Assembly 使用ARM组件闪烁覆盆子pi LED
我在尝试将LED连接到raspberry pi上的gpio引脚18时遇到问题。我已经用C测试了我的设置，并确认这不是问题所在，但我的汇编代码才是问题所在 这是我目前掌握的代码：Assembly 使用ARM组件闪烁覆盆子pi LED,assembly,raspberry-pi,arm,Assembly,Raspberry Pi,Arm,我在尝试将LED连接到raspberry pi上的gpio引脚18时遇到问题。我已经用C测试了我的设置，并确认这不是问题所在，但我的汇编代码才是问题所在 这是我目前掌握的代码： .global main main: SUB SP, SP, #16 @ Create 16 bytes storage LDR R0, .addr_file @ get GPIO Controller addr LDR R1, .flags @ se
.global main
main:
SUB SP, SP, #16 @ Create 16 bytes storage
LDR R0, .addr_file @ get GPIO Controller addr
LDR R1, .flags @ set flag permissions
BL open @ call to get file handle
STR R0, [SP, #12] @ File handle number
LDR R3, [SP, #12] @ Get File handle
STR R3, [SP, #0] @ Store file handle on top stack
LDR R3, .gpiobase @ get GPIO_Base address
STR R3, [SP, #4] @ store on SP+4
MOV R0, #0 @ R0=0
MOV R1, #4096 @ R1=page
MOV R2, #3 @ R2=3
MOV R3, #1 @ R3=1 (stdouts)
BL mmap @ call libc fct for mmap
STR R0, [SP, #16] @ store virtual mem addr
LDR R3, [SP, #16] @ get virtual mem addr
fctsel:
ADD R3, R3, #4 @ add 4 for block 1 (GPFSEL1)
LDR R2, [SP, #16] @ get virtual mem addr
ADD R2, R2, #16 @ add 4 for block 1 (GPFSEL1)
LDR R2, [R2, #0] @ load R2 with value at R2
BIC R2, R2, #0b111<<24 @ Bitwise clear of three bits
STR R2, [R3, #0] @ Store result in Register [set input]
LDR R3, [SP, #16] @ Get virtual mem address
ADD R3, R3, #4 @ Add 4 for block 1 (GPFSEL1)
LDR R2, [SP, #16] @ Get virtual mem addr
ADD R2, R2, #4 @ add 4 for block 1 (GPFSEL1)
LDR R2, [R2, #0] @ Load R2 with value at R2
ORR R2, R2, #1<<24 @ Set bit....
STR R2, [R3, #0] @ ...and make output
on:
LDR R3, [SP, #16] @ get virt mem addr
MOV R4, #1 @ get 1
MOV R2, R4, LSL#18 @ Shift by pin number
STR R2, [R3, #0] @ write to memory
LDR R0, [SP, #12] @ get file handle
BL close @ close file
ADD SP, SP, #16 @ restore SP
MOV R7, #1
SWI 0
.addr_file: .word .file
.flags: .word 1576962
@.gpiobase: .word 0x20200000 @ GPIO_Base for Pi 1
.gpiobase: .word 0x3F200000 @ GPIO_Base for Pi 2
.data
.file: .ascii "/dev/mem\000"
我设法让它与GPIO 47引脚工作。然而，当我将其更改为使用引脚18时，这就是我遇到问题的地方。提前感谢您的帮助，非常感谢 查看BCM2835文档-Broadcom BCM2835 ARM外围设备 您的代码似乎基于Raspberry Pi，汇编语言，Bruce Smith 我不明白为什么我们要清除3位，因为文件上说是为输入设置的 ***我确认它在我的RPi 2 B上工作，针脚上有3+伏电压 目标引脚=18 设置GPIO函数： 26-24 FSEL18 FSEL18-功能选择18 R/W 0 在GPIO备用功能中选择寄存器1 所以：0x 7E20 0004 GPFSEL1 GPIO函数选择1 32 R/W |偏移量0x4
init_output: // init for OUTPUT
ldr r3, [sp, #8] // virt GPIO base
add r3, r3, #0x4 // offset to GPFSEL1
ldr r2, [r3] // get contents of GPFSEL1
