I'm trying to figure out why netstat on my Mac OS X computer prints stuff like "got 4 twice".
For example:
$ netstat | head -15
Active Internet connections
Proto Recv-Q Send-Q Local Address Foreign Address (state)
[...]
tcp4 0 0 localhost.56892 localhost.26164 ESTABLISHED
got 4 twice
got 16 twice
got 1 twice
got 4 twice
got 4 twice
got 8 twice
The message is printed by netstat's inet.c, in the function protopr which basically does the following:
Calls sysctlbyname(3) using e.g. net.inet.tcp.pcblist_n to get a list of PCBs (I guess?)
Loops through the results, collecting pointers to various structs, whose type is called an xgn_kind
It sets a bit for each xgn_kind it has seen. If it sees any of them twice, it complains with the message "got %d twice".
I've cut out the relevant parts of the code:
void
protopr(uint32_t proto, /* for sysctl version we pass proto # */
char *name, int af)
{
/* ... */
if (sysctlbyname(mibvar, 0, &len, 0, 0) < 0) {
if (errno != ENOENT)
warn("sysctl: %s", mibvar);
return;
}
/* ... */
for (next = buf + ROUNDUP64(xig->xig_len);
next < buf + len;
next += ROUNDUP64(xgn->xgn_len))
{
/* ... */
if ((which & xgn->xgn_kind) == 0) {
which |= xgn->xgn_kind;
/* ... */
} else {
printf("got %d twice\n", xgn->xgn_kind);
}
/* ... */
}
My question is, finally:
Why is this happening? Is it faulty data coming back from sysctl? Is the loop above incorrect, i.e., can sysctl actually return several structs per kind?
Note that I'm running Mac OS X -- and the code is indeed a little bit different from FreeBSD's.
Related
This is going to be a bit abstract due to the specific ARM (LPCXpresso 1115R/303) Cortex M0 and the H6 bluetooth module, and with NXP software there are a ton of driver files that are linked so hopefully the code snip below will be enough to identify the problem.
I am creating a simple menu system through bluetooth. Everything works with communcation. I send the message from the board, it is visible on the phone, I respond and print the value in the console of the program. All are exactly what I want them to be. But this is what happens:
1) start debug session and resume
2) 1st menu sends to phone, correct.
3) Type response to phone and send, correct.
4) message appears in console exactly as entered from phone (Just the number 1 appears)
5) Have if loop that checks to see if Buffer value == '1';
6) must not == 1 because it never enters the loop.
7) reprints the value of the buffer, and it still equals 1.
The only hint I have is a warning that says "makes integer from pointer without a cast [-Wint-conversion]" on the assignment line as indicated below.
void ArmPeripheral() {
UARTCount = 0;
LPC_UART->IER = IER_THRE | IER_RLS; /* Disable RBR */
UARTSend( (uint8_t *)menu1, sizeof(menu1));
LPC_UART->IER = IER_THRE | IER_RLS | IER_RBR; /* Re-enable RBR */
while(1) {
if(UARTCount != 0){
printf("%s 1st print\n",UARTBuffer);
int bVal = UARTBuffer; // This is where the error occurs, tried uint8_t, did not work.
printf("%s This is bVal\n",bVal);
if(bVal == 1) { //have tried 1, '1', and "1" none work
printf("inside loop %s...\n",UARTBuffer);
printf("%s This is bVal\n",bVal);
LEDControl();
}
printf("%s second print\n",UARTBuffer);
UARTCount = 0;
}
}
}
enter image description here
Nevermind, it was just a simple pointer issue. UARTBuffer is a external volatile uint8_t in the UART.c file, and even though it is not defined as a pointer, it is pointing to a buffer somehow.
int bVal = *UARTBuffer;
if(bVal == '1') {
The above worked, but if anyone has any more in depth information that could explain why I would be interested in knowing. This is how I initialized the buffer:
extern volatile uint32_t UARTCount;
extern volatile uint8_t UARTBuffer[BUFSIZE];
I have been trying for the last few weeks to find out why this isn't working. I have tried reading all the documentation I could find on my PIC32 MCU (PIC32MX795F512L) and the XC32 compiler I am using (v1.34) but with no success as of yet.
