tools: improve usability on OpenBSD

So far, I hadn't managed to run those tools properly on OpenBSD. I
was too confused by its stty peculiarities. I'm still confused, but
at least I managed to make them work... most of the time...

tools/README.md

@@ -0,0 +1,28 @@
+# Tools
+
+This folder contains tools to communicate to Collapse OS machines from a modern
+environment or to manipulate a blkfs. 
+
+Communication tools all take a device path as a first argument. That device is
+the serial device that connects you to your machine. It's often a USB-to-TTL
+dongle. When `-` is specified, `stdin` is used as the device.
+
+Note that for these tools to work well, you need the serial device to be
+properly set up, TTY-wise. You'll probably want to do that with `stty`. The tool
+itself takes care of setting the regular stuff (`cs8`, `-parenb`, etc), but you
+need to set the speed. Here's an example working on OpenBSD:
+
+    $ ( stty 115200 ; ./upload - a000 os.bin ) <>/dev/cuaU0
+
+To be honest, I'm having a bit of troubles making these tools work as well on
+OpenBSD as they do in Linux. But it *does* work. Here are some advices:
+
+* Use `cuaXX` instead of `ttyXX`.
+* Run `cu -l /dev/cuaXX` before running your tool and run a dummy command to
+  make sure that the output buffer is flushed.
+
+On Linux, it's generally easier:
+
+* Run screen on the device (often `/dev/ttyUSBX`)
+* Quit with `CTRL+A :quit`
+* Run the tool on the same device

tools/blkup.c

@@ -22,13 +22,11 @@ int main(int argc, char **argv)
         fprintf(stderr, "Can't open %s.\n", argv[3]);
         return 1;
     }
-    int fd = open(argv[1], O_RDWR|O_NOCTTY|O_SYNC);
+    int fd = ttyopen(argv[1]);
     if (fd < 0) {
         fprintf(stderr, "Could not open %s\n", argv[1]);
         return 1;
     }
-    set_interface_attribs(fd, 0, 0);
-    set_blocking(fd, 1);
     char s[0x40];
     char buf[1024] = {0};
     sendcmdp(fd, ": _ 1024 0 DO KEY DUP .x I BLK( + C! LOOP ;");

tools/common.c

@@ -4,18 +4,33 @@
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
+#include <fcntl.h>
+
+#define BREATHE usleep(2000)
+//#define DEBUG(...) fprintf(stderr, __VA_ARGS__)
+#define DEBUG(...)
 
 void mread(int fd, char *s, int count)
 {
     while (count) {
         while (read(fd, s, 1) == 0) {
-            usleep(1000);
+            BREATHE;
         }
         s++;
         count--;
     }
 }
 
+// Make sure that nothing is waiting in the pipeline
+static void mempty(int fd)
+{
+    char c;
+    while (read(fd, &c, 1) == 1) {
+        DEBUG("Emptying %d\n", c);
+        BREATHE;
+    }
+}
+
 static void mexpect(int fd, char ec)
 {
     char c;
@@ -36,19 +51,23 @@ void readprompt(int fd)
 
 void sendcmd(int fd, char *cmd)
 {
+    DEBUG("Sending %s\n", cmd);
     char junk[2];
     while (*cmd) {
+        DEBUG("W: %d\n", *cmd);
         write(fd, cmd, 1);
+        BREATHE;
         read(fd, &junk, 1);
+        DEBUG("R: %d\n", *junk);
         cmd++;
         // The other side is sometimes much slower than us and if we don't let
         // it breathe, it can choke.
-        usleep(1000);
+        BREATHE;
     }
     write(fd, "\r", 1);
     mexpect(fd, '\r');
     mexpect(fd, '\n');
-    usleep(1000);
+    BREATHE;
 }
 
