1. 02 Feb, 2015 1 commit
    • Ben Avison's avatar
      Add support for Raspberry Pi Compute module and Raspberry Pi 2 · 60752490
      Ben Avison authored
        * Compute module support consists of eMMC support in the SDHCI driver. The
          eMMC chip on the Compute module only works reliably if under-clocked to
          25 MHz.
        * Pi 1 vs Pi 2 differences are selected at runtime by checking the CPU ID,
          so a single ROM image will work with both boards.
        * Added ARMv7 cache maintenance routine for use on Pi 2.
        * The physical address of the peripherals has moved in Pi 2 to make space
          for the 1 GB of RAM.
        * The ARM physical address space is mapped differently onto the GPU
          address space in Pi 2 because the ARM now uses the L2 cache that comes
          with the Cortex-A7 instead of the GPU's L2 cache.
        * Still waiting for confirmation on the board revision ID that will be
          used for Pi 2, so may require further tweaks for production releases.
      Version 0.40. Tagged as 'BCM2835-0_40'
  2. 30 Oct, 2014 1 commit
  3. 14 Jul, 2014 1 commit
    • Ben Avison's avatar
      Support the Raspberry Pi model B+ · 4830dcfe
      Ben Avison authored
        The activity GPIO pin has been reassigned and its sense is inverted,
        compared to earlier boards. More importantly, the SD card detect pin has
        been removed entirely, so we need to signal to the SD stack to use its
        new timeout-based state machine (rather than polling for card presence).
        Already in use in RC12a.
      Version 0.35. Tagged as 'BCM2835-0_35'
  4. 01 Jul, 2012 1 commit
    • Ben Avison's avatar
      Fixes for SD support · 60ebea68
      Ben Avison authored
        * Engage the GPIO controller's pull-up resistors on SDCLK, CMD and DAT0-DAT3.
          In tests, this seems to address the worst of the unreliability we have
          seen previously.
        * Remove the entry to change the bus between push-pull and open-drain modes.
          The BCM2835 simply doesn't seem to be able to do this. Fortunately, all
          the cards I have tested seem to be OK with the GPIO controller's pull-up
          on the CMD line (however strong that is - it's undocumented) engaged at
          all times.
        * Time a dummy command in order to calculate the speed of the input clock
          to the SD controller block (there doesn't appear to be any way to read
          its speed directly!) This is necessary because recent versions of the
          firmware have not only changed the default clock speed, but even made it
          a user-configurable option in config.txt. It's very important that we
          know how fast it is - if we set the dividers so SDCLK is too slow, then
          the workaround for the register write bug won't work, too fast and we
          overclock the cards, potentially damaging them.
        * Re-enable high speed mode. As long as we don't use the High Speed Enable
          bit in Host Control 1 (see change in SDIODriver 0.03) this seems to work
          for me.
        Tested against my collection of test cards on a Raspberry Pi with the
        firmware from the 2012-06-22 commit on github, and with
        init_emmc_clock=100000000 in config.txt (though other values, or the
        absence of that line, or the entire file, should also work). The only
        issues I had appeared to be due to mechanical problems with the SD socket,
        and went away after the card was reseated one or more times.
      Version 0.10. Tagged as 'BCM2835-0_10'
  5. 15 Jun, 2012 1 commit
    • Ben Avison's avatar
      SD support, and miscellaneous other changes · 981cfe6d
      Ben Avison authored
        * Bugfix to HAL_FIQDisableAll - it wasn't clearing the FIQ register (would
          only have caused trouble in practice if the same device was subsequently
          enabled as an IRQ).
        * Added a load of memory barriers to s.Interrupts and s.Timers to conform
          to the requirement stated in 1.3 of the datasheet.
        * Added a HAL device for the Arasan SDHCI controller. Note that this does
          not currently work reliably, and results vary from card to card. High
          speed support is currently disabled until we are able to verify that it
          works reliably.
        * Added a sprinkling of "GET Hdr:ListOpts" because the space reserved for
          the SDHCI HAL device in hdr.StaticWS is determined by including
          Hdr:HALDevice and Hdr:SDHCIDevice, which need it.
        * When support for saving "CMOS" to the SD card is added, the ROM image
          file (kernel.img) is the only one we can count on the bootloader
          installing in memory, so I think we're going to have to work using the
          table in s.CMOS. Broadcom seems to like messing around with the space
          just after the processor vector table, so rather than adding a pointer
          to the table there, I've opted to mark it using a magic word.
        Tested on a Raspberry Pi - as noted above, there are reliability issues.
      Version 0.09. Tagged as 'BCM2835-0_09'