I need a special constant value written to the physical boot flash address 0x1FC02FEC (Virtual address: 0x9FC02FEC). This constant is 0x3BDFED92.
I have managed to successfully do this on my main program (If I program my pic32 directly using Real ICE) by means of the following command line (Which I put in xc32-ld under "Additional options" under the Project Properties):
--fill=0x3bdfed92#0x9FC02FEC
I am then able to check (Inside my main program) if this address indeed does have the correct value stored inside it, and this works too. I use the following code for that:
if(*(int *)(0x9fc02fec) == 0x3bdfed92)
My problem is the following. I do not want my main program hex file to write the constant into that location. I want my bootloader hex file to do this and my main program must just be able to read that location and see if that constant is there. If I use the --fill command inside the xc32-ld of my bootloader program, it successfully writes the constant just like the main program did (I have tested this by running my bootloader program with the same --fill command in debug mode and checking the 0x1FC02FEC address for the constant). Problem is, when my bootloader reads in a new main program via the MicroSD, and then jumps to the new main program, everything doesn't work. Seems like, before it jumps to the new main program, something bad happens and everything crashes. Almost like writing a value to the 1FC02FEC location is a problem when the program jumps from boot loader to main program.
Is there a reason for this? I hope my explanation is ok, if not then please let me know and I will try reword it in a more understandable way.
I am using the example code provided by Microchip to do the bootloader using the MicroSD card. The following is the code:
int main(void)
{
volatile UINT i;
volatile BYTE led = 0;
// Setup configuration
(void)SYSTEMConfig(SYS_FREQ, SYS_CFG_WAIT_STATES | SYS_CFG_PCACHE);
InitLED();
TRISBbits.TRISB14 = 0;
LATBbits.LATB14 = 0;
ClrWdt();
// Create a startup delay to resolve trigger switch bouncing issues
unsigned char x;
WORD ms = 500;
DWORD dwCount = 25;
while(ms--)
{
ClrWdt();
x=4;
while(x--)
{
volatile DWORD _dcnt;
_dcnt = dwCount*((DWORD)(0.00001/(1.0/GetInstructionClock())/10));
while(_dcnt--)
{
#if defined(__C32__)
Nop();
Nop();
Nop();
#endif
}
}
}
if(!CheckTrigger() && ValidAppPresent())
{
// This means the switch is not pressed. Jump
// directly to the application
JumpToApp();
}
else if(CheckTrigger() && ValidAppPresent()){
if(MDD_MediaDetect()){
if(FSInit()){
myFile = FSfopen("image.hex","r");
if(myFile == NULL){
JumpToApp();
}
}
else{
JumpToApp();
}
}
else{
JumpToApp();
}
}
//Initialize the media
while (!MDD_MediaDetect())
{
// Waiting for media to be inserted.
BlinkLED();
}
// Initialize the File System
if(!FSInit())
{
//Indicate error and stay in while loop.
Error();
while(1);
}
myFile = FSfopen("image.hex","r");
if(myFile == NULL)// Make sure the file is present.
{
//Indicate error and stay in while loop.
Error();
while(1);
}
// Erase Flash (Block Erase the program Flash)
EraseFlash();
// Initialize the state-machine to read the records.
record.status = REC_NOT_FOUND;
while(1)
{
ClrWdt();
// For a faster read, read 512 bytes at a time and buffer it.
readBytes = FSfread((void *)&asciiBuffer[pointer],1,512,myFile);
if(readBytes == 0)
{
// Nothing to read. Come out of this loop
// break;
FSfclose(myFile);
// Something fishy. The hex file has ended abruptly, looks like there was no "end of hex record".
//Indicate error and stay in while loop.
Error();
while(1);
}
for(i = 0; i < (readBytes + pointer); i ++)
{
// This state machine seperates-out the valid hex records from the read 512 bytes.
switch(record.status)
{
case REC_FLASHED:
case REC_NOT_FOUND:
if(asciiBuffer[i] == ':')
{
// We have a record found in the 512 bytes of data in the buffer.
record.start = &asciiBuffer[i];
record.len = 0;
record.status = REC_FOUND_BUT_NOT_FLASHED;
}
break;
case REC_FOUND_BUT_NOT_FLASHED:
if((asciiBuffer[i] == 0x0A) || (asciiBuffer[i] == 0xFF))
{
// We have got a complete record. (0x0A is new line feed and 0xFF is End of file)
// Start the hex conversion from element
// 1. This will discard the ':' which is
// the start of the hex record.