orr r2, r2, #0b001<<18 // set 3 bits re FSEL18 output
str r2, [r3] // store set bits at GPFSEL1
set_pin:
ldr r3, [sp, #8] // virt GPIO base
add r3, r3, #0x1C // GPSET0
ldr r2, [r3] // get content of GPSET0
orr r2, r2, #1<<18 // set PIN 18
str r2,[r3] // set PIN 18 @ GPSET0
clear_pin:
ldr r3, [sp, #8] // virt GPIO base
add r3, r3, #0x28 // GPCLR0
ldr r2, [r3] // get content of GPCLR0
orr r2, r2, #1<<18 // set PIN 18
str r2,[r3] // set PIN 18 @ GPCLR0
查看BCM2835文档-Broadcom BCM2835 ARM外围设备 您的代码似乎基于Raspberry Pi，汇编语言，Bruce Smith 我不明白为什么我们要清除3位，因为文件上说是为输入设置的 ***我确认它在我的RPi 2 B上工作，针脚上有3+伏电压 目标引脚=18 设置GPIO函数： 26-24 FSEL18 FSEL18-功能选择18 R/W 0 在GPIO备用功能中选择寄存器1 所以：0x 7E20 0004 GPFSEL1 GPIO函数选择1 32 R/W |偏移量0x4
init_output: // init for OUTPUT
ldr r3, [sp, #8] // virt GPIO base
add r3, r3, #0x4 // offset to GPFSEL1
ldr r2, [r3] // get contents of GPFSEL1
orr r2, r2, #0b001<<18 // set 3 bits re FSEL18 output
str r2, [r3] // store set bits at GPFSEL1
set_pin:
ldr r3, [sp, #8] // virt GPIO base
add r3, r3, #0x1C // GPSET0
ldr r2, [r3] // get content of GPSET0
orr r2, r2, #1<<18 // set PIN 18
str r2,[r3] // set PIN 18 @ GPSET0
clear_pin:
ldr r3, [sp, #8] // virt GPIO base
add r3, r3, #0x28 // GPCLR0
ldr r2, [r3] // get content of GPCLR0
orr r2, r2, #1<<18 // set PIN 18
str r2,[r3] // set PIN 18 @ GPCLR0
这里有一个修改后的备选答案，用C 由InfinitelyManic澄清的解决方案在Pi-0运行拉伸上运行良好。set操作在运行Jessie K 4.9.35或Openelec 8.0.4=Kodi 17.3内核4.9.30的Pi-1B上运行良好，但clear操作清除了pin，但挂起了系统 我使用合并自fdbdcbc和InfinitelyManic的汇编代码作为C过程的原型来做同样的事情。我的希望是C版本可能更易于移植。它使用上述技术对管脚进行直接内存控制，而不使用wiringPi或其他库，这是我无法加载到Openelec上的。在调试中，我发现设置SET/CLR寄存器只需要写入表示要设置/CLR的管脚的一位；复制和重写寄存器导致系统挂起CLR 我已经对一些代码进行了大量的注释，并使用标准的C包含定义将其从汇编程序反向工程到C 下面的代码适用于运行Stretch的Pi-0版本代码920093和运行Jessie或Openelec的Pi-1B版本代码000e
/* gblink.c
Procedures to set and clear Raspberry Pi GPIO pins through direct
memory access rather than through major libraries (such as wiringPi).
Advantages: speed and portability (requiring no special libraries).
Disadvantage: limited capability, long-term maintenance, flexibility.
If running on Pi-2, change ref to gpioBASE to gpioBASE2 in mmap call
Don't know what to use if Pi-3
With testing program.
Compile as
gcc -o gblink gblink.c
run as
sudo gblink <pin number>
Written by hdtodd, 12 Dec 2017, based on Stack Overflow ARM
assembler examples by InfinitelyManic on 10 Mar 2017:
https://stackoverflow.com/questions/42702056/
flash-raspberry-pi-led-using-arm-assembly
Corrected 23 Dec 2017 to write rather than rewrite SET/CLR registers.
