OSD:Linux-development-environment-setup-notes
From The Neuros Technology Wiki
We're working on cleaning this up, in the meantime, if you're looking for the easiest way to get started, check out OSD_Virtual_Machine_Development or if you're looking to really dig in, check outDerobert's_Guide_to_Hacking_the_On-Screen_Display
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[edit] General Description
With the developer board or development hardware on hand, all you need to set up the development environment with your host Linux PC is a serial cable, an Ethernet hub and two Ethernet cables. Well, you know what to do if you don't have the power adapter. ;-)
*NOTE: The OSD has an internal switch like a hub meaning you can actually connect an standard Ethernet cable directly between the PC and the OSD if you want.
Software-wise, on your host PC, you'll need to set up a TFTP server and NFS server, you'll also need a terminal program. With U-boot already installed on your Neuros target hardware, you can boot the Linux kernel via TFTP from your host PC and in turn the kernel can mount rootfs from the NFS drive. Thus you don't need to burn and FLASH every time you change the code, be it on Kernel side or the application itself.
In the following HOWTO the expression #BSP_ROOT# is to be replaced with the actual directory in which you checked out the BSP package from Neuros' CVS.
[edit] sudo
In order to set up the bsp, you'll need root permission to create the device root file system. The setup script and Makefiles use the sudo command to obtain root access.
In order for the sudo command to work correctly, you must have an entry for your user ID in /etc/sudoers. You need to edit this file as the root user. Also, you can add a default timestamp entry to disable sudo from periodically asking for your user password. The following two lines need to be added to the /etc/sudoers file.
Defaults:<user id> timestamp_timeout=-1 <user id> ALL=(ALL) ALL
The relevant portion of the /etc/sudoers I use is:
# Defaults specification Defaults:mgao timestamp_timeout=-1 # User privilege specification root ALL=(ALL) ALL mgao ALL=(ALL) ALL
[edit] Terminal program
You can choose whatever terminal program you like, I use kermit, minicom is another choice. I use /dev/ttyS0 and you need to set bps to 115200.
Instructions to set up minicom
To bring up the setup sudo minicom -s go to "serial port setup" use /dev/ttyS0 e->115200 8N1 without any flowcontrol go to "Modem" part, erase init/reset strings. Save as default. Bring up minicom minicom -w #turn on word wrapping.
Instructions for kermit
Create a file called .kermrc in your home directory with the following contents: set line /dev/ttyS0 set speed 115200 set carrier-watch off set handshake none set flow-control none robust set file type bin set file name lit set rec pack 1000 set send pack 1000 set window 5 now start the program with kermit -c
[edit] tftp
tftp server package needs to be installed on host PC.
edit /etc/xinetd.d/tftp to, turn disable = no server_args = -s #BSP_ROOT#
reload the config for tftp server ps ax | grep inetd kill -1 [inetd process ID]
or more easily sudo /etc/init.d/xinetd restart
Debian users just add the following line to /etc/inetd.conf
tftp dgram udp wait nobody /usr/sbin/tcpd /usr/sbin/in.tftpd #BSP_ROOT#
[edit] NFS
The nfs server package needs to be installed on host PC. Install it (if it isn't already). In some distributions (like debian) it's called nfs-kernel-server instead of just nfs. Be sure to install the nfs server that runs in kernel space. The user space version (nfs-user-server) is harder to configure.
Edit /etc/exports and add something like the following:
# NFS access dir #BSP_ROOT# 192.168.10.69(rw,sync,no_root_squash)
where #BSP_ROOT# is the directory you are exporting to the OSD (BSP Root) and 192.168.10.69 is the IP address of the OSD.
Then, start, restart, or reload the nfs server by running
/etc/init.d/nfs restart
(Again, it might be may be called nfs-kernel-server instead of nfs)
[edit] Building
At this point, you should build your environment, if you have not yet done so. Follow the instructions in the README file in #BSP_ROOT#.
There is a seperate document for build instructions: Main-app Build Instructions
[edit] U-boot
After attaching the serial cable and starting the terminal program, power on your device. You should see in the terminal uboot output, then you'll have to interrupt the countdown within three seconds to stop the boot process.
