eeprom-programmer/firmware/src/parsing.c

123 lines
3.2 KiB
C

#include "config.h"
#include "parsing.h"
#include "commands.h"
#include "uart.h"
#include <string.h>
#include <stdbool.h>
#include <stdlib.h>
#include <util/delay.h>
// Read and parse command line and dispatch command
void parseNextCommand() {
const int bufferLength = 80;
char buffer[bufferLength];
// Read next command
CommandLine cmdLine = readNextCommand(buffer, bufferLength);
// Execute command
executeCommand(cmdLine);
}
// Read next command line from UART
CommandLine readNextCommand(char* buffer, uint8_t bufferLength) {
while (1) {
// Read next command
int readChars = uartGetLine(buffer, bufferLength);
if (readChars >= bufferLength - 1) {
// Reading was aborted after bufferLength-1 characters to prevent buffer overflow.
uartPutLine("ERROR buffer overflow, discarding line");
// Discard everything until we read an actual end of line
for (unsigned char c = 0; c != '\n' && c != '\r'; c = uartGetChar());
readChars = 0;
}
if (readChars != 0) {
return tokenizeCommand(buffer);
}
}
}
// Splits a command "CMD ARGS" to two strings "CMD" and "ARGS". Returns pointer
// to "ARGS" or NULL if no arguments were found. Changes the input string!
CommandLine tokenizeCommand(char* cmd) {
CommandLine cmdLine = {
cmd,
NULL
};
if (cmd == NULL) {
return cmdLine;
}
// Search for a space character
for (char* p = cmd; *p != '\0'; p++) {
if (*p == ' ') {
// Split strings by replacing the space by \0, then set argument pointer.
*p++ = '\0';
cmdLine.arg = p;
break;
}
}
return cmdLine;
}
// Address parsing
bool parseSingleAddressTo(char* addressStr, address_t* address) {
if (addressStr == NULL || strlen(addressStr) != 4 || address == NULL) {
return false;
}
for (char* p = addressStr; *p != '\0'; p++) {
if ((*p < '0' || *p > '9') && (*p < 'A' || *p > 'F')) {
return false;
}
}
*address = strtol(addressStr, NULL, 16);
return true;
}
// Parses a single 2-byte hexadecimal address string "XXXX:YYYY" to an actual address.
AddressRange parseSingleAddress(char* addressStr) {
AddressRange range = {true, 0, 0};
if (!parseSingleAddressTo(addressStr, &range.from)) {
return (AddressRange) {false, 0, 0};
}
range.to = range.from;
return range;
}
// Parses a hexadecimal address range string "XXXX:YYYY" to actual addresses.
// A single address "XXXX" is equivalent to "XXXX:XXXX", with from == to.
AddressRange parseAddressRange(char* addressStr) {
if (addressStr == NULL) {
return (AddressRange) {false, 0, 0};
}
int len = strlen(addressStr);
if (len != 4 && len != 9) {
return (AddressRange) {false, 0, 0};
}
if (len == 9) {
if (addressStr[4] != ':') {
return (AddressRange) {false, 0, 0};
}
addressStr[4] = '\0';
}
AddressRange range = parseSingleAddress(addressStr);
if (range.isValid && len == 9) {
if (!parseSingleAddressTo(addressStr + 5, &range.to)) {
return (AddressRange) {false, 0, 0};
}
}
return range;
}