Go to advanced search

by mvdhoning
Mon Oct 08, 2012 5:59 pm
Forum: Troubleshooting
Topic: Disintergrated SD card -> No booting RasPi unknown block
Replies: 22
Views: 2817

Re: Disintergrated SD card -> No booting RasPi unknown block

i suspect my rpi pin 8 finger to just make enough contact to let the boot process start (it did not want to continue booting before i lifted the finger) but not enough contact to transfer data for linux reliably. maybe you can cut the cellotape and tape it on pin8 of the sdcard. but personaly i dont...
by mvdhoning
Mon Oct 08, 2012 5:51 pm
Forum: Bare metal, Assembly language
Topic: Bare metal framebuffer in C
Replies: 43
Views: 17660

Re: Bare metal framebuffer in C

i am ok now as for as drawing on the frame-buffer goes. somehow writing a byte as an longword gave some unwanted side effect as that overwrote some previously written values. in order to get writing to a 24 bit mode working (3 bytes) i introduced a packed record as there is no native type in freepas...
by mvdhoning
Sun Oct 07, 2012 5:51 pm
Forum: Bare metal, Assembly language
Topic: Bare metal framebuffer in C
Replies: 43
Views: 17660

Re: Bare metal framebuffer in C

:oops:

i made tempfb a pointer to longword and not a pointer to a byte

now i get a white'ish screen as expected.
by mvdhoning
Sun Oct 07, 2012 4:29 pm
Forum: Bare metal, Assembly language
Topic: Bare metal framebuffer in C
Replies: 43
Views: 17660

Re: Bare metal framebuffer in C

thanks for the hint on the sd card adapter i should have bought one earlier. but must be me doing something wrong i am sure :-) i tried your kernel.img and it just shows your logo and 2 buttons fine. instead of an 16 bit mode i now tried a 1024x768 24 bit mode. and wierdly enough it shows red green ...
by mvdhoning
Sun Oct 07, 2012 3:40 pm
Forum: Troubleshooting
Topic: Disintergrated SD card -> No booting RasPi unknown block
Replies: 22
Views: 2817

Re: Disintergrated SD card -> No booting RasPi unknown block

in my case pin 8 connector is the 'damaged ' one. it is in the corner where the piece of sdcard was left in the slot and that connector is a bit lower then the others. and if that one is not used for data transfer on first boot it explains why the kernels do load for me but linux cannot continue as ...
by mvdhoning
Sun Oct 07, 2012 1:20 pm
Forum: Bare metal, Assembly language
Topic: Bare metal framebuffer in C
Replies: 43
Views: 17660

Re: Bare metal framebuffer in C

now i get something on screen, but ... i have to follow brians way of using channel 8. The way with channel 1 and the record still wont work for me. and it does not look good, the pixels drawn to the left side of the screen are drawn bright and the pixels next to that are dimmer of color also every ...
by mvdhoning
Sun Oct 07, 2012 11:35 am
Forum: Troubleshooting
Topic: Disintergrated SD card -> No booting RasPi unknown block
Replies: 22
Views: 2817

Re: Disintergrated SD card -> No booting RasPi unknown block

same here :-( but initialy after removing the snapped corner from the sdcard slot on the rpi and using a another sdcard my rpi refused to boot. on investigating the rpi sdcard slot it appeared that contact in the corner where was a little flat compared to the others. with it being broke i though let...
by mvdhoning
Sun Sep 30, 2012 7:10 pm
Forum: Bare metal, Assembly language
Topic: Bare metal framebuffer in C
Replies: 43
Views: 17660

Re: Bare metal framebuffer in C

DexOS wrote:Do you add 1 to the write mailbox 0x2000B8A0 +1 ?, i may of just mist it.
He does not seem to do that ( i don't do that either ) is there a reason why we should not use MAILBOX0_WRITE?
by mvdhoning
Sun Sep 30, 2012 6:56 pm
Forum: Bare metal, Assembly language
Topic: Detecting if HDMI present
Replies: 17
Views: 14147

