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by Ultibo
Sat Jan 02, 2016 10:25 am
Forum: Bare metal, Assembly language
Topic: RPi 2 boots in HYP mode (bare metal)
Replies: 8
Views: 3752

Re: RPi 2 boots in HYP mode (bare metal)

but I cant find anyone interested or describing how to switch to PL1/Secure from PL2/Non-Secure(HYP). ...wonder if they do something to you up front or if you are basically left in supervisor mode. Just to follow up on this chain, the firmware changed back in October 2015 put the RPi2 into HYP mode...
by Ultibo
Tue Dec 22, 2015 1:29 am
Forum: Bare metal, Assembly language
Topic: Initializing RAM on Raspberry Pi 2
Replies: 16
Views: 2316

Re: Initializing RAM on Raspberry Pi 2

Thanks for that, solved the problem really easily. Just to be clear on word alignment, if I make a new function like this: void put8(unsigned long int addr, char val) { volatile char *a; a = addr; *a = val; } then I should be able to write to an odd address like 0x00FFFFFF? It depends on what instr...
by Ultibo
Mon Dec 21, 2015 11:51 pm
Forum: Bare metal, Assembly language
Topic: Initializing RAM on Raspberry Pi 2
Replies: 16
Views: 2316

Re: Initializing RAM on Raspberry Pi 2

Hi All, I have a question about the Raspberry Pi 2's RAM at a bare metal startup. Do I need to "set up" the RAM located after the .text and the .data sections of the code if I want to use it during the program? I have a bit of code to just read and write 32 bit values to RAM that just turns on the ...
by Ultibo
Sun Nov 01, 2015 9:14 am
Forum: Bare metal, Assembly language
Topic: 1920x1080 60Hz text output
Replies: 17
Views: 3094

Re: 1920x1080 60Hz text output

I cannot use linux it will be a product that will be sold. I need to make it available in 6 - 9 months from now. So, if Raspberry can do it, great, if not, I will have to find something else. But if the GPU supports the resolution, the programmers can make a way to communicated with the gpu using 1...
by Ultibo
Fri Oct 16, 2015 9:38 am
Forum: Bare metal, Assembly language
Topic: Data Cache not working with Baking Pi - SOLVED
Replies: 11
Views: 3893

Re: Data Cache not working with Baking Pi

Just a little bit of extra info with regard to the RPi (not RPi 2) and cached / shared memory. Because the RPi shares the L2 cache with the GPU you can mark memory as Cached (Write back) and Shared and pass that memory to the USB DMA buffer (you still need to translate physical to bus addresses) and...
by Ultibo
Fri Oct 16, 2015 9:08 am
Forum: Bare metal, Assembly language
Topic: Pi 2 extra cores operation
Replies: 5
Views: 1819

Re: Pi 2 extra cores operation

From the comments it looks like I will not be able to play with the TrustZone functionality while having the kernel read boot parameters via ATAGS/dtb in a Linux compatible manner. While TrustZone is not in play right now, I might still want to look into that later. Hi JacobL, Thought you might be ...
by Ultibo
Fri Oct 02, 2015 6:56 am
Forum: Bare metal, Assembly language
Topic: Framebuffer issue with latest firmware
Replies: 5
Views: 1604

Re: Framebuffer issue with latest firmware

Finally figured out what changed, with the most recent firmware the mailbox call returns the address of the framebuffer as a bus address (eg in the 0xC0000000 range) which must be converted to a physical address for the ARM otherwise the writes to the framebuffer seem to go nowhere. Not sure when th...
by Ultibo
Wed Sep 30, 2015 11:00 am
Forum: Bare metal, Assembly language
Topic: Framebuffer issue with latest firmware
Replies: 5
Views: 1604

Framebuffer issue with latest firmware

Wondering if anyone has noticed an issue using the RPi Framebuffer from bare metal with very recent versions of the firmware? Using code that is known to work on both Pi1 and 2, if I use firmware downloaded this week all I see is a black screen. Debugging via blinking LED shows that all the calls to...

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