ConvertAsciiToHex(&record.start[1],hexRec);
WriteHexRecord2Flash(hexRec);
record.status = REC_FLASHED;
}
break;
}
// Move to next byte in the buffer.
record.len ++;
}
if(record.status == REC_FOUND_BUT_NOT_FLASHED)
{
// We still have a half read record in the buffer. The next half part of the record is read
// when we read 512 bytes of data from the next file read.
memcpy(asciiBuffer, record.start, record.len);
pointer = record.len;
record.status = REC_NOT_FOUND;
}
else
{
pointer = 0;
}
// Blink LED at Faster rate to indicate programming is in progress.
led += 3;
mLED = ((led & 0x80) == 0);
}//while(1)
return 0;
}
If I remember well (very long time ago I used PIC32) you can add into your linker script:
MEMORY
{
//... other stuff
signature (RX) : ORIGIN = 0x9FC02FEC, length 0x4
}
then
SECTIONS
{
.signature_section:
{
BYTE(0x3b);
BYTE(0xdf);
BYTE(0xed);
BYTE(0x92);
}>signature
}
Googling around I also found out, that you could do that in your source code, I hope...
const int __attribute__((space(prog), address(0x9FC02FEC))) signature = 0x3bdfed92;
In my program I use an attribute to place a certain value at a certain location in memory space. My bootloader and App can read this location. This may be a simpler way for you to do this. This is using xc16 and a smaller part but I've done it on a PIC32 as well.
#define CHECK_SUM 0x45FB
#define CH_HIGH ((CHECK_SUM & 0xFF00) >> 8)
#define CH_LOW ((CHECK_SUM & 0x00FF) >> 0)
const char __attribute__((space(prog), address(APP_CS_LOC))) CHKSUM[2] = {CH_LOW,CH_HIGH};
Just a note, when you read it, it will be in the right format: HIGH->LOW
I just want to send an array adc_array=[w, x, y, z] from client to server. Below is the client side code whereas my server is in python which accepts json only. I get no error when i compile the code however get 2 warnings :
1- warning: pointer targets in passing argument 2 of 'UDPWrite' differ in signedness.
2- warning: no newline at end of file.
But at the server side, i am not able to receive the whole array, instead i just get the first character of the array i.e. [ .
I am new to C programming. I would really appreciate any help.
// Main function
void FlyportTask()
{
// Flyport connects to default network
WFConnect(WF_DEFAULT);
while(WFGetStat() != CONNECTED);
vTaskDelay(25);
UARTWrite(1,"Flyport Wi-fi connected...hello world!\r\n");
BOOL UdpSocketOpenRequest=TRUE;
BYTE UdpSocket=0;
// openinging UDP socket
if (UdpSocketOpenRequest) //open socket
{
UdpSocketOpenRequest=FALSE;
if (UdpSocket!=0) //if this is not equals to zero
{
UDPClientClose(UdpSocket);
}
UARTWrite(1,"OpenSocket\r\n");
UdpSocket= UDPClientOpen("10.0.0.106", "8000"); //Client socket opening
}
while(1)
{
//defining pointer
int *array_pointer;
int adc_array[4];
int j;
char buf[10]; //buffer to print
// I have made a separate function to get adc values which returns the pointer to the array.