Re: Detecting if HDMI present

Thanks for saying i should write a function to write out what is returned from the mailbox as that triggered me to recheck that code on errors and i found a big error in my unsigned int to hex function. Thanks for pointing me there. That confirms i was going in the right direction. Although i could ...
by mvdhoning
Sun Sep 30, 2012 6:34 pm
Forum: Bare metal, Assembly language
Topic: Bare metal framebuffer in C
Replies: 43
Views: 17660

Re: Bare metal framebuffer in C

Same for me ;-) But yesterday (and today) i decided to take another side step and use the mailbox interface to read out screen resolution and that gave me wrong values also namely 0. Info on the mailbox property interface: https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface Brian...
by mvdhoning
Sun Sep 30, 2012 6:03 pm
Forum: Bare metal, Assembly language
Topic: getting the mini uart to work
Replies: 14
Views: 4364

Re: getting the mini uart to work

I like the fact that uart01 does not have all in it so i can focus on understanding that first :-) So that i dont forget i made a page explaining what is going on with uart01 at: http://code.google.com/p/fprpbm/wiki/MiniUart Also my needs are only to write out some debug values and i can do that now...
by mvdhoning
Sat Sep 29, 2012 3:15 pm
Forum: Bare metal, Assembly language
Topic: Detecting if HDMI present
Replies: 17
Views: 14147

Re: Detecting if HDMI present

could you post some example code on this? (that is on reading display info, not on sdcard)
by mvdhoning
Tue Sep 25, 2012 6:39 pm
Forum: Bare metal, Assembly language
Topic: getting the mini uart to work
Replies: 14
Views: 4364

Re: getting the mini uart to work

Thanks that makes things clearer but i am stil trying to understand the disable pull up down step: 1) pull up or down is removed by setting cppud to 0 (disable pull up down) 2) we wait a while 3) we set bit 14 for gppudclk0 (clock control signal that we set to disable to pin14) 4) we wait a while 5)...
by mvdhoning
Sun Sep 23, 2012 6:34 pm
Forum: Bare metal, Assembly language
Topic: documentation + errata
Replies: 2
Views: 1532

Re: documentation + errata

Oh i totally missed that that is the same :oops: . I always got lost at the first page you get to from the wiki.
by mvdhoning
Sun Sep 23, 2012 3:58 pm
Forum: Bare metal, Assembly language
Topic: documentation + errata
Replies: 2
Views: 1532

documentation + errata

Getting to do bare metal programming without documentation is impossible.

So here a pointer to all/most the documentation needed including errata:
http://elinux.org/RPi_Documentation

So no more scavenger hunting for documentation thanks to the people at elinux.
by mvdhoning
Sun Sep 23, 2012 10:04 am
Forum: Bare metal, Assembly language
Topic: getting the mini uart to work
Replies: 14
Views: 4364

Re: getting the mini uart to work

as always after posting a question on a forum you find a solutions yourself ;-) spot the difference: wrong: while(true) do begin if (GET32(AUX_MU_LSR_REG)=$20) then break; end; correct: while(true) do begin if boolean(GET32(AUX_MU_LSR_REG) and $20)=true then break; end; However it would still be nic...
by mvdhoning
Sun Sep 23, 2012 9:37 am
Forum: Bare metal, Assembly language
Topic: getting the mini uart to work
Replies: 14
Views: 4364

getting the mini uart to work

trying the uart01 code from dwelch i only got some giberish on the screen and not 0123456789 repeatedly. After making the main loop look like this: ra=0; while(1) { while(1) { if(GET32(AUX_MU_LSR_REG)&0x20) break; } PUT32(AUX_MU_IO_REG,0x30+(ra)); ra=ra+1; if (ra>9) ra=0; } it sometimes works and so...
by mvdhoning
Fri Sep 14, 2012 2:59 pm
Forum: Bare metal, Assembly language
Topic: Bare Metal with FreePascal on the Raspberry Pi
Replies: 1
Views: 2369

Bare Metal with FreePascal on the Raspberry Pi

Following the assembly bare metal tutorial on http://www.cl.cam.ac.uk/freshers/raspberrypi/tutorials/os/ i got inspired to go and try bare metal programming on the raspberry pi using the pascal programming language. First i needed a freepascal crosscompiler to target the raspberry pi. Instruction ar...

Go to advanced search