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by bts
Sun Dec 22, 2013 2:37 pm
Forum: Bare metal, Assembly language
Topic: System Timer Interrupts? (Or using interrupts at all)
Replies: 12
Views: 16789

Re: System Timer Interrupts? (Or using interrupts at all)

Actually BCM manual is quite garbled as for interrupts... I've managed to generate them (in case of GPIO though), so I'll write things you need to do (it won't be huge difference with enabling timer interrupts): 1) set interrupt vector table - it will tell "where to go" after interrupt is triggered,...
by bts
Sat Oct 19, 2013 3:52 pm
Forum: Other projects
Topic: HY28A-LCDB, ili9320 (working)
Replies: 131
Views: 39083

Re: HY28A-LCDB, ili9320 (working)

Hello guys. I've written some code for this LCD recently... main difference between mine and all these mentioned before is that mine is aimed to work on bare metal. I created it mainly for educational purposes, but in case somebody finds it useful I share it here. Feel free to use that code. Link (o...
by bts
Mon Jul 22, 2013 5:11 pm
Forum: Bare metal, Assembly language
Topic: Weird problem with .word
Replies: 4
Views: 1224

Re: Weird problem with .word

Dweich67, you're right. I've already noticed that trick done by assembler. 8158: e59f400c ldr r4, [pc, #12] ; 816c <loop+0x4> 815c: e5940000 ldr r0, [r4] 8160: e3500000 cmp r0, #0 ; 0x0 8164: 0bffffed bleq 8120 <flash> 00008168 <loop>: 8168: eafffffe b 8168 <loop> 816c: 00008190 .word 0x00008190 So ...
by bts
Sun Jul 21, 2013 9:45 pm
Forum: Bare metal, Assembly language
Topic: Weird problem with .word
Replies: 4
Views: 1224

Re: Weird problem with .word

Thanks for your answer. Are you sure that ldr r4, =variable loads the *content* of variable, though? According to the ARM information center: LDR r2,=place ; loads the address of ; place into r2 ; => LDR r2,[pc,offset_to_litpool] ; ... ; litpool DCD place Link . This equal sign should make a differe...
by bts
Sun Jul 21, 2013 4:18 pm
Forum: Bare metal, Assembly language
Topic: Weird problem with .word
Replies: 4
Views: 1224

Weird problem with .word

Hello. I'm writing some simple code, aimed to work on bare metal Raspberry. It consists of two files: main.s and gpio.s. There is a function in gpio.s, which turns the ACT LED on and off ("flash"). Let me show what's in the main.s: .section .data .align 2 variable: .word 16 .section .init .globl _st...

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