* [U-Boot] Sources for MLO on BeagleBone Black? [not found] <CAJoPetqS2rW5+UaObwd-2W3=zV_ZJy-UZs0BBHsijZ0QdHuONA@mail.gmail.com> @ 2013-12-04 14:08 ` Satz Klauer 2013-12-04 14:58 ` Tom Rini 0 siblings, 1 reply; 7+ messages in thread From: Satz Klauer @ 2013-12-04 14:08 UTC (permalink / raw) To: u-boot Hi, I'm looking for the sources of the MLO bootloader that is used on BeagleBone Black by default. A posting within TIs webboard pointed me to this location but ... where are the sources? While checking the GIT repositiory I could not find anything that looked like "MLO" or "BeagleBone Black". Thanks! ^ permalink raw reply [flat|nested] 7+ messages in thread
* [U-Boot] Sources for MLO on BeagleBone Black? 2013-12-04 14:08 ` [U-Boot] Sources for MLO on BeagleBone Black? Satz Klauer @ 2013-12-04 14:58 ` Tom Rini 2013-12-04 20:34 ` Satz Klauer 0 siblings, 1 reply; 7+ messages in thread From: Tom Rini @ 2013-12-04 14:58 UTC (permalink / raw) To: u-boot On Wed, Dec 04, 2013 at 03:08:43PM +0100, Satz Klauer wrote: > Hi, > > I'm looking for the sources of the MLO bootloader that is used on > BeagleBone Black by default. A posting within TIs webboard pointed me > to this location but ... where are the sources? While checking the GIT > repositiory I could not find anything that looked like "MLO" or > "BeagleBone Black". When you build for am335x_evm you get both u-boot.img and MLO files that work on a number of boards from TI that use the am335x chip, including Beaglebone Black. -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: <http://lists.denx.de/pipermail/u-boot/attachments/20131204/2558aa7c/attachment.pgp> ^ permalink raw reply [flat|nested] 7+ messages in thread
* [U-Boot] Sources for MLO on BeagleBone Black? 2013-12-04 14:58 ` Tom Rini @ 2013-12-04 20:34 ` Satz Klauer 2013-12-04 20:40 ` Robert Nelson ` (2 more replies) 0 siblings, 3 replies; 7+ messages in thread From: Satz Klauer @ 2013-12-04 20:34 UTC (permalink / raw) To: u-boot Hi Tom, point is, I want to change some functionality of bootloader - thus I want to know where it is built from. It is nice when MLO file appears automagically but in my special case I like to know where it comes from exaclty. Thanks :-) On Wed, Dec 4, 2013 at 3:58 PM, Tom Rini <trini@ti.com> wrote: > On Wed, Dec 04, 2013 at 03:08:43PM +0100, Satz Klauer wrote: > >> Hi, >> >> I'm looking for the sources of the MLO bootloader that is used on >> BeagleBone Black by default. A posting within TIs webboard pointed me >> to this location but ... where are the sources? While checking the GIT >> repositiory I could not find anything that looked like "MLO" or >> "BeagleBone Black". > > When you build for am335x_evm you get both u-boot.img and MLO files that > work on a number of boards from TI that use the am335x chip, including > Beaglebone Black. > > -- > Tom ^ permalink raw reply [flat|nested] 7+ messages in thread
* [U-Boot] Sources for MLO on BeagleBone Black? 2013-12-04 20:34 ` Satz Klauer @ 2013-12-04 20:40 ` Robert Nelson 2013-12-04 20:48 ` Tom Rini 2013-12-05 5:08 ` Abraham V. 2 siblings, 0 replies; 7+ messages in thread From: Robert Nelson @ 2013-12-04 20:40 UTC (permalink / raw) To: u-boot On Wed, Dec 4, 2013 at 2:34 PM, Satz Klauer <satzklauer@googlemail.com> wrote: > Hi Tom, > > point is, I want to change some functionality of bootloader - thus I > want to know where it is built from. It is nice when MLO file appears > automagically but in my special case I like to know where it comes > from exaclty. http://git.denx.de/?p=u-boot.git;a=blob;f=arch/arm/cpu/armv7/am33xx/config.mk#l7 Everything built inside "CONFIG_SPL_BUILD" for the particular TI/OMAP based target.. Regards, -- Robert Nelson http://www.rcn-ee.com/ ^ permalink raw reply [flat|nested] 7+ messages in thread
