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by gnif
Fri Oct 12, 2012 2:39 am
Forum: Bare metal, Assembly language
Topic: Has anyone got OpenGL working in their kernel?
Replies: 18
Views: 5498

Re: Has anyone got OpenGL working in their kernel?

@dwelch67 - The stm32f103 is supported for openocd flash, I also develop on this board, and the Olimex ARM-USB-OCD-H can be had for < $40 from ebay, and works with openocd out of the box also, it is USB and as such has no serial port speed issues.
by gnif
Thu Oct 11, 2012 10:25 am
Forum: Bare metal, Assembly language
Topic: Has anyone got OpenGL working in their kernel?
Replies: 18
Views: 5498

Re: Has anyone got OpenGL working in their kernel?

@richcole - I have the EXACT same device here, works well except for one flaw... the CTS and RTS signals are not connected... It would receive data, but refused to send. I had to bridge those tiny little pins on the chip (5 & 6 and 8 & 9) before I could use it to communicate with a router. Edit: Sor...
by gnif
Thu Oct 11, 2012 10:10 am
Forum: Bare metal, Assembly language
Topic: Full Interrupt controller table
Replies: 6
Views: 2941

Re: Full Interrupt controller table

So am I right in reading this, that this will enable the DMA0 IRQ?

Code: Select all

*(volatile uint32_t *)0x2000b214 |= 0x20;
by gnif
Thu Oct 11, 2012 2:08 am
Forum: Bare metal, Assembly language
Topic: Has anyone got OpenGL working in their kernel?
Replies: 18
Views: 5498

Re: Has anyone got OpenGL working in their kernel?

@inder - I will see about posting some pics later, but to answer your other questions I do not use a wiggler cable anymore, none of my PCs have LPT ports anymore, and also it is quite slow. I spent the $30-$40 for a Olimex ARM-USB-OCD-H which works really nice under Linux and is stacks faster then t...
by gnif
Wed Oct 10, 2012 1:13 pm
Forum: Bare metal, Assembly language
Topic: Has anyone got OpenGL working in their kernel?
Replies: 18
Views: 5498

Re: Has anyone got OpenGL working in their kernel?

Further research shows that OpenGL is just a library that is calling the lower levels to perform the accelerated functions, in this case, the VideoCore closed binaries. So until someone figures out how to do some 2d accelerated operations without the closed binaries we are stuck with the slow frame ...
by gnif
Wed Oct 10, 2012 1:57 am
Forum: Bare metal, Assembly language
Topic: Has anyone got OpenGL working in their kernel?
Replies: 18
Views: 5498

Re: Has anyone got OpenGL working in their kernel?

I am just about to start investigating the OpenGL path as I want the same thing. As for debugging, I am using a USB JTAG interface with OpenOCD. I have the older board so I had to patch S5-11 into the P1 header to make it work, but this allows code stepping and is invaluable to bare metal developmen...
by gnif
Tue Oct 09, 2012 4:37 pm
Forum: Bare metal, Assembly language
Topic: Unable to make DMA work
Replies: 5
Views: 2124

Re: Unable to make DMA work

Looks like I found the problem...

Code: Select all

__attribute__((packed))
Seems that when a struct's members are already all aligned, this causes GCC to produce crazy code on some platforms, such as ARM and ia64.
by gnif
Tue Oct 09, 2012 4:14 pm
Forum: Bare metal, Assembly language
Topic: Unable to make DMA work
Replies: 5
Views: 2124

Re: Unable to make DMA work

Thanks for the info, I have managed to get text output to the framebuffer working and have discovered something odd... either my understanding of pointers in C is flawed, or something very odd is going on here: DMARegisters definition: typedef struct DMARegisters { volatile uint32_t CS; /* control a...
by gnif
Tue Oct 09, 2012 12:39 pm
Forum: Bare metal, Assembly language
Topic: Unable to make DMA work
Replies: 5
Views: 2124

Re: Unable to make DMA work

According to documentation the value should just sit there until the enable bit is set. I also doubt there is a timing issue here as I am using JTAG to inspect. Until I get a frame buffer with text output going I cant be certain, this project is still very young (18 hours).
by gnif
Tue Oct 09, 2012 10:28 am
Forum: Bare metal, Assembly language
Topic: Unable to make DMA work
Replies: 5
Views: 2124

Unable to make DMA work

Hi, I am trying to perform a DMA transfer from a buffer in SDRAM to the mapped VideoCore frame buffer. What is strange is I am setting CONBLK_AD as per the documentation, but it is not set to the correct value, and I will be dammed if I can figure out what the heck is going on. Here is the GDB outpu...

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