See also:
https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <ctype.h>
#include <strings.h>
#include <time.h>
#include <signal.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#define memFile "/dev/mem" // memory device for mapping
#define memFlags O_RDWR | O_SYNC // flags for opening mem
#define baseGPIO 0x20200000 // GPIO_Base address for Pi 1
#define baseGPIO2 0x3F200000 // GPIO_Base address for Pi 2
#define pinMAX 32 // max # of GPIO pins we'll support (for simplicity)
#define pinsPerSEL 10 // 3 bits/field, 10 fields/register in GFSELn's
#define outMask 0b111 // 3-bit field mask to clear GFSEL register
#define outEnable 0b001 // 3-bit pattern for GFSEL registers to enable output
#define offsetSET 7 // word-address offset to GPSET0 word to set pin (0x1c bytes)
#define offsetCLR 10 // word-address offset to GPCLR0 word to clear pin (0x28 bytes)
typedef enum {false=0, true=~0} boolean;
static uint32_t *vAddrGPIO; // mapped address to physical GPIO register base
int memFH; // file handle for /dev/mem
boolean alreadyMapped = false;
boolean keepBlinking = true;
struct sigaction act; // catch CNTL-C to terminate cleanly
uint32_t gpFSEL, fSELn; // offset to GPIO Function SELect register for this
// pin & Field SEL loc in that register for this pin
boolean gblinkDebug = false; // enables printing debug information
// cntlCHandler() triggers end of main loop if a ^C is received on controlling terminal
void cntlCHandler(int sigType) {
keepBlinking = false;
};
// enableGPIO maps memory to GPIO registers and sets pin 'pinNum' to be an output pin
boolean enableGPIO(int pinNum) {
if (pinNum < 0 || pinNum > pinMAX-1) {
printf("[enableGPIO:] Requested pin # %d out of range 0 to %d\n", pinNum, pinMAX-1);
return false;
};
// if we haven't already done it, map GPIO registers to our memory space
if ( !alreadyMapped ) {
if ( (memFH = open(memFile,memFlags)) < 0) {
perror("[?enableGPIO:] Can't open '/dev/mem' file; exiting. Rerun as root?");
exit(EXIT_FAILURE);
}
vAddrGPIO = (uint32_t *)mmap(NULL,getpagesize(),PROT_WRITE|PROT_READ,MAP_SHARED,memFH,baseGPIO);
if (vAddrGPIO == MAP_FAILED) {
perror("[?enableGPIO:] Can't map to GPIO register addresses; exiting. Rerun as root?");
exit(EXIT_FAILURE);
};
alreadyMapped = true;
};
// locate the register and field for this pin and set it for output
if (gblinkDebug)
printf("[enableGPIO] Memory-mapped base address of GPIO register set is vAddrGPIO = %p\n", vAddrGPIO);
gpFSEL = pinNum/pinsPerSEL; // offset to register for this pin
fSELn = 3*(pinNum%pinsPerSEL); // location in register of 3-bit field for this pin
if (gblinkDebug) {
printf("[enableGPIO] GPIO pin mapped to GPFSEL%d and 3-bit FSEL field at bit %d in that register.\n", gpFSEL, fSELn);
printf("[enableGPIO] Will use gpioSEL register at %p\n", (vAddrGPIO+gpFSEL));
};
*(vAddrGPIO+gpFSEL) = ( *(vAddrGPIO+gpFSEL) & ~(outMask<<fSELn)) | (outEnable<<fSELn);
if (gblinkDebug)
printf("[enableGPIO] After setting, GPFSEL%d register contents = %x\n", gpFSEL, *(vAddrGPIO+gpFSEL));
return true;
};
// sets the pin voltage high (+5v)
boolean setOutput(int pinNum) {
if (pinNum < 0 || pinNum >= pinMAX) {
printf("[setOutput] Requested pin # %d is outside of allowed range 0 to %d\n", pinNum, pinMAX-1);
return false;
};
if (gblinkDebug)
printf("[setOutput] Writing to pin field %d at GPIO register address %p\n", pinNum, (vAddrGPIO+offsetSET));