* [U-Boot] Sources for MLO on BeagleBone Black? 2013-12-04 20:34 ` Satz Klauer 2013-12-04 20:40 ` Robert Nelson @ 2013-12-04 20:48 ` Tom Rini 2013-12-05 5:08 ` Abraham V. 2 siblings, 0 replies; 7+ messages in thread From: Tom Rini @ 2013-12-04 20:48 UTC (permalink / raw) To: u-boot -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 12/04/2013 03:34 PM, Satz Klauer wrote: > Hi Tom, > > point is, I want to change some functionality of bootloader - thus > I want to know where it is built from. It is nice when MLO file > appears automagically but in my special case I like to know where > it comes from exaclty. Well, if you use out of tree building (O=/tmp/build) you can see each file that was built for both u-boot and MLO (under the spl directory), based on the config file (include/configs/am335x_evm.h). - -- Tom -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJSn5UsAAoJENk4IS6UOR1WJt0QALAWE0N9BDAAJdw1IUVd3Ipq /RP2jomagcuQU2FOKJVDA/uiXgxsp6dn8jWwUSHevkMr4npYB6mWO3F7PO2gLMXh CUXffwIOQ7NuU0mmbOpD7nyqHf78mWXHl5ZxJMeXq6YejWb5vr67gZIFOZQQL4yD W4dGDjirMtCTrNGBFZn9RSWwoBsTSt9UGRE95MA3BhQtFbQ3OVefQ3AqmqzQJ+xn Eyj3Cl1Nuju6vIVgchZLkkQgNP2SSNy6OBa8hXTwWXqYp8flFMKkkNfPuyYXil+F NU1n7lHAwRJ5s/AT0euzsPLOilu6CG4RhYaXYU/g9ToctKk3S2g+FtAbpUU6iFph GiE5ZcU1OkPa0sGJE9M+QxqXbwXge/QkmPL4PTFAh1OXYKFcLM/jVxhUPdEKWcV+ K/Ld+vx5tXHvK4tOZTOg/jZJsdSQtDFGSQj9WoyDhq5rOExXwhLmFd4PRLTQQJpn 5nTuoVE2eVXdExHVBCrLphHfGPp5bnsFFX7ITEAVTDNu5A7Z0OBe6RUZU3LQx/6q 34ZU0QOiG0xbNRK4ePObvw+PGqrmVhXpLkboAs+o1STLemZazklq1tInGxRpAXbc MeBq0cDfyKnRjKGLwCgUZpOu6I5XdY+m10rLLJo+uHaQYc91hHq+EXBBsIXyfDu+ Zo3GZ8wtFPzmhvCE4k5/ =KzJB -----END PGP SIGNATURE----- ^ permalink raw reply [flat|nested] 7+ messages in thread
* [U-Boot] Sources for MLO on BeagleBone Black? 2013-12-04 20:34 ` Satz Klauer 2013-12-04 20:40 ` Robert Nelson 2013-12-04 20:48 ` Tom Rini @ 2013-12-05 5:08 ` Abraham V. 2013-12-05 6:26 ` Satz Klauer 2 siblings, 1 reply; 7+ messages in thread From: Abraham V. @ 2013-12-05 5:08 UTC (permalink / raw) To: u-boot Hello Satz, A bit of history - until a few years ago, the u-boot project only produced a single binary output (u-boot.bin or u-boot.img) that you loaded for your board. The resulting binary usually comes to about 200 - 250kB (approx). Then Texas Instruments began manufacturing the OMAP line of SOC's that had some static-RAM built into the chip. The idea was that we could have some initialization code to setup the bare environment before doing other things. A limitation was that the SRAM had a capacity of just a few kB (think less than 50kB, I don't remember what the exact number is). So, (I presume) someone from TI make a fork of the u-boot code base to produce a "minimal" boot-loader called X-loader. The resulting binary came to about 25kB or so. The boot sequence thus went like this; ROM code (we can't edit this) -> X-loader (in SRAM) -> u-boot (in DDR RAM) -> Linux system. (for details see here: http://omappedia.org/wiki/Bootloader_Project) Normal DDR ram doesn't "just work". You need something to initialize the clocks (and possibly power?), before the processor can make use of it. This