After interrupting the countdown, you need to check that uBoot is configured correctly to be able to boot from the network. You can view the current uBoot settings with printenv.
First set the correct IP addresses:
set ipaddr 192.168.1.3 #this is the target board IP set serverip 192.168.1.2 #your host PC IP set nfs_serverip 192.168.1.2 #your host PC IP
Then the paths to retrieve kernel via TFTP and filesystem via NFS (the tftp_root is generally already ok) and to run it:
set nfs_root #BSP_ROOT#/rootfs/fs set tftp_root images set bootcmd run devkernel
Then save the settings permanently. You won't need to repeat this whole uBoot setup step again.
run update-ipstatic run update-locs
Finally let's try to get this thing rolling
boot
Please follow U-boot manuals for more details on stuff you can set.
[edit] What to do next
Once you have the development environment set up and everthing is working, you may want to burn your 'code' on to the board, you have the following options from U-boot prompt,
- generate installation images
This will properly strip binaries and create various images ready to be installed.
cd neuros-bsp make install
- update kernel
run update-kernel #this burns the kernel onto FLASH.
- update root file system
run update-cramfs #this burns the /rootfs/fs/ files onto FLASH.
Beware that there is only 0x120000 bytes (1152kB) available for the kernel and only 0x00610000 bytes (6208 kB) for the root.cramfs on the OSD. The images can be found in #BSP-ROOT/images so be sure to check their size before burning the FLASH. Neuros group page
- When you are ready set the U-boot variables so it will stop loading from TFTP and NFS but from FLASH again:
set bootcmd run cramfs_boot run update-locs
If you really (_really_) know what you are doing, you can update your U-boot as well,
run update-uboot #WARNING: if you break U-boot badly enough, you'll kill the board and only an emulator can help.
[edit] troubleshooting
[edit] Common reasons for NFS not to work:
- /etc/exports not set up correctly: <directory> <ip-address> (rw,no_root_squash,sync) - directory privileges: chmod 777 <directory> - NFS server not running: chkconfig --list | grep nfs chkconfig nfs --level 2345 on service nfs start (fc only) - Firewall. It is not sufficent to poke holes in the firewall for NFS because during the initial mount, the RPC port mapper can assign ports most anywhere. You have to disable the firewall OR disable the port mapper by using -o nolock in the mount command - Kernel is not configured properly: CONFIG_NFS_FS=y CONFIG_NFS_V3=y - Plus, for root mount: CONFIG_IP_PNP=y CONFIG_IP_PNP_RARP=y (probably) - mount command: mount -t nfs -o nolock <ip-adress>:<directory> <mount point>
The resolve.conf problem can be resolv.conf problem can be resolved in a couple of ways:
- replace /etc/resolv.conf with a link to /var/etc/resolv.conf and mount a ramdisk at /var - Use NFS root mount -- why not just NFS mount the whole filesystem so that everything is writable. You should just need to change the linux command line to something like: root=/dev/nfs nfsroot=<-host-ip-address>:<directory> rw ip=<target-ip-address>:<host-ip-address>::255.255.255.0:<target-name>
Last resort restore-to-factory settings:
With your OSD connected to ethernet and BSP built, run:
run update-defenv
This will restore the factory-default uBoot environment from the file included in the BSP checkout. Use this procedure if your kernel command line (show at about line 17 during kernel boot) gets corrupted for some reason, or you accidentally overwrite something in your environment with an update-<foo> or saveenv command.
[edit] TFTP
TFTP is far to simple to cause any real problems. But when you encounter some errors be sure the permissions are set correctly on the shared directories and that the path is correct. Sometimes the tftp path should be set to /images.
[edit] Serial woes
- If you are having trouble with your serial connection, make sure your config is set correctly, HW and SW flow control must be off for example.
- Also, Joshmalone has pointed out that not all USB/Serial often have issues. See Aug 28 2006 IRC logs for troubleshooting discussion on this.
- There are also problems reported with serial-PCI cards. They probably have hardware flowcontrol which causes problems seeing output from U-Boot. However, when U-boot finished loading normal output can be seen. Try an onboard serial port. Neuros group page
This wiki is user updated and the information here cannot be considered official Neuros communication
