Saturday, November 5, 2011
Tuesday, November 1, 2011
Tuesday, October 18, 2011
I had quite a struggle getting all three of the UARTs to work under linaro on my IGEPv2. I was originally using linaro-media-create to make my microSD card image. The problem is that this seems to use the linaro kernel, rather than the IGEP kernel. As such, I would recommend first following the steps on my previous post to get the IGEP kernel, with a linaro head on it. This will make getting all of the peripherals to work much easier.
Specifically, here is what I did to get UART 1, 2 and 3 working:
Add the following line to igep.ini. For a distribution running off an SD card, this is found in the 'boot' partition of the card.
This stops UART 1 being use for RS485 and makes it available to you on J960 at RS232 instead. Note that what is happening here, is that you are disabling RS485 converter, so the RS232 port will looking like it sort of works without it, but only in one direction.
For me, UART1 did not work after the following change, so I also had to follow the instructions in the hardware manual and execute the following commands from within the loaded operating system.
For me, the 'none' was already mounted, but it can't hurt to run it again.
Note that the above line 'sudo su' makes you the root user. To get back to being yourself, use 'su USERNAME', where USERNAME is the user you were logged on as.
Add the following lines to igep.ini.
This enables UART 2 over J990.
Comment out the following line in igep.ini by placing a semicolon before it.
This disables the serial debug output over UART3 on J960, and makes it available for use by you. This may not be needed, depending on which rootfs you are using. Try joining TX and RX together (pin 2 and 3 on J960). Then open /dev/ttyS2 (say using minicom) and copy and paste a big chunk of data into it. If the screen goes crazy, it is because you are not the only one using UART2, so you have to comment out the above line.
You should now have:
UART 1 over pin 8/9 of J960 at RS232 levels
UART 2 over pin 6/8 of J990 at 1V8 CMOS levels (DO NOT EXPOSE TO ABOVE 1V8!)
UART 3 over pin 2/3 of J960 at RS232 levels
Download and unpack the latest version of rtklib, 2.4.1 as at October 2011
Install the required C compiler and Linear Algebra packs
Find out which /dev/ directory your micro SD card is connected to:
Open a terminal window and clear your dmesg using:
Now insert a new microsd card in your PC and then check your dmesg:
You should see something like this:
From now on, whenever you see 'mmcblk0' replace it with whatever your output above was . Mine was sdb, and I have replaced it in the following sections. Note that once we make them, partition 1 and partition 2 are
mmcblkp1 <=> sdb1 <=> sdc1
mmcblkp2 <=> sdb2 <=> sdc2
etc, where these appear.
Ensure all in your microsd card it's erased:
We will use the gparted program for create the partitions, if you don't have this program installed then you must install it with this command:
When the install procedure ends you can call the program from your system tools menu or directly using a terminal console using 'sudo gparted'.
Create the MSDOS Partition Table
The next step it's create the msdos table partition for it you should click in the "Device" menu and then in the "Create Partition Table" option.
Check the default option it's create a msdos partition table.
After that you can Apply.
The Next step it's create the partitions for it you should go to the partition menu and select the "New" option then the application.
We will configure the partition as:
§ Primary Partition
§ Format: FAT32
§ Size: 100 MegaBytes
§ Label: Boot
§ Align to: cylinder
We must "add" the partition.
It is recommended to apply changes now or you might get an error later.
The Next step it's create the root file system partition.
First you should select the unallocated partition area and then you should go to the partition menu and select the "New" option.
We will configure the rootfs partition as:
§ Primary Partition
§ Format: EXT4
§ Size: All the Rest
§ Label: Rootfs
At end we will click on "Add" button.
Click on apply button in the main menu after that gparted show a window to confirm all operations
We should click on apply button.
Now we can see all partitions and configurations done in the main gparted window
Select "Boot flag" for the boot partition
Now we must select the boot flag for the first partition for it we use the right mouse button over the boot partition and select "Manage Flags" option
Now we have the microsd prepared for copy the boot files
Select the boot partition and mount it in your host.
Enviroment Ubuntu 10.10
Enviroment Ubuntu 10.04
Setup the board settings
You should execute contrib/signGP for sign the xloader.
Copy the created x-loader.bin.ift into the boot partition and rename x-loader.bin.ift to MLO as follows. Note first you must mount the boot partition by right clicking on 'Places'-> 'boot' and selecting 'mount.'
Now we're ready for test the board boots from the microsd card.
X-Loader boot test
We will eject the boot and rootfs partitions from our Host PC, this step it's a lot important due the Linux must sync all changes before eject the microsd card.
We will insert our microSD card into the IGEP board, connect the serial debug cable and open the serial terminal
Power UP the board and you should see something similar to this put out over the serial console
Configure the IGEP-X-Loader
As mentioned earlier, the x-loader is the first file called by the processor. It is then responsible for calling the kernel. In order to control what start-up parameters the kernel is given, we use a file called igep.ini. You can use a file like this:
Create a new file into the boot partition named igep.ini with these content in it and save the file. I will explain some of the lines in this file in a later post.
Download the latest stable version sources and follow next steps:
A generic configuration is provided for all IGEP machines, and can be used as the default by
Create the Rootfs mount point
Go to /media directory and create one sub-folder called "binary"
Mount the rootfs partition using the 'binary' directory
The rootfs (also called the 'head' I think) is what we see of the operating system. In this tutorial I will use a rootfs made by linaro. There are several options available from
ALIP - a very basic desktop including applications for internet browsing (ubuntu 10.10 based)
Netbook - has a few more features and is a bit bigger/slower but comes with a bunch of useful programs pre-isntalled
Plasma - the biggest of the options, it also has the nicest features and best looking desktop.
Headless - doesn't use a screen. To access it, you have to use a remote console via a serial link.
Untar the rootfs package
Make sure "linaro-m-headless-tar-20101108-2.tar.gz" or whichever linaro you have decided on is inside the /media directory and untar it using:
Install the kernel modules
Now you should install your kernel modules inside your root file system.
Install the kernel Image
Just copy the zImage inside your boot partition, remember before that you must mount your mmc boot partition.
After that you can unmount the boot & rootfs partitions. You may need to umount sdb2 twice if you get an error the first time
Now we're ready for test our new microsd card
Put your new SD card into your IGEP and power it up, with a monitor plugged into you DVI port. A red LED on your IGEPv2 should come on (this is the xloader doing its thing). This should then turn to a solid green LED as the kernel loads. Soon after this, some lines of debug info should start showing up on your screen, then a short pause and finally your working rootfs should load (i.e. your computer is now on!).