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by jameswalmsley
Wed May 27, 2015 10:54 pm
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

Hi rofs, I've got it working again :) Although it will be about as exciting as a flashing LED. I'll port the UART driver tomorrow, and the sdcard driver on Friday. I'll then probably get the MMU code working, and start working on USB. You should be able to simply checkout the latest code: git clone ...
by jameswalmsley
Mon May 25, 2015 6:58 pm
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

Hi rofs,

I'm currently repairing BitThunder on the raspberrypi. I see there's some problems in the ARM layer for this architecture.
I'm also optimising it for the RPi 2 architecture.

I'll post back here this week when I have it working again.

James
by jameswalmsley
Fri May 22, 2015 11:56 am
Forum: Bare metal, Assembly language
Topic: Linker script nightmare -- please help!
Replies: 3
Views: 836

Re: Linker script nightmare -- please help!

Thanks for the help.
Yes its replaced with SRAM by a pre-processor.

I just solved the problem by merging the .bt.init and .bt.arch.init into a single section.
Maybe there's something weird with the section names that I don't understand.

James
by jameswalmsley
Thu May 21, 2015 5:54 pm
Forum: Bare metal, Assembly language
Topic: RTOS - which? status?
Replies: 6
Views: 3431

Re: RTOS - which? status?

I'm currently trying to revive the BitThunder port on RaspberryPi and Pi2. I'll try to update you as I get along. Since I lost spoke of BT here its advanced hugely but mostly on other platforms like Xilinx Zynq. USB is still the biggest blocker for simple bare-metal projects to integrate networking ...
by jameswalmsley
Thu May 21, 2015 5:52 pm
Forum: Bare metal, Assembly language
Topic: Linker script nightmare -- please help!
Replies: 3
Views: 836

Linker script nightmare -- please help!

Hi All, I've been suffering with a bug in a linker script for a really long time, and I have no idea how to fix it or what causes it. Here's my linker script... (cut for context, but the real thing is much longer, but simply adds more sections. ENTRY(bt_reset) _STACK_SIZE = DEFINED(_STACK_SIZE) ? _S...
by jameswalmsley
Mon Aug 12, 2013 2:41 pm
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

Hi Snigelson, nuclearwessels, Gringow,

I've now made a decent example project that you can simply clone, and also fixed some other issues.
Its available at:

https://github.com/BitThunder/example-project

James
by jameswalmsley
Mon Aug 12, 2013 12:17 pm
Forum: Bare metal, Assembly language
Topic: Announcing BitThunder (FreeRTOS based OS platform).
Replies: 9
Views: 6249

Re: Announcing BitThunder (FreeRTOS based OS platform).

Afaber, Thanks for trying. I'm going to test this out again this evening for you. I need to push a lot of work, but don't want to break the RaspberryPi example. A friend also had the same problem, which was fixed when formatting the SD-card correctly (I sent him an image of my card). Thanks James
by jameswalmsley
Mon Aug 12, 2013 12:15 pm
Forum: Bare metal, Assembly language
Topic: Announcing BitThunder (FreeRTOS based OS platform).
Replies: 9
Views: 6249

Re: Announcing BitThunder (FreeRTOS based OS platform).

Hi ali8, I am still waiting my RPi (will be here in two days) but do you have any numbers for latencies, etc? So I didn't make any hard measurements of scheduler latency, but its incredibly small. It should be the same as using a plain FreeRTOS scheduler. FreeRTOS is pretty much the standard solutio...
by jameswalmsley
Wed Jul 10, 2013 8:24 pm
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

Hi Snigelson, Gringow, Thanks for continuing to try this out. I don't have time this evening to write a patch to fix all the issues you're experiencing. However I have huge memory management patch to merge tomorrow that allows the whole thing to run in a virtual address space. Most of the errors you...
by jameswalmsley
Tue Jul 02, 2013 5:49 pm
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

Hi All,

I've fixed the linking problem for other compilers. Now I'm linking with gcc directly, and so now you just have to put in your
compiler prefix in the configuration.
# To update your repos with the makefile patch...
git pull
Thanks,

James
by jameswalmsley
Tue Jul 02, 2013 5:09 pm
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

Hi Snigelson, Thanks for trying this out. Currently the linker location is hard-coded. Actually I really want to get rid of this requirement, I think I can call gcc directly to do the linking. Do you know how to fix that? I also will make the optimisations and debug settings configurable in Kconfig....
by jameswalmsley
Mon Jul 01, 2013 7:37 pm
Forum: General programming discussion
Topic: Hospital Bed
Replies: 32
Views: 4743

Re: Hospital Bed

Sounds like your being over cautious. I just dont trust the RPi or Siri with my or anyone else's life. Siri has tried to kill before! http://newsfeed.time.com/2012/12/11/australian-police-says-apple-maps-can-be-life-threatening/ ;) In today's world, apparently warning labels are required for everyt...
by jameswalmsley
Mon Jul 01, 2013 7:36 pm
Forum: General programming discussion
Topic: Hospital Bed
Replies: 32
Views: 4743

