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ARM Beagleboard: Difference between revisions
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This is a tutorial on bare-metal [OS] development on the Texas Instruments BeagleBoard. This tutorial is written specifically for the BeagleBoard-xM Rev C because the author has no other hardware to test on.
Experience in Linux/
=== Materials ===
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If you get 'Permission Denied' '''do NOT become root!''' This is unnecessary. Instead do:
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sudo adduser <user> dialout
</syntaxhighlight>
This will let your user use serial ports without needing root.
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===Testing the BeagleBoard===
Follow the guide here http://elinux.org/BeagleBoardDebian#Debian_armhf_port to install the Debian armhf image to a
Connect the BeagleBoard up via serial, and make sure Minicom is running (on your PC). Put the
You should get some meaningful output. Unplug your BeagleBoard when you are done with it.
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Append:
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deb http://www.emdebian.org/debian/ squeeze main
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to your /etc/apt/sources.list, changing 'squeeze' for your version of Debian - I'm running wheezy, for example.
now run:
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sudo aptitude update
sudo aptitude install gcc-4.4-arm-linux-gnueabi # check this! it might be an older version for non-wheezy...
</syntaxhighlight>
That will install a C compiler, and also install Binutils, which for this tutorial is really all we need, but you may later wish to write your code in C.
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Take note of what it does. It's pretty simple. Refer to docs if necessary.
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/* rammap */
MEMORY
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.text : { *(.text*) } > ram
}
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===Makefile===
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This is the basic makefile I use. It's similar to the one on the stackoverflow link.
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ARMGNU = arm-linux-gnueabi
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$(ARMGNU)-objcopy boot.elf -O srec boot.srec
$(ARMGNU)-objcopy boot.elf -O binary boot.bin
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===Assembly!===
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====boot.asm====
<tt><
#UART base locations from the TRM
.equ UART1.BASE, 0x4806A000
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# (branch (jump, JMP) to _hang)
# b _hang
</
==='Compiling' it===
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==Executing code on the device==
Remember that
===Introduction to u-boot===
Reset your
You should see:
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U-Boot 2011.03-rc1-00000-g9a3cc57-dirty (Apr 04 2011 - 12:36:16)
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Die ID #2e7000029ff80000016842c813020023
Hit any key to stop autoboot: 3
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Hit a key. Before Linux loads.
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OMAP3 beagleboard.org #
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Whee, a u-boot prompt.
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===Loading code===
Now it's time to load our code into RAM. To do this, we will use 'loady' and the y-modem protocol. We can do all this from
Just type 'loady'. Don't worry about being fast on your first go, you'll miss it anyway.
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OMAP3 beagleboard.org # loady
## Ready for binary (ymodem) download to 0x80200000 at 115200 bps...
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Now hit Ctrl+A. A bar will appear at the bottom.
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Ctrl+C out of the ymodem transfer window if nothing happens.
Reset your
Be patient, ymodem can take a few seconds to 'sync'.
After the file is loaded into RAM,
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READY: Press any key.
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and
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Cm - CRC mode, 9(SOH)/0(STX)/0(CAN) packets, 3 retries
## Total Size = 0x00000350 = 848 Bytes
OMAP3 beagleboard.org #
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is printed (my file is bigger... don't worry about that), we just have to execute the code in memory!
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Execution is started from an address with 'go'. Our _start address is 0x80200000. So, we type:
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OMAP3 beagleboard.org # go 0x80200000
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and we should get:
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## Starting application at 0x80200000 ...
!
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If you get that, congratulations! You've just written an 'Operating' System (;)) for the
==What to do now==
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