update pi section

app/views/pages/arm/qemu.html.haml

@@ -2,7 +2,7 @@
 
 %h1= title "How to configure Qemu"
 
-%h2#target-pi-on-mac Target Pi on Mac
+%h2 Target Pi on Mac
 %p So even the idea is to run software on the Pi, not everyone has a Pi (yet :-)
 %p Others, like me, prefer to develop on a laptop and not carry the Pi around.
 %p For all those, this here explains how to emulate the Pi on a Mac.
@@ -10,30 +10,33 @@
   Even if you have a Pi,
   =link_to "this explains",  "remote_pi.html"
   a nice way to develop with it.
-%h3#replace-the-buggy-llvm Replace the buggy llvm
+
-%p Written April 2014: as of writing the latest and greatest llvm based gcc (5.1) on Maverick (10.9) has a bug that makes qemu hang.
+%h3 Qemu
-%p So type gcc -v and if the output contains “LLVM version 5.1”, you must install gcc4.2. Easily done with homebrew:
+%p Get the Qemu. There may be other emulators out there, and i have read of armulator, but this is what i found discribed and it works and is “easy enough”.
 %pre
   %code
     :preserve
-      brew install https://raw.github.com/Homebrew/homebrew-dupes/master/apple-gcc42.rb
+      brew install qemu
-%p This will not interfere with the systems compiler as the gcc4.2 has postfixed executables (ie gcc-4.2)
+
-%h3#qemu Qemu
+%h3 Pi images
-%p Then its time to get the Qemu. There may be other emulators out there, and i have read of armulator, but this is what i found discribed and it works and is “easy enough”.
+
-%pre
-  %code
-    :preserve
-      brew install qemu --env=std --cc=gcc-4.2
-%p For people not on Maverick it may work without the -cc option.
-%h3#pi-images Pi images
 %p Create a directory for the stuff on your mac, ie pi.
 %p Get the latest Raspian image.
-%p There seems to be some chicken and egg problem, so quemu needs the kernel seperately. There is one in the links.
-%h3#configure Configure
 %p
-  In the blog post there is some fun configuration, I did it and it works. Not sure what happens if you don’t.
+  There seems to be some chicken and egg problem, so qemu needs the kernel separately.
-  The booting is described below (you may or may not need an extra init=/bin/bash in the root… quotes), so boot your Pi and then configure:
+  There is one in the links.
-%p nano /etc/ld.so.preload
+
+%h3 Configure
+
+%p
+  In the blog post there is some fun configuration, I did it and it works.
+  Not sure what happens if you don’t.
+  The booting is described below (you may or may not need an extra init=/bin/bash in the root… quotes),
+  so boot your Pi and then configure:
+%p
+  %pre
+    %code
+      nano /etc/ld.so.preload
 %p Put a # in front of the first to comment it out. Should just be one line there.
 %p Press ctrl-x then y then enter to save and exit.
 %p (Optional) Create a file /etc/udev/rules.d/90-qemu.rules with the following content:
@@ -53,8 +56,8 @@
     :preserve
       qemu-system-arm -kernel kernel-qemu -cpu arm1176 -m 256 -M versatilepb -no-reboot -serial stdio -append 'root=/dev/sda2 panic=1 rootfstype=ext4 rw' -hda raspbian.img -redir tcp:2222::22
 %ul
-  %li the cpu is what braodcom precifies, ok
+  %li the cpu is what broadcom specifies, ok
-  %li memory is unfortuantely hardcoded in the versatilepb “machine”
+  %li memory is unfortunately hardcoded in the versatilepb “machine”
   %li the kernel is the file name of the kernel you downloaded (or extracted)
   %li raspbian.img is the image you downloaded. Renamed as it probably had the datestamp on it
   %li the redir redircts the port 2222 to let you log into the pi
@@ -92,11 +95,14 @@
       resize2fs
 %h2#links Links
 %p
-  Blog post:
+  Blog post (i used):
   =ext_link "http://xecdesign.com/qemu-emulating-raspberry-pi-the-easy-way/", "http://xecdesign.com/qemu-emulating-raspberry-pi-the-easy-way/"
+%p
+  More Recent post (i googled):
+  =ext_link "https://blog.agchapman.com/using-qemu-to-emulate-a-raspberry-pi/", "https://blog.agchapman.com/using-qemu-to-emulate-a-raspberry-pi/"
 %p
   Kernel:
   =ext_link "http://xecdesign.com/downloads/linux-qemu/kernel-qemu", "http://xecdesign.com/downloads/linux-qemu/kernel-qemu"
 %p
-  Rasbian file system(preferably be torrent):
+  Rasbian file system(preferably by torrent):
   =ext_link "http://www.raspberrypi.org/downloads/", "http://www.raspberrypi.org/downloads/"

app/views/pages/arm/remote_pi.html.haml

@@ -2,7 +2,7 @@
 
 %h1= title "How to use a remote pi"
 
