ECE497 Project: Multiple Partitions via U-boot - Revision history

Yoder: Moved to Winter1112 category

2012-07-16T13:55:23Z

Moved to Winter1112 category

Yoder: /* Grade */ Added

2012-02-24T20:17:44Z

‎Grade: Added

Mac at 23:33, 20 February 2012

2012-02-20T23:33:00Z

Yuhasmj: /* Partition Script */

2012-02-20T06:52:17Z

‎Partition Script

Yuhasmj: /* I Have Multiple Partitions, Now What? */

2012-02-20T06:50:40Z

‎I Have Multiple Partitions, Now What?

Yuhasmj: /* The Multi-Partition Creator Script */

2012-02-20T06:44:07Z

‎The Multi-Partition Creator Script

Yuhasmj at 20:01, 19 February 2012

2012-02-19T20:01:45Z

Yuhasmj: /* Theory of Operation */

2012-02-19T19:55:25Z

‎Theory of Operation

Yuhasmj: /* U-boot Modifications */

2012-02-19T19:51:51Z

‎U-boot Modifications

Yuhasmj: /* U-boot Modifications */

2012-02-19T19:32:48Z

‎U-boot Modifications

← Older revision		Revision as of 13:55, 16 July 2012
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−	[[Category:~~ECE497~~]]	+	[[Category:ECE497Winter1112]]

	Team members: [[user:Yuhasmj\|Michael J. Yuhas]], [[user:mac\|Jack Ma]]		Team members: [[user:Yuhasmj\|Michael J. Yuhas]], [[user:mac\|Jack Ma]]

← Older revision		Revision as of 20:17, 24 February 2012
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	Team members: [[user:Yuhasmj\|Michael J. Yuhas]], [[user:mac\|Jack Ma]]		Team members: [[user:Yuhasmj\|Michael J. Yuhas]], [[user:mac\|Jack Ma]]
		+
		+	== Grade ==
		+
		+	Nice detailed report. Nice project. I haven't run it on my Beagle yet, but I want to. Good Job.
		+
		+	Project: 95
		+	Wiki: 95
		+	'''Total:''' 95

	== Executive Summary ==		== Executive Summary ==

@@ Line 155: / Line 155: @@
 This process takes long time to perform by hand, so we thought it would be neat to create a user command that would add another layer of abstraction.
-After some research, we found instructions on how to create a command in U-boot, but the article was written entirely in Chinese.  Luckily we had Jack in our group.  The following is a high level description of the process of adding a user defined command to U-boot.
+After some research, we found instructions on how to create a command in U-boot, but the article was written entirely in Chinese. The webpage which gave us insight into how to add a command to u-boot is [http://hi.baidu.com/282409975/blog/item/527f5ce996cf77ddd539c9b9.html http://hi.baidu.com/282409975/blog/item/527f5ce996cf77ddd539c9b9.html]. From here, we further explored how we could invoke a command within command. Luckily we had Jack in our group.  The following is a high level description of the process of adding a user defined command to U-boot.
 First, you must add your command.c file to the common folder using the naming scheme, cmd_<your command name>.c.  You must also include the following headers in your file:

@@ Line 135: / Line 135: @@
 Initially we tried to manually create a multi-partitioned sd card from which to boot, however, we soon ran into many problems.  At first, we manually partitioned the disk into a 128MB boot sector and divided the rest of the space evenly between two ext2 partitions.  We then copied files from a working sd card to populate the partitions.  The initial problem was that we performed did not perform a sudo copy and that some files were left behind, but when we tried this strategy on previously unformatted cards, we discovered that there was something else wrong with this method.
-Before we could continue, we had to learn little bit about how static memory is addressed in a hard disk or any other form of longterm storage.  It turns out that data is still allocated into sectors, cylinders and heads, just like in the early days of computing.  An i depth description can be found [ here].  We learned that for a FAT32 file system, there are 512 bytes in each sector, and 63 sectors in each head.  There is a maximum number of 255 permitted heads for one device.  This means that to deal with larger file systems, the number of cylinders must change.  We played around with the command line tool fdisk to get an idea of partition a sd card with this format.  Because the process was fairly complex, we decided to write a script to do our job for us.
+Before we could continue, we had to learn little bit about how static memory is addressed in a hard disk or any other form of longterm storage.  It turns out that data is still allocated into sectors, cylinders and heads, just like in the early days of computing.  An in depth description can be found [http://en.wikipedia.org/wiki/Cylinder-head-sector here].  We learned that for a FAT32 file system, there are 512 bytes in each sector, and 63 sectors in each head.  There is a maximum number of 255 permitted heads for one device.  This means that to deal with larger file systems, the number of cylinders must change.  We played around with the command line tool fdisk to get an idea of partition a sd card with this format.  Because the process was fairly complex, we decided to write a script to do our job for us.
 Rather than reinventing the wheel, we found a [http://www.slimlogic.co.uk/2011/05/omap3-sd-booting/ website] who had already written a script to partition an sd card for a single partition of Angstrom Linux.  We used this script as the basis for our creation which will create four partitions on a single sd card.  The first partition is used for boot, meaning the remaining three partitions can be used as the root file system in an OS.

