From 6885f97fa1068cc319d4833fa3acbbb36b9ae8bc Mon Sep 17 00:00:00 2001
From: aap <aap@papnet.eu>
Date: Tue, 5 Mar 2019 11:55:33 +0100
Subject: [PATCH] emu: some cmd cleanup; DT stuff; pre-loaded memory files

---
 misc/mkpty33.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 144 insertions(+)
 create mode 100644 misc/mkpty33.c

diff --git a/misc/mkpty33.c b/misc/mkpty33.c
new file mode 100644
index 0000000..eaf4609
--- /dev/null
+++ b/misc/mkpty33.c
@@ -0,0 +1,144 @@
+/* Creates a pty and connects it to the process tty.
+ * As an optional argument it takes a filename and symlinks /dev/pts/N. */ 
+
+/* Pretend to be an ASR33 of sorts */
+
+#define _XOPEN_SOURCE 600	/* for ptys */
+#define _DEFAULT_SOURCE		/* for cfmakeraw */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <unistd.h>
+#include <poll.h>
+#include <errno.h>
+#include <time.h>
+
+struct termios tiosaved;
+
+int
+raw(int fd)
+{
+	struct termios tio;
+	if(tcgetattr(fd, &tio) < 0) return -1;
+	tiosaved = tio;
+	cfmakeraw(&tio);
+	if(tcsetattr(fd, TCSAFLUSH, &tio) < 0) return -1;
+	return 0;
+}
+
+int
+reset(int fd)
+{
+	if(tcsetattr(0, TCSAFLUSH, &tiosaved) < 0) return -1;
+	return 0;
+}
+
+#define BAUD 30
+
+struct timespec slp = { 0, 1000*1000*1000 / BAUD };
+struct timespec hupslp = { 0, 100*1000*1000 };
+
+//#define SLEEP nanosleep(&slp, NULL)
+#define SLEEP
+
+void
+readwrite(int ttyin, int ttyout, int ptyin, int ptyout)
+{
+	int n;
+	struct pollfd pfd[2];
+	char c;
+
+	pfd[0].fd = ptyin;
+	pfd[0].events = POLLIN;
+	pfd[1].fd = ttyin;
+	pfd[1].events = POLLIN;
+	while(pfd[0].fd != -1){
+		n = poll(pfd, 2, -1);
+		if(n < 0){
+			perror("error poll");
+			return;
+		}
+		if(n == 0)
+			return;
+		if(pfd[0].revents & POLLHUP)
+			nanosleep(&hupslp, NULL);
+		/* read from pty, write to tty */
+		if(pfd[0].revents & POLLIN){
+			if(n = read(ptyin, &c, 1), n <= 0)
+				return;
+			else{
+				c &= 0177;	// is this needed?
+//if(c == '\a') c = '.';
+				if(c < 0140)
+					write(ttyout, &c, 1);
+				SLEEP;
+			}
+		}
+		/* read from tty, write to pty */
+		if(pfd[1].revents & POLLIN){
+			if(n = read(ttyin, &c, 1), n <= 0)
+				return;
+			else{
+				c &= 0177;	// needed?
+				if(c == 035)
+					return;
+				/* map character reasonably */
+				if(c == 033) c = 0175;	// esc to altmode
+				if(c >= 'a' && c <= 'z')	// to upper
+					c &= ~040;
+				c |= 0200;	// needed?
+				write(ptyout, &c, 1);
+				SLEEP;
+			}
+		}
+	}
+}
+
+int
+main(int argc, char *argv[])
+{
+	int fd;
+	int slv;
+	const char *ptylink;
+
+	ptylink = NULL;
+	if(argc > 1)
+		ptylink = argv[1];
+
+	fd = posix_openpt(O_RDWR);
+	if(fd < 0)
+		return 1;
+	if(grantpt(fd) < 0)
+		return 2;
+	if(unlockpt(fd) < 0)
+		return 3;
+
+	if(ptylink){
+		unlink(ptylink);
+		if(symlink(ptsname(fd), ptylink) < 0)
+			fprintf(stderr, "Error: %s\n", strerror(errno));
+	}
+
+	printf("%s\n", ptsname(fd));
+
+	slv = open(ptsname(fd), O_RDWR);
+	if(slv < 0)
+		return 4;
+	raw(slv);
+	close(slv);
+
+	raw(0);
+
+	readwrite(0, 1, fd, fd);
+	close(fd);
+
+	reset(0);
+
+	if(ptylink)
+		unlink(ptylink);
+
+	return 0;
+}