view target-utils/libcommon/cmdentry.c @ 407:19e5a3e2f9c0

fcup-settime: moved time() retrieval a little closer to the output A fundamental problem with all simple time transfer tools is that there is always some delay between the time retrieval on the source system and that transmitted time being set on the destination, and the resulting time on the destination system is off by that delay amount. This delay cannot be fully eliminated when working in a simple environment like ours, but we should make our best effort to minimize it. In the present case, moving the atinterf_init() call before the time() retrieval should make a teensy-tiny improvement.
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 11 Aug 2018 21:52:17 +0000
parents e7502631a0f9
children
line wrap: on
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/*
 * This module implements ASCII command entry via the serial port,
 * with normal echo and minimal editing (rubout and kill).
 *
 * The command string buffer is bss-allocated here as well.  It is
 * sized to allow a maximum-size S-record to be sent as a command,
 * as that is how we expect flash loading and XRAM chain-loading
 * to be done.
 */

#define	MAXCMD	527

char command[MAXCMD+1];

/*
 * The command_entry() function takes no arguments, and begins by waiting
 * for serial input - hence the prompt should be printed before calling it.
 *
 * This function returns when one of the following characters is received:
 * CR - accepts the command
 * ^C or ^U - cancels the command
 *
 * The return value is non-zero if a non-empty command was accepted with CR,
 * or 0 if the user hit CR with no input or if the command was canceled
 * with ^C or ^U.  In any case a CRLF is sent out the serial port
 * to close the input echo line before this function returns.
 */
command_entry()
{
	int inlen, ch;

	for (inlen = 0; ; ) {
		ch = mygetchar();
		if (ch >= ' ' && ch <= '~') {
			if (inlen < MAXCMD) {
				command[inlen++] = ch;
				putchar(ch);
			} else
				/* putchar(7) */;
			continue;
		}
		switch (ch) {
		case '\r':
		case '\n':
			command[inlen] = '\0';
			putchar('\n');
			return(inlen);
		case '\b':	/* BS */
		case 0x7F:	/* DEL */
			if (inlen) {
				putchar('\b');
				putchar(' ');
				putchar('\b');
				inlen--;
			} else
				/* putchar(7) */;
			continue;
		case 0x03:	/* ^C */
			putchar('^');
			putchar('C');
			putchar('\n');
			return(0);
		case 0x15:	/* ^U */
			putchar('^');
			putchar('U');
			putchar('\n');
			return(0);
		default:
			/* putchar(7) */;
		}
	}
}