Expaned boards.txt.py to allow new MMU options and create revised .ld's
Updated eboot to pass 48K IRAM segments.
Added Cache_Read_Enable intercept to modify call for 16K ICACHE
Update platform.txt to pass new mmu options through to compiler and linker preprocessor.
Added quick example: esp8266/MMU48K

Added MMU_ qualifier to new defines.
Moved changes into their own file.
Don't know how to fix platformio issue.

Updated tools/sizes.py to report correct IRAM size and indicate ICACHE size.
Merged in earlephilhower's work on unaligned exception. Refactored and added
support for store operations and changed the name to be more closely aligned
with its function. Improved crash reporting path.

Added some inline functions to aid in byte and short access to iRAM.
 * only byte read has been tested
Updated .ld file to work better with platform.io; however, I am still
missing some steps, so platformio will still fail.

master was missing new additions added by boards.txt.py in the PR.
Which the CI flags when it rebuilds boards.txt.

Adapted changes to umm_malloc, Esp.cpp, StackThunk.cpp,
WiFiClientSecureBearSSL.cpp, and virtualmem.ino to irammem.ino from
@earlephilhower PR esp8266#6994.

Reworked umm_malloc to use context pointers instead of copy context.
umm_malloc now supports allocations from IRAM. Added class
HeapSelectIram, ... to aid in selecting alternate heaps,
modeled after class InterruptLock.
Restrict alloc request from ISRs to DRAM.

Never ending improvements to debug printing.

Sec Heap option now pulls in free IRAM left over in the 1st 32K block.
Managed through umm_malloc with HeapSelectIram.

Updated examples.

Don't know what to do with platformio it doesn't like my .S file.
ifdef out USE_ISR_SAFE_EXC_WRAPPER to block the new assemlby module
from building on platformio only.

@mcspr, Thankyou!

…cking IRAM size.

…to poc-cache-config

…to poc-cache-config

… UMM_STATS_FULL was used.

…6K ICACHE.

… DRAM total.

Option UMM_INLINE_METRICS requires additional edits before it can
be used.

Corrected some UMM_POSION missed edits.

Several fixes and improvements to example MMU48K.

With the improved optimization in toolchain 10.1 The example divide by 0
exception was failing with a HWDT event instead of its exception handler.
The compiler saw the obscured divide by 0 and replaced it with a break point.

…ler.

GDBSTUB definitions are different from the BootROM's.

Co-authored-by: Max Prokhorov <[email protected]>

Changed mmu related usages of ETS_... defines to DBG_MMU_...

Cleanup in example MMU48K.ino. Removed stale memory reference macro
and mmu_status print statement. Cleanup printf '\n' to be '\r\n'.

Improved issolation of development debug prints from the rest of the debug prints.

Updated example HeapMetric.ino to also illustrate use of IRAM
Improved comments in exc-c-wrapper-handler.S. Added insurance IRQ disable.

Improved function name uniqueness for is_iram, is_dram, and is_icache by
adding prefix mmu_. Also, made them available outside of a debug build.
Made pointer precision width more specific.

Made some of the static inline functions in mmu_irm.h safe for ISRs by
setting then for always inline.

Extended use 'umm_heap_context_t *_context' argument in ..._core functions
and expanded its usage to reduce unnecessary repeated calls to
umm_info(NULL, false), also removed recursion from umm_info(NULL, true).

Fixed stack buffer length in umm_info_safe_printf_P and heap.cpp.

Added example for creating an IRAM reserve section.

Updated mmu.rst. Grammar and spelling corrections.

…nt was discarded.

…48K.ino

…to poc-cache-config

Good test catch.

Add updated boot.elf created with merge content.

…all.

Use the replacement wrapper on non32xfer_exception_handler install.

Added comments to code describing some exception handling issues.

rebuilt eboot.elf

resolved conflicts in boards.txt.py and platform.txt

Resolved boards.txt conflict.

Limited access to some detailed typdefs/prototypes to .cpp
modules, to avoid future build conflicts.

Completed TODO for verifing that the "C" structure struct __exception_frame
matches the ASM version.

Fixed some typo's, code rot, and added some more cases in examaple irammem.ino.
Refactored a little and reordered printing to ease comparison between methods.

Corrected `#ifdef __cplusplus` coverage area. Cleaned up `extern "C" ...` usage.
Fixes issues with including mmu_iram.h or esp8266_undocumented.h in .c files.

Some comment tuning.

In the context of _xtos_set_exception_handler and the functions it registers,
changed to type int for exception cause type. This is also the type used by gdbstub
and some other Xtensa files I found.