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by dwelch67
Sat May 26, 2012 11:34 pm
Forum: Other programming languages
Topic: Programming the ARM chip
Replies: 134
Views: 40301

Re: Programming the ARM chip

That was probably it. The docs say you should config the gpio first, that may have caused something on the rx, causing an interrupt. So I disabled the interrupts first, then disabled the uart, then was able to configure the gpio, and then configure and enable the uart. Not working yet, but over that...
by dwelch67
Sat May 26, 2012 10:34 pm
Forum: Other programming languages
Topic: Programming the ARM chip
Replies: 134
Views: 40301

Re: Programming the ARM chip

Yes, all bare metal.

Using physical addressing, replace 0x7Exxxxxx with 0x20xxxxxx, can blink leds and talk to timers and such, moving toward bringing up one of the uarts. Prefer the mini uart to the full uart, but am having problems with the mini.
by dwelch67
Sat May 26, 2012 10:01 pm
Forum: Other programming languages
Topic: Programming the ARM chip
Replies: 134
Views: 40301

Re: Programming the ARM chip

And getting hangs talking to the mini-uart. I write a 0x1 to the AUX_ENABLES then try to write to the control register in the mini uart and that appears to cause a hang. Am I missing something?
by dwelch67
Sat May 26, 2012 9:42 pm
Forum: Other programming languages
Topic: Programming the ARM chip
Replies: 134
Views: 40301

Re: Programming the ARM chip

I am struggling to turn off the pull down for GPIO14 and 15 (UART). from the diagram in the docs it implies that pull up/down are indpendent of function/alternate function. is that correct? If I have switched to the alternate function for the GPIO do I need to modify the pull up/down? What I am doin...
by dwelch67
Sat May 26, 2012 6:05 pm
Forum: Other programming languages
Topic: Programming the ARM chip
Replies: 134
Views: 40301

Re: Programming the ARM chip

Got my (first) raspberry pi yesterday http://github.com/dwelch67/raspberrypi I have just started a set of bare metal arm programming examples for the rpi. Quite disappointed that the arm jtag is not easier to get to. If nothing else a very small kernel.img that changes gpio pins to alternate functio...

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