*(vAddrGPIO+offsetSET) = 1<<pinNum; // write to "set" bit
return true;
};
// sets the pin voltage low (+0v)
boolean clrOutput(int pinNum) {
if (pinNum < 0 || pinNum >= pinMAX) {
printf("[clrOutput] Requested pin # %d is outside of allowed range 0 to %d\n", pinNum, pinMAX-1);
return false;
};
if (gblinkDebug)
printf("[clrOutput] Writing to pin field %d at GPIO register address %p\n", pinNum, (vAddrGPIO+offsetCLR));
*(vAddrGPIO+offsetCLR) = 1<<pinNum; // write to "clr" bit
return true;
};
void main(int argc, char *argv[]) {
int pinNum;
// validate arguments and/or provide help
if ( (argc < 2) || (strcasecmp(argv[1],"-h")==0) || !isdigit(argv[1][0]) ) {
printf("gblink: program to test direct memory control of GPIO pins by toggling pin voltage high<-->low\n");
printf(" usage: gblink [ pin number, >=0, <=%d ]\n", pinMAX-1);
printf(" where pin number is BCM2835 numbering system. Not GPIO or Pi!\n");
printf(" Install wiringPi and run 'gpio readall' to see pin map\n");
printf(" Debug with 'sudo GBLINK_DEBUG=1 gblink <pin number>'\n");
return;
};
// we need to run as root to open and map memory
if (geteuid() != 0) {
fprintf(stderr, "[?%s:] Must be run as root. Try 'sudo %s <pin number>'\n", argv[0], argv[0]);
exit(EXIT_FAILURE);
};
// do we want to provide debugging information along the way?
if (getenv("GBLINK_DEBUG") != NULL) {
printf("[gblink:] Debug mode enabled\n");
gblinkDebug = true;
};
// OK, ready to go. Catch ^C's to exit cleanly
act.sa_handler = cntlCHandler;
sigaction(SIGINT, &act, NULL);
// which pin are we working with?
pinNum = atoi(argv[1]);
if (gblinkDebug)
printf("[gblink:] Using GPIO pin %d\n", pinNum);
// enable that pin for output
if ( !enableGPIO(pinNum) ) {
perror("[gblink:] Can't enable GPIO output. ");
exit(EXIT_FAILURE);
};
// until we're told to stop, just keep blinking
while (keepBlinking) {
if (gblinkDebug) printf("[gblink:] Turning pin ON\n");
setOutput(pinNum);
sleep(2);
if (gblinkDebug) printf("[gblink:] Turning pin OFF\n");
clrOutput(pinNum);
sleep(5);
};
/* ^C terminate the loop above and drops into this cleanup code */
printf("[gblink:] CNTL-C halt. Clean up and exit.\n");
if (alreadyMapped) {
munmap(vAddrGPIO,getpagesize());
close(memFH);
};
return;
};
这里有一个修改后的备选答案，用C 由InfinitelyManic澄清的解决方案在Pi-0运行拉伸上运行良好。set操作在运行Jessie K 4.9.35或Openelec 8.0.4=Kodi 17.3内核4.9.30的Pi-1B上运行良好，但clear操作清除了pin，但挂起了系统 我使用合并自fdbdcbc和InfinitelyManic的汇编代码作为C过程的原型来做同样的事情。我的希望是C版本可能更易于移植。它使用上述技术对管脚进行直接内存控制，而不使用wiringPi或其他库，这是我无法加载到Openelec上的。在调试中，我发现设置SET/CLR寄存器只需要写入表示要设置/CLR的管脚的一位；复制和重写寄存器导致系统挂起CLR 我已经对一些代码进行了大量的注释，并使用标准的C包含定义将其从汇编程序反向工程到C 下面的代码适用于运行Stretch的Pi-0版本代码920093和运行Jessie或Openelec的Pi-1B版本代码000e
/* gblink.c
Procedures to set and clear Raspberry Pi GPIO pins through direct
memory access rather than through major libraries (such as wiringPi).
Advantages: speed and portability (requiring no special libraries).
Disadvantage: limited capability, long-term maintenance, flexibility.
If running on Pi-2, change ref to gpioBASE to gpioBASE2 in mmap call
Don't know what to use if Pi-3
With testing program.
Compile as
gcc -o gblink gblink.c
run as
sudo gblink <pin number>
Written by hdtodd, 12 Dec 2017, based on Stack Overflow ARM
assembler examples by InfinitelyManic on 10 Mar 2017:
https://stackoverflow.com/questions/42702056/
flash-raspberry-pi-led-using-arm-assembly
Corrected 23 Dec 2017 to write rather than rewrite SET/CLR registers.