 // Send a cmd and also read the " ok" prompt
@@ -79,6 +98,7 @@ int set_interface_attribs(int fd, int speed, int parity)
     // disable IGNBRK for mismatched speed tests; otherwise receive break
     // as \000 chars
     tty.c_iflag &= ~IGNBRK;         // disable break processing
+    tty.c_iflag &= ~ICRNL;          // disable CR->NL mapping
     tty.c_lflag = 0;                // no signaling chars, no echo,
                                     // no canonical processing
     tty.c_oflag = 0;                // no remapping, no delays
@@ -118,3 +138,15 @@ void set_blocking(int fd, int should_block)
     }
 }
 
+int ttyopen(char *devname)
+{
+    int fd = 0;
+    if (strcmp(devname, "-") != 0) {
+        fd = open(devname, O_RDWR|O_NOCTTY|O_SYNC);
+    }
+    set_interface_attribs(fd, 0, 0);
+    set_blocking(fd, 0);
+    mempty(fd);
+    set_blocking(fd, 1);
+    return fd;
+}

tools/common.h

@@ -4,4 +4,4 @@ void mread(int fd, char *s, int count);
 void readprompt(int fd);
 int set_interface_attribs(int fd, int speed, int parity);
 void set_blocking(int fd, int should_block);
-
+int ttyopen(char *devname);

tools/exec.c

@@ -14,12 +14,11 @@ int main(int argc, char **argv)
         fprintf(stderr, "Usage: ./exec device\n");
         return 1;
     }
-    int fd = open(argv[1], O_RDWR|O_NOCTTY|O_SYNC);
+    int fd = ttyopen(argv[1]);
     if (fd < 0) {
         fprintf(stderr, "Could not open %s\n", argv[1]);
         return 1;
     }
-    set_interface_attribs(fd, 0, 0);
     set_blocking(fd, 0);
     int c = getchar();
     while (c != EOF) {

tools/memdump.c

@@ -27,13 +27,17 @@ int main(int argc, char **argv)
         return 0;
     }
 
-    int fd = open(argv[1], O_RDWR|O_NOCTTY);
+    int fd = ttyopen(argv[1]);
+    if (fd < 0) {
+        fprintf(stderr, "Could not open %s\n", argv[1]);
+        return 1;
+    }
     char s[0x30];
     sprintf(s, ": _ 0x%04x 0x%04x DO I @ .x LOOP ; _", memptr+bytecount, memptr);
     sendcmd(fd, s);
 
     for (int i=0; i<bytecount; i++) {
-        read(fd, s, 2); // read hex pair
+        mread(fd, s, 2); // read hex pair
         s[2] = 0; // null terminate
         unsigned char c = strtol(s, NULL, 16);
         putchar(c);

tools/upload.c

@@ -35,13 +35,11 @@ int main(int argc, char **argv)
         return 1;
     }
     rewind(fp);
-    int fd = open(argv[1], O_RDWR|O_NOCTTY|O_SYNC);
+    int fd = ttyopen(argv[1]);
     if (fd < 0) {
         fprintf(stderr, "Could not open %s\n", argv[1]);
         return 1;
     }
-    set_interface_attribs(fd, 0, 0);
-    set_blocking(fd, 1);
     char s[0x40];
     sprintf(s,
         ": _ 0x%04x 0x%04x DO KEY DUP .x I C! LOOP ; _",
@@ -50,8 +48,8 @@ int main(int argc, char **argv)
 
     int returncode = 0;
     while (fread(s, 1, 1, fp)) {
-        putchar('.');
-        fflush(stdout);
+        putc('.', stderr);
+        fflush(stderr);
         unsigned char c = s[0];
         write(fd, &c, 1);
         usleep(1000); // let it breathe
@@ -69,8 +67,11 @@ int main(int argc, char **argv)
     }
     readprompt(fd);
     sendcmdp(fd, "FORGET _");
-    printf("Done!\n");
+    fprintf(stderr, "Done!\n");
     fclose(fp);
+    if (fd > 0) {
+        close(fd);
+    }
     return returncode;
 }