array_pointer = get_adcval();
UARTWrite (1, "ADC Array\r\n");
for (j = 0; j < 4; j++)
{
adc_array[j] = *(array_pointer + j);
sprintf (buf, "%d", adc_array[j]);
UARTWrite (1, buf);
UARTWrite (1, "\n");
}
//if UDP socket is open, send the data
if ((UdpSocket!=0))
{
// defining pointer of serial_out
char *s_out;
int size;
// creating a JSON array from adc_array with 4 elements
cJSON * int_array = cJSON_CreateIntArray(adc_array,4);
// Serializing the array
s_out = cJSON_Print(int_array);
//Writing to the serial output/monitor
UARTWrite(1, "\r\narray to be sent\r\n");
UARTWrite(1, s_out);
UARTWrite(1,"\r\n");
// Assume adc_array=[1021, 1022, 1023, 1024]
// I get output [1021, 1022, 1023, 1024]
//compose message
size = strlen(s_out);
UDPWrite (UdpSocket, s_out, size);
// at the server side, i just receive only first character i.e. [
/*to free the memory */
free(s_out);
}
//
// remember to add delay vTaskDelay(50) 50ms
//remember to close the socket
}
}
You didn't allocated memory for s_out. even if it is printing correct result on UART but still it can be overwritten by any of the UARTWrite functions or strlen() function in the next lines. If it is overwritten then the "size" variable will get the number of bytes starting from the first byte to first null character in the memory (this is how strlen() functions). hence the "size" value can be totally random. it can be 0 or 1 or 1000. if the size is not correct then you will receive only "size" number of bytes. In your case it is possible that size is one. try printing size before UDPWrite. fix this problem by adding a malloc call before serializing the array.
If it doesn't work either then check your receiver side. is your receiver working fine if you send some dummy data from a tested python client (or any other tested or reliable client)? if no then there is some problem with your receiver.
Print out what strlen(s_out) returns, also print out the return value of UDPWrite ( I assume that like any write function this will be returning the size of the data which is written to the socket).
By reading the function names I presume you are using UDP transmission which is unreliable.
I am trying to design a pipelined cpu simulator. The code is fairly complex, atleast for me. There are multiple header and source files. The code compiles.
On running, it runs fine in the first iteration(clock cycle). But not so from the iteration. After spending hours on finding the fault, I found out what is wrong but don't know why. Following function:
MemoryAccess(ir, pc, ground, '0', instrMem);
fetches an instruction at index "pc" in instrMem and store it in "ir". Following are the declarations of the variables in the function:
typedef char bit32[33];
bit8 instrMem[4096]; /* instruction memory */
bit32 pc, ir, ground;
The problem is that from the second iteration onwards, value of "ir" remains "00000000". I have checked instrMem, the values are not all 0s. I also checked the working of MemoryAccess() using driver function. It works fine.
I can't undertand why it works fine for the first iteration and not from then on.
Can someone please help. Is there a way of finding out what's wrong?
following is the relevant part of main() function:
for(cycle=0; ; cycle++)
{
/* load IR with PC value */
printf("I am at the beginning of the cycle loop");
MemoryAccess(ir, pc, ground, '0', instrMem);
/* report fetched register values */
printf("cycle: %d, PC: %.32s (%d), IR: %.32s\n\t", cycle, pc, bit32toint(pc), ir);
/* halt check */
if (bit32toint(ir) == 0x0000003F) {
printf("\nmachine halted\n");
break;
}
/* PC + 4 data path */
RCAdder_32(pcPlus4, ground, pc, "00000000000000000000000000000100", '0');
/* jump data path */
shiftleftby2(jumpAddress, ir);
jumpAddress[0] = pcPlus4[0];
jumpAddress[1] = pcPlus4[1];
jumpAddress[2] = pcPlus4[2];
