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by clarkpadgett
Tue Dec 29, 2015 3:10 pm
Forum: Bare metal, Assembly language
Topic: Official LCD Display and Bare Metal Code
Replies: 3
Views: 1450

Re: Official LCD Display and Bare Metal Code

FYI, getting the touchscreen working is super easy. The code at https://github.com/raspberrypi/linux/bl ... i-ft5406.c shows you how.
by clarkpadgett
Mon Dec 28, 2015 3:09 am
Forum: Bare metal, Assembly language
Topic: Official LCD Display and Bare Metal Code
Replies: 3
Views: 1450

Re: Official LCD Display and Bare Metal Code

I've gotten mine working without any changes from before when I used HDMI. Try using 32 bpp instead of 16. Also, one other thing that I do is to 'and' the frame buffer address with ~0xC0000000 before using it.
by clarkpadgett
Fri Dec 25, 2015 2:36 pm
Forum: Bare metal, Assembly language
Topic: EMMC write multi block
Replies: 4
Views: 1447

Re: EMMC write multi block

Same for me. 2 seconds to 650 milliseconds. Thanks!
by clarkpadgett
Thu Dec 24, 2015 10:51 am
Forum: Bare metal, Assembly language
Topic: EMMC write multi block
Replies: 4
Views: 1447

Re: EMMC write multi block

I'm not sure about the reason why re-initialization is needed after a multi-block write, but you can speed up the writing by changing: else { // Card is still busy #ifdef EMMC_DEBUG printf("SD: card is busy, retrying\n"); #endif usleep(500000); } to: else { // Card is still busy #ifdef EMMC_DEBUG pr...
by clarkpadgett
Mon Dec 21, 2015 3:53 pm
Forum: Bare metal, Assembly language
Topic: Is there a better way to test and debug?
Replies: 12
Views: 3249

Re: Is there a better way to test and debug?

Get one of these: https://www.saikosystems.com/web/p-44-sd-to-microsd-converter.aspx Get one of these: http://www.amazon.com/Transcend-Wi-Fi-Class-Memory-TS16GWSDHC10/dp/B00A659IJI/ref=sr_1_2 Download busybox-armv5l from https://busybox.net/downloads/binaries/ and save it into a directory called 'bi...
by clarkpadgett
Fri Nov 27, 2015 1:18 pm
Forum: Bare metal, Assembly language
Topic: Ethernet: SPI vs USB
Replies: 2
Views: 1590

Re: Ethernet: SPI vs USB

ps2: I'm also looking for an text/video output device for my RPi (now I'm simply using the UART as a console). It has to be programmable in bare metal, so I guess all video output based on the on-board GPU is unacceptable. What could I use instead ? I'm using the official Raspberry Pi touch display...
by clarkpadgett
Fri Aug 28, 2015 9:18 am
Forum: Windows 10 for IoT
Topic: Delay microsecond support
Replies: 17
Views: 8572

Re: Delay microsecond support

Is there any way to use DMA with Windows IOT? I have a bare metal application where I am using DMA to write/read the DS18B20. The nice thing about doing it this way is that it runs independently of the CPU so you don't have to worry about the OS interrupting the time slots.
by clarkpadgett
Wed Feb 25, 2015 11:13 pm
Forum: Bare metal, Assembly language
Topic: 32gears: A serial port kernel loader for RPi2
Replies: 2
Views: 827

Re: 32gears: A serial port kernel loader for RPi2

The data rate is 115200 baud, so it works well for small kernels, but it is too slow for big kernels like Linux. Does the Pi 2 serial port actually support higher rates than 115200 baud? I seem to remember that the Pi 1 has too low reference clock connected to the UART, so higher speeds would be im...
by clarkpadgett
Sun Jan 25, 2015 12:32 pm
Forum: Bare metal, Assembly language
Topic: Bare metal programming - downloading programs
Replies: 12
Views: 3993

Re: Bare metal programming - downloading programs

I used Transcends Wifi SD card. I found information about hacking it and was able to turn it into an FTP server
by clarkpadgett
Wed Dec 24, 2014 3:45 pm
Forum: Bare metal, Assembly language
Topic: List of Hobby OSes
Replies: 1
Views: 1107

Re: List of Hobby OSes

If you're just looking for SD card access, take a look at https://github.com/jncronin/rpi-boot. I'm using his emmc.c along with the fatfs library. It's pretty slow because I don't have any caching set up, but it works well.
by clarkpadgett
Sat Nov 30, 2013 2:12 pm
Forum: Bare metal, Assembly language
Topic: bare metal programming in c/c++ ?
Replies: 8
Views: 5271

Re: bare metal programming in c/c++ ?

I'm using C++ for all of my bare metal play using newlib. (http://sourceware.org/newlib/). It is a bit of a chore to figure out all the requirements to make it work, but once you do, it works very well.
by clarkpadgett
Mon Nov 18, 2013 2:31 pm
Forum: Bare metal, Assembly language
Topic: small c++ code not working right
Replies: 8
Views: 2426

Re: small c++ code not working right

The problem is not that the UART is not working, but that the C++ code is not working. The UART works, because I can write individual characters. I also think the problem are my virtual functions. I will try if a non virtual variant is working. Ah yes, sorry about that. I need to learn to read more...
by clarkpadgett
Sun Nov 17, 2013 3:33 pm
Forum: Bare metal, Assembly language
Topic: small c++ code not working right
Replies: 8
Views: 2426

Re: small c++ code not working right

When I was writing my UART code, I had to set GPIO 14 and 15 to ALT5 before enabling the UART before I could get it working. I can't say that that is the problem you are having, but it's worth a try.
by clarkpadgett
Thu Aug 29, 2013 11:17 am
Forum: Bare metal, Assembly language
Topic: Bare Metal Reboot
Replies: 4
Views: 2884

Re: Bare Metal Reboot

The watchdog timer code can be found here: https://github.com/dwelch67/raspberrypi ... /blinker06
by clarkpadgett
Thu Aug 29, 2013 10:55 am
Forum: Bare metal, Assembly language
Topic: Bare Metal Reboot
Replies: 4
Views: 2884

Re: Bare Metal Reboot

If you set up the Pi's watchdog timer and go into an infinite loop, the Pi should reset when the timer runs out. I remember seeing somewhere in dwelch67's code an example of setting up that timer.
by clarkpadgett
Tue Aug 20, 2013 1:22 pm
Forum: Bare metal, Assembly language
Topic: FTP kernel.img to your SD card.
Replies: 5
Views: 2444

FTP kernel.img to your SD card.

After reading a blog where a guy had hacked a Transcend Wi-Fi SD card (http://haxit.blogspot.ch/2013/08/hacking-transcend-wifi-sd-cards.html), I ordered one to see what I could do with it. It turns out I can start an FTP server and transfer my kernel.img directly to the SD card. First, I downloaded ...

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