Can U-Boot boot scripts have comments? - comments

I'm writing a U-Boot boot script, and I'd like to clarify why a specific address is used exactly. However, I've not been able to find any documentation on how to write comments in U-Boot boot scripts, or if this is possible at all. Is it possible for U-Boot boot scripts to have comments, and if so, how do I write comments in them?

Related

How can a kernel written in Go boot?

It seems most kernels are written in C. But yesterday on Hackernews there was a project called the Biscuit research OS.
It claims to be written in Go although there are some assembly and C code in there. So my question is. How does something like this work where the system can boot but it's written in Go?
If you look around you will find the paper(https://pdos.csail.mit.edu/papers/biscuit.pdf) they used a layer that can support Go runtime over which the Biscuit runs
It contains a lot more information in detail, I suggest you should take a look into it.

Remote Debugging Hosted Lua

I am using Lua 5.3, hosting it in a C++ application. The C++ application provides various functions to a running Lua script. I would like to allow users to debug their Lua, while it is running in my application. I believe this is possible, but I can not find any recent information on doing this, only for older versions of Lua and this does not seem to work.
Can anyone please help me to get debugging a Lua script running under my application up and running? Any help would be greatly appreciated.
Thank you!
The easiest way that I know of is to use ZeroBrane's remote debugging capabilities. Their document explains it pretty nicely, but for the sake of self-containment:
Set your embedded Lua's path/cpath to zerobrane's stuff, or copy the mobdebug.lua file to your sources.
Add require('mobdebug').start() to the beginning of your code
You should be able to debug now. After you start your program, breakpoints set in the Lua sources should get hit.
This approach works best if you use ZB to edit your Lua files, which implies using a different editor for the C++ part. I found this to work reasonably well in practice, though.

Linux on Dragonboard APQ8074

I have a DragonBoard APQ8074 with SnapDragon 800. I am able to successfully build Android and run some OpenCL related apps on this.
I am currently trying to build a linux kernel and load either Ubuntu or Fedora on this board.
It wouldbe really helpful if anyone could point me to suitable posts or guides.
I did look into Freedreno, it is really a good starting point, but i am still unable to understand the part of initrd/ramdisk img file.
Also the bootloader (similar to u-boot i assume), i am not clear which parts of it i need to update, if at all necessary.
Thanks in advance.
regard,
Anup.
This might help http://whiteboard.ping.se/Android/Android. There's a few sections there that might be handy. I also found this other article that helped me understand intrd and intramfs a bit better if that helps. http://www.linux.com/learn/linux-career-center/114923-the-kernel-newbie-corner-qinitrdq-and-qinitramfsq-some-unfinished-business

UEFI BootLoader

I am looking at developing a simple (to start with) UEFI Boot loader to load a ELF image, and was wondering if anyone had a good entry point into maybe any existing projects, or examples that I can use to get started out with.
In addition I was wondering if any one had any experience in getting virtual box to run an EFI application. I have set up a VM with EFI mother board but can seam to create an EFI System Partition for it to load out of (without using an OS), all I can achieve is the UEFI command line.
You might try taking a look at the GRUB or elilo source code. These are also good because they support loading ELF images. You might also look to the EDK2, there is a lot of good code there, and it's easy to build EFI executable images with it.
When referencing the UEFI, I also like to use Phoenix's wiki. I find the boot services entry to be especially useful.
Hope this helps at least a little!
I recently became interested in bootloaders too. I'm still a newbie in this field, but I found this interesting step-by-step tutorial to code a "Hello World" bootloader. Hope it gives you or anyone else with the same question a starting point for developing your bootloader.
GRUB installation on UEFI is possible by means of grub-mkimage. ELF binaries are known to be similarly masqueraded as complying UEFI's PE32+ requirement. If some C developers will refactor the code as done by https://www.kernel.org/doc/Documentation/efi-stub.txt and then generalize mkimage's that code as a separate tool for the sake of multibooters without PE32+ kernel loaders for every OS...
Just imagine
ld -b input-format -o <output>.efi --oformat=output-format objfile ...

Customizing linux kernel for new board

I'm porting/customizing linux kernel for our board. I will base on atmel evolution board configuration, and I need to overwrite some startup routines and add our drivers.
Is there any document, link, forum where I can get information how to make it in Linux way ?
Which files can I overwrite, and which shall I create from scratch ?
Is this a Board Support Package question ?
Thank you
I doubt that there is short and simple answer to your question. To accomplish this task you should more or less good understand Linux as distribution (kernel + boot scripts + user space software) work together and how make them be a friends.
I could recommend you book, which I found extremely useful as embedded Linux engineer: Embedded Linux Primer: A Practical Real-World Approach (2nd Edition) I am quite confident it will answer most of your questions.
I think that's it. Short, nice, fresh:
http://free-electrons.com/blog/elce-2012-slides-porting-linux-to-new-arm-soc/

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