Release v2021.4.0

We are pleased to integrate a lot of fixes and improvements in the SO3 kernel. This set of changes mainly concern system and device management.


• Improvements of fdt parsing and file organization
• Revisited device model based on devclass with private structure
• Improvements of initcall processing, adding post_initcall
• Fixed numerous bugs in cache handling especially on Cortex-A72
• Simplified model of the MMU configuration at bootstrap
• Added support of rpi 4 Sense-hat extension
• Added post-init initcall for late initialization
• 64 KB Stack size of all threads
• Fixed bugs related to process loading and page list management
• Fixed bugs in frame table management

A new set of changes concerning new features will come up very shortly.