Yesterday the Raspberry Pi foundation committed a change to the firmware repository which makes this new option the default and so it became necessary to test the change for compatibility with Ultibo, tests showed that the new memory map presented was not compatible with the default page table allocation strategy and required a small change in order to prevent boot failure.
The same commit to the firmware also contained a change to the ARM stub to halt all secondary CPUs using the WFE instruction during boot, this change (while not fatal to Ultibo) also required a small addition to the boot process in order to correctly handle the new behavior.
Changes to Ultibo core have now been committed to address both of these issues, you should note the following:
- These changes only relate to Raspberry Pi 2 and 3, there is no affect or impact on the Raspberry Pi A, B, A+ ,B+ or Zero
- These changes apply to firmware dated 29 July 2017 (Revision 597B9B66) or later, in earlier releases the total_mem=1024 option had to be enabled manually
- The changes to Ultibo core are compatible with both old and new versions of the firmware
- The additional 16MB can be made available to either the GPU (default) or to Ultibo, see this discussion for further information
For details of how to apply the latest source to your Ultibo core installation and rebuild your run time library see the wiki page Building from Source or watch the Building the RTL video on YouTube.