jumpAddress[3] = pcPlus4[3];
/* sign extended / shifted immediate data path */
signextend(immSignExt, &ir[16]);
shiftleftby2(immShifted, immSignExt);
/* control unit data path */
ControlUnit(ir, &ir[26], ®Write, ®Dest,
&memRead, &memWrite, &memToReg,
&jump, &branch, &aluSrc, aluOp);
/* register memory data path - read */
Mux2_5(regWriteAddr, &ir[11], &ir[16], regDest);
registerAccess(®Out1, ®Out2, &ir[6], &ir[11], regWriteAddr, regIn, '0');
/* alu data path */
Mux2_32(aluSrcVal, regOut2, immSignExt, aluSrc);
zero = ALU(&aluOut, regOut1, aluSrcVal, aluOp);
/* branch data path */
RCAdder_32(branchAddress, ground, pcPlus4, immShifted, '0');
Mux2_32(mbranchAddress, pcPlus4, branchAddress, AND2_1(zero, branch));
Mux2_32(pc, mbranchAddress, jumpAddress, jump);
/* main memory data path */
MemoryAccess(memOut, aluOut, regOut2, memWrite, mainMem);
Mux2_32(regIn, aluOut, memOut, memToReg);
/* register memory data path - write */
registerAccess(®Out1, ®Out2, &ir[6], &ir[11], regWriteAddr, regIn, regWrite);
/* dump register memory and signal information */
for (i=0; i < 14; i++) {
inttobitn(i, 5, tmp);
registerAccess(®Out1, ®Out2, tmp, &ir[11], regWriteAddr, regIn, '0');
printf("R%d: %d, ", i, bit32toint(regOut1));
}
printf("\b\b\n\tbranchAddress = %.32s (%d) jumpAddress = %.32s (%d)\n",
branchAddress, bit32toint(branchAddress), jumpAddress, bit32toint(jumpAddress));
printf("\topcode = %.6s, immSignExt = %.32s (%d), immShifted = %.32s (%d), PC+4 = %.32s (%d)\n",
ir, immSignExt, bit32toint(immSignExt), immShifted, bit32toint(immShifted), pcPlus4, bit32toint(pcPlus4));
printf("\tregWrite = %c, regDest = %c, memRead = %c, memWrite = %c, memToReg = %c, jump = %c, branch = %c, aluSrc = %c, aluOp = %.3s, zero = %c\n",
regWrite, regDest, memRead, memWrite, memToReg, jump, branch, aluSrc, aluOp, zero);
getchar();
}
Following is the MemoryAccess() function:
void MemoryAccess(bit32 read_out, bit32 addr, bit32 write_in, signal write_enable, bit8 memory[4096]){
int address= bitntoint(12, addr);
setbit8(read_out, memory[address]);
setbit8(&read_out[8], memory[address+1]);
setbit8(&read_out[16], memory[address+2]);
setbit8(&read_out[24], memory[address+3]);
if (write_enable){
setbit8(memory[address], write_in);
setbit8(memory[address+1], &write_in[8]);
setbit8(memory[address+2], &write_in[16]);
setbit8(memory[address+3], &write_in[24]);
}
}
Setbit8(a, b) copies b into a and appends '\0'.
To long for a comment:
1 The code shown does not seem to be increasing pc.
2 Although you pass '0' as writabel flag, it is not used as intended. You might like to change
if (write_enable)
to be
if (write_enable && ('0' != (*write_enable)))
Due to the former version memory is overwritten with what is referenced by the pointer passed into as 3rd parameter (write_in), which propably are 0s.
I'm trying to access a SPI sensor using the SPIDEV driver but my code gets stuck on IOCTL.
I'm running embedded Linux on the SAM9X5EK (mounting AT91SAM9G25). The device is connected to SPI0. I enabled CONFIG_SPI_SPIDEV and CONFIG_SPI_ATMEL in menuconfig and added the proper code to the BSP file:
static struct spi_board_info spidev_board_info[] {
{
.modalias = "spidev",
.max_speed_hz = 1000000,
.bus_num = 0,
.chips_select = 0,
.mode = SPI_MODE_3,
},
...
};
spi_register_board_info(spidev_board_info, ARRAY_SIZE(spidev_board_info));
1MHz is the maximum accepted by the sensor, I tried 500kHz but I get an error during Linux boot (too slow apparently). .bus_num and .chips_select should correct (I also tried all other combinations). SPI_MODE_3 I checked the datasheet for it.
I get no error while booting and devices appear correctly as /dev/spidevX.X. I manage to open the file and obtain a valid file descriptor. I'm now trying to access the device with the following code (inspired by examples I found online).
