From 971b3af10e8910ea8e29819e36dbd003eadd322a Mon Sep 17 00:00:00 2001 From: Torsten Ruger Date: Tue, 27 May 2014 12:30:12 +0300 Subject: [PATCH] adds the emulator and ssh howto pages --- _layouts/site.html | 3 +++ qemu.md | 66 ++++++++++++++++++++++++++-------------------- remote_pi.md | 24 ++++++++--------- 3 files changed, 52 insertions(+), 41 deletions(-) diff --git a/_layouts/site.html b/_layouts/site.html index 940b63c..374b941 100644 --- a/_layouts/site.html +++ b/_layouts/site.html @@ -47,6 +47,9 @@
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    • diff --git a/qemu.md b/qemu.md index f0130af..fa29334 100644 --- a/qemu.md +++ b/qemu.md @@ -3,8 +3,8 @@ layout: site title: How to configure Qemu --- -Target Pi on Mac ----------------- +##Target Pi on Mac + So even the idea is to run software on the Pi, not everyone has a Pi (yet :-) @@ -12,28 +12,28 @@ Others, like me, prefer to develop on a laptop and not carry the Pi around. For all those, this here explains how to emulate the Pi on a Mac. -Replace the buggy llvm ------------------------ +Even if you have a Pi, [this explains](/remote_pi.html) a nice way to develop with it. + +###Replace the buggy llvm + 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. So type gcc -v and if the output contains "LLVM version 5.1", you must install gcc4.2. Easily donw with homebrew: -brew install https://raw.github.com/Homebrew/homebrew-dupes/master/apple-gcc42.rb + brew install https://raw.github.com/Homebrew/homebrew-dupes/master/apple-gcc42.rb This will not interfere with the systems compiler as the gcc4.3 has postfixed executables (ie gcc-4.2) -Qemu ----- +###Qemu 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". -brew install qemu --env=std --cc=gcc-4.2 + brew install qemu --env=std --cc=gcc-4.2 For people not on Maverick it may work without the -cc option. -Pi images ----------- +###Pi images Create a directory for the stuff on your mac, ie pi. @@ -41,32 +41,31 @@ Get the latest Raspian image. There seems to be some chicken and egg problem, so quemu needs the kernel seperately. There is one in the links. -Configure ---------- +###Configure 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: -nano /etc/ld.so.preload + nano /etc/ld.so.preload Put a # in front of the first to comment it out. Should just be one line there. Press ctrl-x then y then enter to save and exit. (Optional) Create a file /etc/udev/rules.d/90-qemu.rules with the following content: -KERNEL=="sda", SYMLINK+="mmcblk0" -KERNEL=="sda?", SYMLINK+="mmcblk0p%n" -KERNEL=="sda2", SYMLINK+="root" + + KERNEL=="sda", SYMLINK+="mmcblk0" + KERNEL=="sda?", SYMLINK+="mmcblk0p%n" + KERNEL=="sda2", SYMLINK+="root" The kernel sees the disk as /dev/sda, while a real pi sees /dev/mmcblk0. This will create symlinks to be more consistent with the real pi. -Boot ------ +###Boot There is quite a bit to the command line to boot the pi (i have an alias), here it is: -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 + 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 - the cpu is what braodcom precifies, ok - memory is unfortuantely hardcoded in the versatilepb "machine" @@ -74,20 +73,27 @@ qemu-system-arm -kernel kernel-qemu -cpu arm1176 -m 256 -M versatilepb -no-reboo - raspbian.img is the image you downloaded. Renamed as it probably had the datestamp on it - the redir redircts the port 2222 to let you log into the pi -So "ssh -p 2222 -l pi localhost" will get you "in". Ie username pi (password raspberry is the default) and port 2222 +So + + ssh -p 2222 -l pi localhost + +will get you "in". Ie username pi (password raspberry is the default) and port 2222 Qemu bridges the network (that it emulates), and so your pi is now as connected as your mac. -More Disk ---------- +###More Disk The image that you download has only 200Mb free. Since the gcc is included and we're developing (tiny little files of) ruby, this may be ok. If not there is a 3 step procedure to up the space. -1. dd if=/dev/zero bs=1m count=2048 >> raspbian.img + dd if=/dev/zero bs=1m count=2048 >> raspbian.img The 2048 gets you 2Gb as we specified 1m (meg). -2. On the pi launch "sudo fdisk /dev/sda" . This will probably only work if your do the (Optional) config above. +On the pi launch + + sudo fdisk /dev/sda + +This will probably only work if your do the (Optional) config above. Say p, and write down the start of the second partition (122880 for me). d 2 will delete the second partition @@ -96,11 +102,15 @@ write the number as start and just return to the end. p to check w to write and quit. -3. Reboot, and run resize2fs +Reboot, and run + + resize2fs Links ----- -Blog post: http://xecdesign.com/qemu-emulating-raspberry-pi-the-easy-way/ -Kernel: http://xecdesign.com/downloads/linux-qemu/kernel-qemu -Rasbian file system(preferably be torrent): http://www.raspberrypi.org/downloads/ +Blog post: [http://xecdesign.com/qemu-emulating-raspberry-pi-the-easy-way/](http://xecdesign.com/qemu-emulating-raspberry-pi-the-easy-way/) + +Kernel: [http://xecdesign.com/downloads/linux-qemu/kernel-qemu](http://xecdesign.com/downloads/linux-qemu/kernel-qemu) + +Rasbian file system(preferably be torrent): [http://www.raspberrypi.org/downloads/](http://www.raspberrypi.org/downloads/) diff --git a/remote_pi.md b/remote_pi.md index 51b5949..00f446c 100644 --- a/remote_pi.md +++ b/remote_pi.md @@ -3,8 +3,7 @@ layout: site title: How to use a remote pi --- -Headless --------- +###Headless The pi is a strange mix, development board and full pc in one. Some people use it as a pc, but not me. @@ -12,23 +11,21 @@ I use the pi because it is the same price as an Arduino, but much more powerful. As such i don't use the keyboard or display and that is called headless mode, logging in with ssh. -ssh -p 2222 -l pi localhost + ssh -p 2222 -l pi localhost -the -p 2222 is only needed for the qemu version, not the real pi. + the -p 2222 is only needed for the qemu version, not the real pi. -Authorized ------------ +###Authorized 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. -scp -P 2222 .ssh/id_rsa.pub pi@localhost:.ssh/authorized_keys + scp -P 2222 .ssh/id_rsa.pub pi@localhost:.ssh/authorized_keys 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) -Syncing -------- +###Syncing 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 i'd have to use emacs or nano instead of TextMate. So i need to get the files accross. @@ -36,12 +33,11 @@ For this there is a million ways, but since i just go one way (mac to pi) i use I set up a directory (home) in my pi directory (on the mac), that i copy to the home directory on the pi using: -rsync -r -a -v -e "ssh -l pi -p 2222" ~/pi/home/ localhost:/home/pi + rsync -r -a -v -e "ssh -l pi -p 2222" ~/pi/home/ localhost:/home/pi The pi/home is on my laptop and the command transfers all files to /home/pi , the default directory of the pi user. -Automatic sync --------------- +###Automatic sync Transferring files is off course nice, but having to do it by hand after saving quickly becomes tedious. @@ -50,7 +46,9 @@ Fswatch to the rescue. It will watch the filesystem (fs) for changes. Install wi 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. -Then just run fswatch ~/pi/home/ sync.sh +Then just run + + fswatch ~/pi/home/ sync.sh And hear the ping each time you save.