See also:
https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <ctype.h>
#include <strings.h>
#include <time.h>
#include <signal.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#define memFile "/dev/mem" // memory device for mapping
#define memFlags O_RDWR | O_SYNC // flags for opening mem
#define baseGPIO 0x20200000 // GPIO_Base address for Pi 1
#define baseGPIO2 0x3F200000 // GPIO_Base address for Pi 2
#define pinMAX 32 // max # of GPIO pins we'll support (for simplicity)
#define pinsPerSEL 10 // 3 bits/field, 10 fields/register in GFSELn's
#define outMask 0b111 // 3-bit field mask to clear GFSEL register
#define outEnable 0b001 // 3-bit pattern for GFSEL registers to enable output
#define offsetSET 7 // word-address offset to GPSET0 word to set pin (0x1c bytes)
#define offsetCLR 10 // word-address offset to GPCLR0 word to clear pin (0x28 bytes)
typedef enum {false=0, true=~0} boolean;
static uint32_t *vAddrGPIO; // mapped address to physical GPIO register base
int memFH; // file handle for /dev/mem
boolean alreadyMapped = false;
boolean keepBlinking = true;
struct sigaction act; // catch CNTL-C to terminate cleanly
uint32_t gpFSEL, fSELn; // offset to GPIO Function SELect register for this
// pin & Field SEL loc in that register for this pin
boolean gblinkDebug = false; // enables printing debug information
// cntlCHandler() triggers end of main loop if a ^C is received on controlling terminal
void cntlCHandler(int sigType) {
keepBlinking = false;
};
// enableGPIO maps memory to GPIO registers and sets pin 'pinNum' to be an output pin
boolean enableGPIO(int pinNum) {
if (pinNum < 0 || pinNum > pinMAX-1) {
printf("[enableGPIO:] Requested pin # %d out of range 0 to %d\n", pinNum, pinMAX-1);
return false;
};
// if we haven't already done it, map GPIO registers to our memory space
if ( !alreadyMapped ) {
if ( (memFH = open(memFile,memFlags)) < 0) {
perror("[?enableGPIO:] Can't open '/dev/mem' file; exiting. Rerun as root?");
exit(EXIT_FAILURE);
}
vAddrGPIO = (uint32_t *)mmap(NULL,getpagesize(),PROT_WRITE|PROT_READ,MAP_SHARED,memFH,baseGPIO);
if (vAddrGPIO == MAP_FAILED) {
perror("[?enableGPIO:] Can't map to GPIO register addresses; exiting. Rerun as root?");
exit(EXIT_FAILURE);
};
alreadyMapped = true;
};
// locate the register and field for this pin and set it for output
if (gblinkDebug)
printf("[enableGPIO] Memory-mapped base address of GPIO register set is vAddrGPIO = %p\n", vAddrGPIO);
gpFSEL = pinNum/pinsPerSEL; // offset to register for this pin
fSELn = 3*(pinNum%pinsPerSEL); // location in register of 3-bit field for this pin
if (gblinkDebug) {