#define MY_SPIDEV_DELAY_USECS 100
// #define MY_SPIDEV_SPEED_HZ 1000000
#define MY_SPIDEV_BITS_PER_WORD 8
int spidevReadRegister(int fd,
unsigned int num_out_bytes,
unsigned char *out_buffer,
unsigned int num_in_bytes,
unsigned char *in_buffer)
{
struct spi_ioc_transfer mesg[2] = { {0}, };
uint8_t num_tr = 0;
int ret;
// Write data
mesg[0].tx_buf = (unsigned long)out_buffer;
mesg[0].rx_buf = (unsigned long)NULL;
mesg[0].len = num_out_bytes;
// mesg[0].delay_usecs = MY_SPIDEV_DELAY_USECS,
// mesg[0].speed_hz = MY_SPIDEV_SPEED_HZ;
mesg[0].bits_per_word = MY_SPIDEV_BITS_PER_WORD;
mesg[0].cs_change = 0;
num_tr++;
// Read data
mesg[1].tx_buf = (unsigned long)NULL;
mesg[1].rx_buf = (unsigned long)in_buffer;
mesg[1].len = num_in_bytes;
// mesg[1].delay_usecs = MY_SPIDEV_DELAY_USECS,
// mesg[1].speed_hz = MY_SPIDEV_SPEED_HZ;
mesg[1].bits_per_word = MY_SPIDEV_BITS_PER_WORD;
mesg[1].cs_change = 1;
num_tr++;
// Do the actual transmission
if(num_tr > 0)
{
ret = ioctl(fd, SPI_IOC_MESSAGE(num_tr), mesg);
if(ret == -1)
{
printf("Error: %d\n", errno);
return -1;
}
}
return 0;
}
Then I'm using this function:
#define OPTICAL_SENSOR_ADDR "/dev/spidev0.0"
...
int fd;
fd = open(OPTICAL_SENSOR_ADDR, O_RDWR);
if (fd<=0) {
printf("Device not found\n");
exit(1);
}
uint8_t buffer1[1] = {0x3a};
uint8_t buffer2[1] = {0};
spidevReadRegister(fd, 1, buffer1, 1, buffer2);
When I run it, the code get stuck on IOCTL!
I did this way because, in order to read a register on the sensor, I need to send a byte with its address in it and then get the answer back without changing CS (however, when I tried using write() and read() functions, while learning, I got the same result, stuck on them).
I'm aware that specifying .speed_hz causes a ENOPROTOOPT error on Atmel (I checked spidev.c) so I commented that part.
Why does it get stuck? I though it can be as the device is created but it actually doesn't "feel" any hardware. As I wasn't sure if hardware SPI0 corresponded to bus_num 0 or 1, I tried both, but still no success (btw, which one is it?).
UPDATE: I managed to have the SPI working! Half of it.. MOSI is transmitting the right data, but CLK doesn't start... any idea?
When I'm working with SPI I always use an oscyloscope to see the output of the io's. If you have a 4 channel scope ypu can easily debug the issue, and find out if you're axcessing the right io's, using the right speed, etc. I usually compare the signal I get to the datasheet diagram.
I think there are several issues here. First of all SPI is bidirectional. So if yo want to send something over the bus you also get something. Therefor always you have to provide a valid buffer to rx_buf and tx_buf.
Second, all members of the struct spi_ioc_transfer have to be initialized with a valid value. Otherwise they just point to some memory address and the underlying process is accessing arbitrary data, thus leading to unknown behavior.
Third, why do you use a for loop with ioctl? You already tell ioctl you haven an array of spi_ioc_transfer structs. So all defined transaction will be performed with one ioctl call.
Fourth ioctl needs a pointer to your struct array. So ioctl should look like this:
ret = ioctl(fd, SPI_IOC_MESSAGE(num_tr), &mesg);
You see there is room for improvement in your code.
This is how I do it in a c++ library for the raspberry pi. The whole library will soon be on github. I'll update my answer when it is done.
void SPIBus::spiReadWrite(std::vector<std::vector<uint8_t> > &data, uint32_t speed,
uint16_t delay, uint8_t bitsPerWord, uint8_t cs_change)
{
struct spi_ioc_transfer transfer[data.size()];
int i = 0;
for (std::vector<uint8_t> &d : data)
{
//see <linux/spi/spidev.h> for details!
transfer[i].tx_buf = reinterpret_cast<__u64>(d.data());
transfer[i].rx_buf = reinterpret_cast<__u64>(d.data());
transfer[i].len = d.size(); //number of bytes in vector
transfer[i].speed_hz = speed;
transfer[i].delay_usecs = delay;
transfer[i].bits_per_word = bitsPerWord;
transfer[i].cs_change = cs_change;
i++
}
int status = ioctl(this->fileDescriptor, SPI_IOC_MESSAGE(data.size()), &transfer);
if (status < 0)
{
std::string errMessage(strerror(errno));
throw std::runtime_error("Failed to do full duplex read/write operation "
"on SPI Bus " + this->deviceNode + ". Error message: " +
errMessage);
}
}