-%h3#headless Headless
+%h3 Headless
 %p The pi is a strange mix, development board and full pc in one. Some people use it as a pc, but not me.
 %p I use the pi because it is the same price as an Arduino, but much more powerful.
 %p As such i don’t use the keyboard or display and that is called headless mode, logging in with ssh.
@@ -11,7 +11,7 @@
     :preserve
       ssh -p 2222 -l pi localhost
 %p the -p 2222 is only needed for the qemu version, not the real pi.
-%h3#authorized Authorized
+%h3 Authorise yourself
 %p
   Over ssh one can use many other tools, but the password soon gets to be a pain.
   So the first thing i do is copy my public key over to the pi. This will allow login without password.
@@ -22,20 +22,33 @@
 %p
   This assumes a fresh pi, otherwise you have to append your key to the authorized ones. Also if it complains about no
   id_rsa.pub then you have to generate a key pair (public/private) using ssh-keygen (no password, otherwise you’ll be typing that)
-%h3#syncing Syncing
+
+%h3 Sync the working tree
 %p
-  Off course I do all that to be able to actually work on my machine. On the Pi my keyboard doesn’t even work and
+  Off course I do all that to be able to actually work on my machine.
-  i’d have to use emacs or nano instead of TextMate. So i need to get the files accross.
+  On the Pi my keyboard doesn’t even work and i’d have to use emacs or nano instead
-  For this there is a million ways, but since i just go one way (mac to pi) i use rsync (over ssh).
+  of Atom. So i need to get the files across.
-%p I set up a directory (home) in my pi directory (on the mac), that i copy to the home directory on the pi using:
+  %br
+  For this there is a million ways, but since i just go one way (mac to pi)
+  i use rsync (over ssh).
+%p
+  I set up a directory (home) in my pi directory (on the mac),
+  that i copy to the home directory on the pi using:
 %pre
   %code
     :preserve
       rsync -r -a -v -e "ssh -l pi -p 2222" ~/pi/home/ localhost:/home/pi
+
 %p The pi/home is on my laptop and the command transfers all files to /home/pi , the default directory of the pi user.
-%h3#automatic-sync Automatic sync
+
-%p Transferring files is off course nice, but having to do it by hand after saving quickly becomes tedious.
+%h3 Automatic sync
-%p Fswatch to the rescue. It will watch the filesystem (fs) for changes. Install with brew install fswatch
+
+%p
+  Transferring files is off course nice, but having to do it by hand after
+  saving quickly becomes tedious.
+%p
+  Fswatch to the rescue. It will watch the filesystem (fs) for changes.
+  Install with 'brew install fswatch'
 %p
   Then you can store the above rsync command in a shell script, say sync.sh.
   Add afplay “/System/Library/Sounds/Morse.aiff” if you like to know it worked.
@@ -43,15 +56,18 @@
 %pre
   %code
     :preserve
-      fswatch ~/pi/home/ sync.sh
+      fswatch -o ~/pi/home | xargs -n1 -I{} ~/sync.sh
-%p And hear the ping each time you save.
+%p
-%h2#conclusion Conclusion
+  And hear the ping each time you save. (btw -I{} makes it so the file name that changed
+  does not get passed on. Rsync figures that out)
+
+%h2 Conclusion
 %p So the total setup involves the qemu set up as described. To work i
 %ul
   %li start the terminal (iterm)
   %li start the pi, with my alias “pi” *
   %li log in to the pi in it’s window
-  %li open textmate with the directory i work (within the home)
+  %li open atom with the directory i work (within the home)
-  %li
+  %li edit, save, wait for ping, alt-tab to pi window, run my whatever and repeat until it’s time for tea
-    %p edit, save, wait for ping, alt-tab to pi window, run my whatever and repeat until it’s time for tea
+
-  %li (i don’t log into the prompt it gives in item so as not to accidentally quit the qemu session with ctr-c )
+PS: (i don’t log into the prompt it gives in item so as not to accidentally quit the qemu session with ctr-c )