO_TypeDef *) 0x481AC000)
#define GPIO3 ((GPIO_TypeDef *) 0x481AE000)
int main() //testing if this would work
{
GPIO1->OE &= ~(1UL<<21); // set bits to output eneble
while(1)
{
GPIO1->DATAOUT |= 1UL<<21;
int delay = 0;
while(delay < 15000) // just really quick crappy delay
delay++;
GPIO1->DATAOUT &= ~(1UL<<21);
printf("Blink!!\n"); //test to see if it works
}
return 0;
}
发布于 2019-03-21 06:50:03
您分配的地址似乎是物理地址或总线地址;您的程序将使用虚拟地址或程序地址运行。您机器上的内核构建转换页,因此您的程序可以保持内核可以动态分配的内存地址的规范化视图。
您需要(使用mmap())将寄存器的设备空间映射到您的程序中,并将您的结构指定为指向它们。
你应该会得到类似下面这样的代码:
GPIO_TypeDef *g0, *g1, ... ;
...
g0 = mmap(0, sizeof *g0,..., fd, 0);
...
g0->DataOut = 3;
...
ps:从风格上讲,前缀_TypeDef违背了typedef机制的目的,该机制的目的是生成有意义的名称和自记录程序。_t的惯用只是稍微好一点,因为它不会浪费太多的击键次数。请记住,有些程序员是视觉受损的,每次遇到这种情况时,他们都必须听一个辅助设备说“下划线大写T y p e大写D e f”!
https://stackoverflow.com/questions/55268146
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