@@ Line 107: / Line 107: @@
 === I Have Multiple Partitions, Now What? ===
-Now put the sd card in your beagle board and fire it up.  Be sure to plug a cable from the serial port on the beagle board to some kind of connection on the computer.  Instructions to do this can be found [ here].
+Now put the sd card in your beagle board and fire it up.  Be sure to plug a cable from the serial port on the beagle board to some kind of connection on the computer.  Instructions to do this can be found [http://elinux.org/ECE497_Tips_and_Tricks#Accessing_the_Beagle_via_the_Serial_Port here].
 Once byobu is opened, and you have U-boot running, enter the following command:

@@ Line 103: / Line 103: @@
 </pre>
-Your drive now has four partitions on it, three of which can serve as a root file system for linux.  The first partition is FAT32 and will serve as the boot sector where U-boot lives.  Now, copy your MLO, u-boot.bin, u-boot.img, and uimage to the boot sector of your mmc card.  Also, obtain a copy of the root file system for Angstrom.  Due to the the size limitations of uploads, we cannot provide this, but if you follow the instruction [ here] to build a normal Angstrom MMC card and then sudo copy all the files in Narcissus-rootfs to your computer, you will have a bootable root file system.
+Your drive now has four partitions on it, three of which can serve as a root file system for linux.  The first partition is FAT32 and will serve as the boot sector where U-boot lives.  Now, copy your MLO, u-boot.bin, u-boot.img, and uimage to the boot sector of your mmc card.  Also, obtain a copy of the root file system for Angstrom.  Due to the the size limitations of uploads, we cannot provide this, but if you follow the instruction [http://elinux.org/EBC_Exercise_00_Installing_Angstrom_on_SD here] to build a normal Angstrom MMC card and then sudo copy all the files in Narcissus-rootfs to your computer, you will have a bootable root file system.
-−
 === I Have Multiple Partitions, Now What? ===

← Older revision		Revision as of 20:01, 19 February 2012
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	== Conclusions ==		== Conclusions ==

−	~~Not yet available~~.	+	We found this project very interesting because it gave us an in depth look into the way a boot-loader works. We saw how to add commands, and learned how the boot-loader actually determines what to do when a user enters a command. We also learned about the way memory is addressed in long term storage and learned about how it affects different file system schemes.
		+
		+	We feel that future additions to this project could include the following:
		+
		+	1.) The ability to boot from USB (We tried to look into this, but did not make much progress)
		+
		+	2.) The usage of the user button to select a boot partition at start-up
		+
		+	3.) The ability to boot into different operating systems. (Our code should support this, but we did not have time to test it).

← Older revision		Revision as of 19:55, 19 February 2012
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	To call other commands from the U-boot, we discovered the run_command("string to run", flag); command to let us access pre-written commands. We also discovered that although stdio.c was not in the toolchain, we could use sprintf to parse variables into strings. Theses commands gave us the tools we needed to take the above command list and automate them under a single unified user command.		To call other commands from the U-boot, we discovered the run_command("string to run", flag); command to let us access pre-written commands. We also discovered that although stdio.c was not in the toolchain, we could use sprintf to parse variables into strings. Theses commands gave us the tools we needed to take the above command list and automate them under a single unified user command.
		+
		+	=== Difficulties Using the Git Repository ===
		+
		+	The installation section describes some steps that must be taken if the git repository that someone pulls is bad. We discovered that a number of .depend files are created every time a user runs make on U-boot, and if this user pushes there directory to git, the .depends will cause problems for users with other machine configurations. To solve this, we discovered an includes file in git that would allow us to include and exclude certain files while do a git push. We believe we have solved this problem, but just in case, the work-around is located above.

	== Work Breakdown ==		== Work Breakdown ==

← Older revision		Revision as of 19:51, 19 February 2012
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	After some research, we found instructions on how to create a command in U-boot, but the article was written entirely in Chinese. Luckily we had Jack in our group. The following is a high level description of the process of adding a user defined command to U-boot.		After some research, we found instructions on how to create a command in U-boot, but the article was written entirely in Chinese. Luckily we had Jack in our group. The following is a high level description of the process of adding a user defined command to U-boot.
		+
		+	First, you must add your command.c file to the common folder using the naming scheme, cmd_<your command name>.c. You must also include the following headers in your file:
		+
		+	<pre>
		+	#include <common.h>
		+	#include <config.h> //CONFIG_CMD_JACK
		+	#include <command.h> //U_BOOT_CMD
		+	</pre>
		+
		+	The common.h loads libraries native to all U-boot source code. The command.h and config.h load globals that commands will need to be recognized by U-boot. It is important to note that stdio.h and stdlib.h are not supported by the tool chain we will be using.
		+
		+	In addition, we must define our command in the Makefile, the header for the Omap3 Beagle Board, and the config_cmd_all.h that contains a list of all commands.
		+
		+	<pre>
		+	./common/Makefile:COBJS-$(CONFIG_CMD_JACK) += cmd_jack.o
		+	./include/configs/omap3_beagle.h:#define CONFIG_CMD_JACK
		+	./include/config_cmd_all.h:#define CONFIG_CMD_JACK
		+	</pre>
		+
		+	We named our command jack and created a cmd_jack.c file in the common directory. In the cmd_jack.c file, we needed to create some functions to execute when the command is called. The do_jack() function is the main function that will be executed every time the command is called. We also needed to add a call to U_BOOT_CMD(jack,0,1,do_jack,"Test Program.\n"); that would run every time somebody ran help on the jack command.
		+
		+	To call other commands from the U-boot, we discovered the run_command("string to run", flag); command to let us access pre-written commands. We also discovered that although stdio.c was not in the toolchain, we could use sprintf to parse variables into strings. Theses commands gave us the tools we needed to take the above command list and automate them under a single unified user command.

	== Work Breakdown ==		== Work Breakdown ==

@@ Line 146: / Line 146: @@
 <pre>
 U-boot # mmc part
 </pre>
 == Work Breakdown ==