GitLab

Detail:
  Firmware as of 28th July will allow the GPU to make use of the top 16MB of RAM in 1GB machines. This overlaps the ARM's IO space, essentially making that area of memory inaccessible to us.
  This causes problems because we rely on a couple of buffers which are located in VC memory (virtual GPIO buffer & FT5406 touchscreen buffer)
  At some point extra mailbox messages were added to allow the ARM to dictate the location of these buffers; so make use of those messages wherever possible.
  File changes:
  s/Messaging - Remove VirtGPIOBuf and TouchBuf related tags from the initialisation tag sequence. Add new GetVCBuffer function that can be called post-MMU init to deal with getting/setting the buffer addresses.
  s/Top - Use GetVCBuffer to initialise VirtGPIOBuf
  s/Touch - Use GetVCBuffer to get touchscreen buffer
  hdr/StaticWS - Remove TouchBuf from workspace, no longer needed
Admin:
  Tested on Raspberry Pi 3 with firmware from March 2016 (Set commands not supported), 21st July 2017 (set commands supported, but upper 16MB not used), 28th July 2017 (set commands supported and necessary)


Version 0.71. Tagged as 'BCM2835-0_71'

The SDIO HAL device reports when it is sure fixed disc media is attached (ie. eMMC soldered on the same PCB) which causes SDFS to report this to FileCore as a fixed disc, skipping the removable safety checks.
However, CM3 and CM3L both return the same board id so we can't work out which is which. Additionally, someone could attach an external eMMC in theory on a custom expansion board (instead of an SD card socket like the CMIO has).
To resolve this, we assign IO expander line 6 of U8 to be a safety catch. If that line is held low, it signifies this is definitely a CM3 - in effect this is a "definitely has eMMC" or "maybe has eMMC" switch.

Tested on CM1, CM3, CM3L, and a suitably modified CM3 with the help of Chris Hall.

Version 0.69. Tagged as 'BCM2835-0_69'

Remove the baffling double indirection of RamAd (and unused exports SerNo and MacAdd), and treat these the same as the other pre-HAL_Init query results.
This means the scope of the tagbuffer is limited to Messaging.s, rather than having to be kept preserved globally.
Use memcpy() to copy tag list to tagbuffer for clarity.
Tested on a Pi 3.

Version 0.68. Tagged as 'BCM2835-0_68'

In HAL_QueryPlatform a mixture of register naming overlooks r6 (aka v3) gets used, but not preserved.
Uppercase opcodes, add a few more comments around the CRC calculation.

Detail:
  hdr/BCM2835 - Remove mailbox definitions - use the ones exported by BCMSupport to avoid needless duplication
  hdr/StaticWS, s/Messaging, s/Top - Use the mailbox property interface to request & map in the virtual GPIO buffer (if present)
  s/SDIO - On the Pi 3B, the GPIO that was used for the SD activity GPIO is now used for a different purpose. To control the activity LED we need to go via an I2C attached GPIO extender, which itself is exposed to the ARM via the new "virtual GPIO" buffer
  s/VCHIQ - Update to use BCMSupport mailbox definitions
Admin:
  Tested on Pi 1B, 3B


Version 0.54. Tagged as 'BCM2835-0_54'

Detail:
  s/Messaging - Ensure the PL011 UART module clock is set to 3MHz on startup, in order to allow the debug terminal to work
  hdr/StaticWS, s/Top - Add a basic HAL device to expose the GPU mailboxes
Admin:
  Tested on Raspberry Pi 1B/2B/3B
  Fixes garbled debug terminal input/output on Pi 3


Version 0.52. Tagged as 'BCM2835-0_52'

Detail:
  Makefile, s/Touch - Basic HAL device for the official touchscreen, which just exposes the address of the buffer which the GPU periodically fills with a register dump of the touchscreen controller.
  hdr/BCM2835 - Remove old comment. Add new tag for getting the touchscreen buffer address.
  hdr/StaticWS - Remove old workspace entries. Add new entries for touchscreen.
  s/Messaging - Remove the messagebox tags which set a screen mode on startup (BCMVideo will handle that for us), and just blank the screen instead (to stop the GPU displaying a coloured square). Add tag to get the touchscreen buffer address.
  s/Top - Register touchscreen HAL device during HAL_InitDevices. Remove more old code.
Admin:
  Tested on Raspberry Pi 1 B


Version 0.50. Tagged as 'BCM2835-0_50'

Detail:
  * 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'

Detail:
  hdr/StaticWS, s/Top, s/Video - Added a simple VDU HAL device that exposes a DMA channel to BCMVideo for use with GraphicsV_Render
  hdr/BCM2835 - Don't allow DMA channel 12 to be used; latest firmware seems to have a bug which claims its free when in reality it isn't.
  s/Messaging, s/DMA - Adjust DMA init to allow the video device to claim a DMA channel before the DMA devices are initialised
Admin:
  Tested on Raspberry Pi with high processor vectors


Version 0.25. Tagged as 'BCM2835-0_25'

Read board model, revision, and available DMA channels from messaging channel. Report board revision via GPIO HAL device. Recover lost ROM relocation code.

Detail:
  hdr/StaticWS, s/Messaging, s/Top - Now reads board model, revision and available DMA channels from messaging channel
  hdr/StaticWS, s/GPIO - Updated GPIO HAL device to report board revision instead of a generic response of 'unknown'
  s/Top - Recovered ROM relocation code that got lost during a merge. End of ROM image no longer being corrupted, and RISC OS now sees correct amount of RAM.
  s/DMA - Ditch old code to read available DMA channels and use value read by HAL_QueryPlatform instead.
Admin:
  Tested on Raspberry Pi (B rev 1) with various start.elf sizes & versions
  DMA channel reporting only available with latest firmware (i.e. 8th Sep)
  Board revision number read by messaging channel seems to match that returned by /proc/cpuinfo on Linux


Version 0.22. Tagged as 'BCM2835-0_22'

Detail:
  Makefile, s/Display - Deleted on-screen debug code
  hdr/BCM2835, hdr/StaticWS, s/IIC, s/Messaging, s/Stubs, s/Top, s/UART - Strip out calls to on-screen debug code, and a few bits of video code
  s/Video - Video code removed and replaced with stub functions similar to other HALs. Only remaining useful code is HAL_Video_StartupMode, which in time should probably be moved to BCMVideo as well.
Admin:
  Tested on Raspberry Pi with high processor vectors


Version 0.21. Tagged as 'BCM2835-0_21'

        HAL_MachineID functioning correctly
Admin:


Version 0.15. Tagged as 'BCM2835-0_15'

Detail:
	HAL_Reset now causes a complete reboot of the machiine. It isnt yet properly called from
	the kernel.. I've not investigated why yet. Behaviour tested using OS_Hardware call

	HAL_MachineID, with the github start.elf from 18 July 2012 will provide a valid MAC address ..
	i.e. that specific to this machine. The a1 value in HAL_ExtendedID needs to be set 0 for this to be reported
	by OS_ReadSysInfo .. unfortunately, again at this stage, it stalls the boot when set 0, so just for now
	the committed value for a1 in HAL_ExtendedID is not 0 .

	centralised messaging routine added. This is used a fair bit in acquiring the operating environment
	Not yet used in the DMA stuff. probably ought to be. At present the messaging channel this mainly
	handles is not complete, so information from this code is still WIP

Admin:
  (highlight level of testing that has taken place)
  (bugfix number if appropriate)


Version 0.14. Tagged as 'BCM2835-0_14'