printf("[enableGPIO] GPIO pin mapped to GPFSEL%d and 3-bit FSEL field at bit %d in that register.\n", gpFSEL, fSELn);
printf("[enableGPIO] Will use gpioSEL register at %p\n", (vAddrGPIO+gpFSEL));
};
*(vAddrGPIO+gpFSEL) = ( *(vAddrGPIO+gpFSEL) & ~(outMask<<fSELn)) | (outEnable<<fSELn);
if (gblinkDebug)
printf("[enableGPIO] After setting, GPFSEL%d register contents = %x\n", gpFSEL, *(vAddrGPIO+gpFSEL));
return true;
};
// sets the pin voltage high (+5v)
boolean setOutput(int pinNum) {
if (pinNum < 0 || pinNum >= pinMAX) {
printf("[setOutput] Requested pin # %d is outside of allowed range 0 to %d\n", pinNum, pinMAX-1);
return false;
};
if (gblinkDebug)
printf("[setOutput] Writing to pin field %d at GPIO register address %p\n", pinNum, (vAddrGPIO+offsetSET));
*(vAddrGPIO+offsetSET) = 1<<pinNum; // write to "set" bit
return true;
};
// sets the pin voltage low (+0v)
boolean clrOutput(int pinNum) {
if (pinNum < 0 || pinNum >= pinMAX) {
printf("[clrOutput] Requested pin # %d is outside of allowed range 0 to %d\n", pinNum, pinMAX-1);
return false;
};
if (gblinkDebug)
printf("[clrOutput] Writing to pin field %d at GPIO register address %p\n", pinNum, (vAddrGPIO+offsetCLR));
*(vAddrGPIO+offsetCLR) = 1<<pinNum; // write to "clr" bit
return true;
};
void main(int argc, char *argv[]) {
int pinNum;
// validate arguments and/or provide help
if ( (argc < 2) || (strcasecmp(argv[1],"-h")==0) || !isdigit(argv[1][0]) ) {
printf("gblink: program to test direct memory control of GPIO pins by toggling pin voltage high<-->low\n");
printf(" usage: gblink [ pin number, >=0, <=%d ]\n", pinMAX-1);
printf(" where pin number is BCM2835 numbering system. Not GPIO or Pi!\n");
printf(" Install wiringPi and run 'gpio readall' to see pin map\n");
printf(" Debug with 'sudo GBLINK_DEBUG=1 gblink <pin number>'\n");
return;
};
// we need to run as root to open and map memory
if (geteuid() != 0) {
fprintf(stderr, "[?%s:] Must be run as root. Try 'sudo %s <pin number>'\n", argv[0], argv[0]);
exit(EXIT_FAILURE);
};
// do we want to provide debugging information along the way?
if (getenv("GBLINK_DEBUG") != NULL) {
printf("[gblink:] Debug mode enabled\n");
gblinkDebug = true;
};
// OK, ready to go. Catch ^C's to exit cleanly
act.sa_handler = cntlCHandler;
sigaction(SIGINT, &act, NULL);
// which pin are we working with?
pinNum = atoi(argv[1]);
if (gblinkDebug)
printf("[gblink:] Using GPIO pin %d\n", pinNum);
// enable that pin for output
if ( !enableGPIO(pinNum) ) {
perror("[gblink:] Can't enable GPIO output. ");
exit(EXIT_FAILURE);
};
// until we're told to stop, just keep blinking
while (keepBlinking) {
if (gblinkDebug) printf("[gblink:] Turning pin ON\n");
setOutput(pinNum);
