ARM: Core Stack Improvements/Bug fixes for 2.1 release

[ioannisg]

This is an umbrella issue for the ARM stack enhancements, including improvements/enhancements made for ARM SoCs and Boards, beyond 2.0 and towards the 2.1 release.

Several of the items below are related to issues, which have been spotted before and during the 2.0 feature freeze and tree stabilization, and have, eventually, been moved to the 2.1 Zephyr release.

Items are constantly been added in the list, as issues are been reported and fixed. This will give a quick overview of the implemented fixes/improvements and help with the ARM release notes.

Areas:

• ARM stack
• ARM SoCs, Boards, Drivers
• Kernel interface to arch
• Memory protection related tests

Scope

• Optimizations
• Coverage
• Feature enhancements
• Bug fixes / Workarounds (or workaround removals, if applicable)
• Clean-up, refactoring

Below is a list of tasks:

• [Bug ARM] Support for memory protection features in baseline cores (M0+ and M23) (ARM Memory Protection functions not invoked in SWAP for ARMv6/ARMv8-M Baseline #12961, Supporting User Mode on ARM Cortex-M Baseline #19689, Arch arm assembly simplifications #19794, boards: arm: nucleo_g071rb: include MPU in HW features #20074 )
• [Enh. Bug ARM] Misc bug-fixes and improvements (arch: arm: userspace: minor refactor in z_arch_is_user_context #17189, Test arch arm thread swap minor fix #19310, tests: arm thread swap: increase Idle Stack size for no-opt test-case #19318, arch: arm: clean up inclusions in assembly files #19709, tests: kernel: userspace: replace inline assembly with C code #19822, arch: arm: error: fix ARMv6-M assembly for Z_ARCH_EXCEPT #19825, tests: arch: arm: increase main stack size for no-opt interrupt test #20215, arch: arm: Inline arch_isr_direct_header. #20446 , headers: Refactor kernel and arch headers. #20119, arch: arm: Make PLATFORM_SPECIFIC_INIT available to all ARM variants. #20468 )
• [Enh. ARM] Update CMSIS headers to version 5.6 (ext: hal: cmsis: Update ARM CMSIS headers to version 5.6.0 #19286)
• [Enh. ARM] Non-overlapping MPU gap-filling needs to be optional (non-overlapping MPU gap-filling needs to be optional #19067)
• [Enh. ARM] QEMU for ARMv6-M (Add qemu_cortex_m0/m0+ board. #2686)
• [Enh. ARM] ARM code naming cleanup (arm: arch code naming cleanup #19491)
• [Enh. ARM] Make ARM Thread Swap test run for Cortex-M0 (Test arm thread swap extend to cortex m0 #19572)
• [Ehn. ARM] Make ARM IRQ Vector Table test run for ARMv6-M (Tests arch arm irq vector table fix for armv6 #19856)
• [Enh. ARM] Re-work z_arm_is_in_isr and API for nested exception (Arch arm fix is in isr #19688)
• [Bug ARM] Clobber list in z_arch_switch_to_main_thread() (Inline assembly in Arm z_arch_switch_to_main_thread missing clobber list #16900, arch: arm: protect r0 in z_arch_switch_to_main_thread() inline ASM #20094)
• [Enh. ARM] Cortex-R enhancements for 2.1 (Refactor and fix Cortex-R device tree #19696, Cortex-R Port Improvement for 2.2 #19698 )

[andrewboie]

@ioannisg please consider adding #19067 to the list.
I can take a look at implementing it if you don't have the bandwidth.

[ioannisg]

@ioannisg please consider adding #19067 to the list.
I can take a look at implementing it if you don't have the bandwidth.

You're right @andrewboie that one should be in for 2.1. I 'll include it.

[ioannisg]

Unfinished issues moved to #21201