On Thu, Apr 10, 2014 at 7:11 PM, Andre Marques < andre.lousa.marq...@gmail.com> wrote:
> On 04/04/14 20:19, Joel Sherrill wrote: > >> On 4/4/2014 1:15 PM, Gedare Bloom wrote: >> >>> The license looked fine to me. >>> >> +1 >> >> As always, we just need to be careful on a file per file basis just in >> case >> something else in rpi-boot has a different license. >> > > All files in rpi-boot use a similar licence, so I will be using some code > from rpi-boot as a base for this. Great. > > > On Thu, Apr 3, 2014 at 10:06 PM, Alan Cudmore <alan.cudm...@gmail.com> >>> wrote: >>> >>>> From my limited research, it looks like the emmc controller in the >>>> Raspberry >>>> Pi BCM2835 may be the way to go. >>>> It looks like it is a high level controller for the SD/MMC card slot on >>>> the >>>> Pi. >>>> >>>> Since this is a custom controller, I don't think there would be an >>>> existing >>>> driver in RTEMS. >>>> >>>> It seems that this emmc controller in the Pi may handle different types >>>> of >>>> cards, and at a higher level than just using the SPI bus to access the >>>> card. >>>> ( This is based on some searches of conversations on the raspberry pi >>>> forums >>>> , not my experience ) >>>> >>>> You would have to write a driver for this emmc controller and provide >>>> the >>>> interface to libblock for the file system interface on RTEMS. The code >>>> you >>>> have linked above for rpi-boot looks like it has a permissive license, >>>> so it >>>> *may* be possible to use this code in the RTEMS driver. There is some >>>> other >>>> potentially useful code in there too. >>>> >>> > The mailbox access, mmio read and write and the timer code will also be > usefull, and not only for emmc. This timer code differs from the > misc/timer.h currently in the raspberrypi BSP, as it waits a certain amount > of time (until some register gets updated). The misc/timer.h is a benchmark > timer, so one of them would have to be renamed or reorganized. > > Can an RTEMS timer be used for the mailbox communication? Also, I don't think the benchmark timer code in the RTEMS Raspberry Pi BSP is functional. I have been contacted by someone who is currently working on a console driver for the BSP, and has been able to display fonts. We may want to include him, because I think the graphics code uses mailbox communication to the GPU. It is very interesting that the GPU is running a commercial RTOS, and we will be communicating to it with RTEMS. > My plan was to have at the root of the raspberrypi BSP a folder "emmc" for > the emmc driver code, and the mailbox, mmio and timer on the misc folder, > with the headers on the include folder. What do you think? > > I have been trying the rpi-boot emmc code for the past week, and I > modified the hello test to use the emmc driver (an overly simplified > version of the rpi-boot, just to read the slot info register for now), and > my compilation process has been: > > 1. Add/change files in Raspberrypi BSP > 2. Update Makefile.am > 3. Run bootstrap -p and bootstrap from the RaspberryPi BSP folder > 4. (Re)configure RTEMS > 5. make and make install RTEMS from the root folder > > That is pretty much what I do. Although it might be possible to test drivers and code in the RKI image, then integrate it into the RTEMS tree when it is ready. > I have been using the --enable-maintainer-mode, but I am not sure about > exacly what it simplifies, because I always needed to do those steps for it > to compile and link correctly. > I don't know what this does either.. Alan > > --André Marques > > > >>>> I'll have to try the serial bootloader, I am also close to ordering an >>>> inexpensive JTAG adapter to try loading and debugging through JTAG. >>>> uboot is >>>> another possibility, using a TFTP server. >>>> >>>> Alan >>>> >>>> >>>> >>>> >>>> On Wed, Apr 2, 2014 at 12:02 PM, Andre Marques >>>> <andre.lousa.marq...@gmail.com> wrote: >>>> >>>>> Hello, >>>>> >>>>> I'm intending to work in the SD card support for the Raspberry Pi BSP, >>>>> using the SD mode instead of the SPI mode. >>>>> >>>>> The references I have gathered so far for this are as follows: >>>>> >>>>> The Raspberry Pi SOC guide: Broadcom BCM2835 Peripherals Guide >>>>> (Chapter 5 >>>>> - EMMC) >>>>> >>>>> The simplified SD standard - >>>>> https://www.sdcard.org/downloads/pls/simplified_specs/ >>>>> >>>>> And the following github code - >>>>> https://github.com/jncronin/rpi-boot/blob/master/emmc.c >>>>> >>>>> There is also the libchip/i2c/spi-sd-card libi2c driver, which can >>>>> also be >>>>> a reference (even though it uses SPI). >>>>> >>>>> Now, the questions: >>>>> >>>>> Should I use the Generic Disk Device driver, as the >>>>> libchip/i2c/spi-sd-card ? >>>>> >>>>> Is there any driver using the SD mode for sd card access, or using an >>>>> emmc >>>>> interface currently in the RTEMS code base? I haven't found any. >>>>> >>>>> On a side note, I managed to send RTEMS applications to the RPi though >>>>> the >>>>> UART interface using the xmodem protocol. >>>>> >>>>> For that I used the following bootloader >>>>> >>>>> https://github.com/dwelch67/raspberrypi/tree/master/bootloader05 >>>>> >>>>> It takes me 2 minutes to send 1 MB of data to the RPi, but this could >>>>> be >>>>> improved if it used 1024 byte block transfer instead of the default of >>>>> 128. >>>>> The bootloader loads the transfered program to memory and runs it. >>>>> Then the >>>>> RPi must be rebooted so a new program can be sent. >>>>> >>>>> It may not be the best way, but only requires an usb-to-uart cable, and >>>>> avoids the current SD card "dance" to run programs on the Pi. >>>>> >>>>> Thank you for your time. >>>>> >>>>> --André Marques >>>>> >>>>> >>>>> _______________________________________________ >>>> rtems-devel mailing list >>>> rtems-devel@rtems.org >>>> http://www.rtems.org/mailman/listinfo/rtems-devel >>>> >>>> _______________________________________________ >>> rtems-devel mailing list >>> rtems-devel@rtems.org >>> http://www.rtems.org/mailman/listinfo/rtems-devel >>> >> >
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