Re: Hospital Bed

I'm struggling to find a pinout for that connector. Although it seems like a few manufacturers actually make compatible control boxes. If you could upload some pictures of the box when opened up, high-resolution of the PCB from both sides then we can easily see how it works. It should be very simple...
by jameswalmsley
Mon Jul 01, 2013 7:20 pm
Forum: General programming discussion
Topic: Hospital Bed
Replies: 32
Views: 4743

Re: Hospital Bed

Come on people, ignore the unnecessary legal fluff, anyone have answers? I'm sure someone's legal department just had their hearts stopped. Legal issues aside, its also unethical and/or immoral to assist someone with experimenting on themselves. This individual is unable to escape by themselves in ...
by jameswalmsley
Mon Jul 01, 2013 7:18 pm
Forum: General programming discussion
Topic: Hospital Bed
Replies: 32
Views: 4743

Re: Hospital Bed

I'm finding datasheets on this thing. Thanks for the images, I'll see what I can dig up.

James
by jameswalmsley
Mon Jul 01, 2013 7:12 pm
Forum: General programming discussion
Topic: Hospital Bed
Replies: 32
Views: 4743

Re: Hospital Bed

RPDom has the best advice, the rest are all spouting non-sense :P gotta have fun sometimes guys, or no-one would ever invent anything. I cant give you any definite answers, but... 1. Judging by the fact that you can pull the lines to ground, (without any bangs/sparks) and stuff actually happens. And...
by jameswalmsley
Mon Jul 01, 2013 5:53 pm
Forum: Bare metal, Assembly language
Topic: BitThunder - Todo tasks :) (Framebuffer Console)
Replies: 0
Views: 594

BitThunder - Todo tasks :) (Framebuffer Console)

Hi Everyone, I am looking to implement a framebuffer driver API in bitthunder very soon. However before I go ahead and implement it, I was wondering if anybody else wants to have a go and take the credit :) Anyone who is interested, I will make myself available on Skype in the evenings (UK) time, an...
by jameswalmsley
Mon Jul 01, 2013 5:37 pm
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

Ok I added the patch:

Code: Select all

git pull
make menuconfig
# OS Features -> Process Manager
    - Select Invert GPIO Priority.
Hope it works for you,

James
by jameswalmsley
Mon Jul 01, 2013 5:29 pm
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

Hi, I just tested this on my Pi, and I can confirm it works (much to my own surprise). Unfortunately the LED has inverted logic, and so I need to add a patch quickly to make it more interesting. In the mean time, to enable the "Alive LED" do the following: make menuconfig # OS Features -> Process Ma...
by jameswalmsley
Mon Jul 01, 2013 5:11 pm
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

Hi, Firstly thanks for trying this out and perservering with it :) Not sure what that D-BUILD thing was, I wrote my own set of build scripts and thats included in the repository. You don't need to install any extras for dbuild (it just needs python). But thats not your problem. It sounds like the pr...
by jameswalmsley
Thu Jun 27, 2013 9:24 am
Forum: Bare metal, Assembly language
Topic: About Vitrual memory
Replies: 16
Views: 4094

Re: About Vitrual memory

Hi Guys, I have just implemented MMU support in BitThunder. I'll be pushing it to github very soon. I'll also try to write a more comprehensive guide on how I do the ioremapping etc. For now I've made a quick overview here: http://bitthunder.org/memory/2013/07/19/mmu-support.html Its very similar to...
by jameswalmsley
Thu Jun 27, 2013 9:19 am
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Re: Building BitThunder for the RaspberryPi

I also wrote this up on the bitthunder website:
http://bitthunder.org/docs/quick-start/
by jameswalmsley
Thu Jun 27, 2013 8:33 am
Forum: Bare metal, Assembly language
Topic: Easter algorithm (Knuth)
Replies: 2
Views: 1245

Re: Easter algorithm (Knuth)

Wow, that's a really nice guide and tutorial for learning about assembly, and basic optimisations.
I saw Knuth last month, was brilliant.

"There comes a time in one's life, where some people realise they are gay, and others realise they are geeks!" -- knuth 2013

Thanks,

James
by jameswalmsley
Thu Jun 27, 2013 8:05 am
Forum: Bare metal, Assembly language
Topic: Building BitThunder for the RaspberryPi
Replies: 28
Views: 6429

Building BitThunder for the RaspberryPi

Hi, I thought I'd post my guide here to get people started: Please post any problems you encounter so that I can improve the build system and make it as convenient as possible. This is well tested under Ubuntu. Building works under Windows with MSYS, but I haven't been able to get the kconfig-fronte...
by jameswalmsley
Thu Jun 27, 2013 8:02 am
Forum: Bare metal, Assembly language
Topic: Announcing BitThunder (FreeRTOS based OS platform).
Replies: 9
Views: 6249

Re: Announcing BitThunder (FreeRTOS based OS platform).

Quick guide to building BitThunder on RaspberryPi: # Requirements (Aside from the compiler this should all just work on Ubuntu). * ARM Bare-metal compiler (codesourcery works fine). * Python (used in build system). * kconfig-frontends (kconfig-mconf tool). (http://ymorin.is-a-geek.org/projects/kconf...

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