is was X-loader did. Eventually, other manufacturers (Samsung? nVidia? not sure if Freescale uses it....) picked up on the idea of having SRAM in their SOC's for initialization purposes and instead of maintaining two separate code-bases, an idea cropped up to merge X-loader back into the u-boot source. This was eventually done and that's where we are today. Now, to "edit the bootloader", Satz, you'll want to understand the build process. The MLO file does not "magically" appear. It is actually built on your computer right after u-boot gets built. In a nutshell, when you run, > make omap3_beaglebone_config (I forgot what the actual config is) A few configuration files get created. This is in preparation for the next step, which is; > make The above is an instruction to the uboot build system to scan the configuration files and build whatever system was specified. In the case of beagleboneblack (and omap processors) this happens in 2 different stages. First, the entire source tree is scanned/compiled to create the "u-boot.bin" (or u-boot.img) file. Then the build system re-starts the scan to compile the MLO file. If you browse the source, you'll see code like "#if SPL_CONFIG" (or similar). These are the sections that instruct the build system to create the MLO file. Hope it answers your question? :) Drinking coffee, Abraham On Thu, Dec 5, 2013 at 2:04 AM, Satz Klauer <satzklauer@googlemail.com> wrote: > Hi Tom, > > point is, I want to change some functionality of bootloader - thus I > want to know where it is built from. It is nice when MLO file appears > automagically but in my special case I like to know where it comes > from exaclty. > > Thanks :-) > > > On Wed, Dec 4, 2013 at 3:58 PM, Tom Rini <trini@ti.com> wrote: >> On Wed, Dec 04, 2013 at 03:08:43PM +0100, Satz Klauer wrote: >> >>> Hi, >>> >>> I'm looking for the sources of the MLO bootloader that is used on >>> BeagleBone Black by default. A posting within TIs webboard pointed me >>> to this location but ... where are the sources? While checking the GIT >>> repositiory I could not find anything that looked like "MLO" or >>> "BeagleBone Black". >> >> When you build for am335x_evm you get both u-boot.img and MLO files that >> work on a number of boards from TI that use the am335x chip, including >> Beaglebone Black. >> >> -- >> Tom > _______________________________________________ > U-Boot mailing list > U-Boot at lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot ^ permalink raw reply [flat|nested] 7+ messages in thread
* [U-Boot] Sources for MLO on BeagleBone Black? 2013-12-05 5:08 ` Abraham V. @ 2013-12-05 6:26 ` Satz Klauer 0 siblings, 0 replies; 7+ messages in thread From: Satz Klauer @ 2013-12-05 6:26 UTC (permalink / raw) To: u-boot On Thu, Dec 5, 2013 at 6:08 AM, Abraham V. <abraham.varricatt@vvdntech.com> wrote: > > Hope it answers your question? :) Yes, it does - thanks! > Drinking coffee, Making a cup of tea now... ^ permalink raw reply [flat|nested] 7+ messages in thread
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[not found] <CAJoPetqS2rW5+UaObwd-2W3=zV_ZJy-UZs0BBHsijZ0QdHuONA@mail.gmail.com>
2013-12-04 14:08 ` [U-Boot] Sources for MLO on BeagleBone Black? Satz Klauer
2013-12-04 14:58 ` Tom Rini
2013-12-04 20:34 ` Satz Klauer
2013-12-04 20:40 ` Robert Nelson
2013-12-04 20:48 ` Tom Rini
2013-12-05 5:08 ` Abraham V.
2013-12-05 6:26 ` Satz Klauer
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