sleep(2);
if (gblinkDebug) printf("[gblink:] Turning pin OFF\n");
clrOutput(pinNum);
sleep(5);
};
/* ^C terminate the loop above and drops into this cleanup code */
printf("[gblink:] CNTL-C halt. Clean up and exit.\n");
if (alreadyMapped) {
munmap(vAddrGPIO,getpagesize());
close(memFH);
};
return;
};
我认为需要对上面的InfinitelyManic代码进行一点修改 在set_pin:/clear_pin:节中，而不是
// ldr r2, [r3] // get content of GPCLR0
// orr r2, r2, #1<<23 // set PIN 23 to 1 ==> set pin voltage to low
大量的实验导致了一种说法——复制和重写而不是仅仅写作——成为问题的根源。在运行Stretch的Pi-0、K 4.9.66+、运行Jessie的Pi-1B、K 4.9.35和运行Openelec 8.0.4 aka Kodi 17.3、K 4.9.30的Pi-1B上测试并验证了两个版本的代码。这两种形式的代码都在Pi-0上运行；复制和重写版本将Jessie和Openelec挂在Pi-1B上。我认为需要对上面的InfinitelyManic代码进行一点修改 在set_pin:/clear_pin:节中，而不是
// ldr r2, [r3] // get content of GPCLR0
// orr r2, r2, #1<<23 // set PIN 23 to 1 ==> set pin voltage to low
大量的实验导致了一种说法——复制和重写而不是仅仅写作——成为问题的根源。在运行Stretch的Pi-0、K 4.9.66+、运行Jessie的Pi-1B、K 4.9.35和运行Openelec 8.0.4 aka Kodi 17.3、K 4.9.30的Pi-1B上测试并验证了两个版本的代码。这两种形式的代码都在Pi-0上运行；复制和重写版本将Jessie和Openelec挂在Pi-1B上。忘了问你使用的是哪种覆盆子Pi。GPIO引脚布局很重要，它们都不一样。您是否使用存储/重新加载STR R0、[SP，16]/LDR R3、[SP，16]作为某种故意延迟？如果不是，那么未优化的编译器生成的代码就不是一个很好的例子。它在C语句之间溢出/重新加载到内存，仅支持在断点处停止时使用调试器修改C变量。普通代码应该只在寄存器中保存变量；ARM有16台，其中14台为通用型。无论如何，我认为您不需要将任何内容泄漏到内存中，因此唯一的存储应该是实际的MMIO写入。从仅链接回答：描述GPIO引脚，可能有用。忘了问您使用的是哪种覆盆子Pi。GPIO引脚布局很重要，它们都不一样。您是否使用存储/重新加载STR R0、[SP，16]/LDR R3、[SP，16]作为某种故意延迟？如果不是，那么未优化的编译器生成的代码就不是一个很好的例子。它在C语句之间溢出/重新加载到内存，仅支持在断点处停止时使用调试器修改C变量。普通代码应该只在寄存器中保存变量；ARM有16台，其中14台为通用型。无论如何，我认为你不需要把任何东西泄漏到内存中，所以唯一的存储应该是实际的MMIO写入。从一个只链接的答案：描述GPIO引脚，可能有用。谢谢你的帮助，我很感激！谢谢你的帮助，我很感激！为了更好地处理错误，可以使用perror而不是printf来解码errno。以非根用户身份运行时，可能会得到错误的文件句柄，因为memFH将是-1。当然，使用strace./a.out会提供更多信息，这是
在简单的工具中编写完整的错误检测的替代方法，如：Pexit；不会退出进程，但会编译。这与编写void&exit是一样的，因为exit是一个库函数。我想你想要离开；你应该从墙上得到一个关于一个没有效果的声明的警告，因为你没有把它作废。谢谢，彼得。这两个建议结合在一起，我找到了挂起的来源。为了更好地处理错误，您可以使用perror而不是printf来解码errno。以非根用户身份运行时，可能会得到错误的文件句柄，因为memFH将是-1。当然，使用strace./a.out会给您提供更多信息，并且是在像这样的简单工具中编写完整错误检测的懒惰替代品：Pexit；不会退出进程，但会编译。这与编写void&exit是一样的，因为exit是一个库函数。我想你想要离开；你应该从墙上得到一个关于一个没有效果的声明的警告，因为你没有把它作废。谢谢，彼得。这两个建议结合在一起，我找到了挂起的来源。我认为ORRing为了设置/清除目标位不会设置/清除任何其他位。将1写入set或CLR寄存器中的任何位将分别设置相应的引脚高或低。我认为重写位是一种方法，复制SET或CLR寄存器，将要设置/CLR的管脚的位设置为1，然后重写寄存器，因为除了所需的位/管脚之外，您不会改变任何东西。这在Pi-0上似乎效果很好。但Pi-1B的接线方式似乎有点不同，重写CLR寄存器中的一些其他位似乎会影响BCM连接的其他硬件。我的设备是运行Debian的Pi 2型号B Rev 1.1；技术上是BCM2836。我认为当时没有BCM2836文档可用/发布。尽管如此，我的Pi并没有被锁定。干得好。我认为ORRing为了设置/清除目标位不会设置/清除任何其他位。将1写入set或CLR寄存器中的任何位将分别设置相应的引脚高或低。我认为重写位是一种方法，复制SET或CLR寄存器，将要设置/CLR的管脚的位设置为1，然后重写寄存器，因为除了所需的位/管脚之外，您不会改变任何东西。这在Pi-0上似乎效果很好。但Pi-1B的接线方式似乎有点不同，重写CLR寄存器中的一些其他位似乎会影响BCM连接的其他硬件。我的设备是运行Debian的Pi 2型号B Rev 1.1；技术上是BCM2836。我认为当时没有BCM2836文档可用/发布。尽管如此，我的Pi并没有被锁定。干得好。