Update CHANGELOG and cross compilation section of README

CHANGELOG.md

@@ -39,6 +39,18 @@
   with explicit id attribute 1. Explict id must leave space for the hidden type
   field, but id 1 is valid since id 0 is valid for the type field id. (#271).
 - Add C23 support for "pstdbool.h" header.
+- Fix strict aliasing UB. In the vast majority of cases `*(T *)p` style
+  memory access is supported by compilers, but as of this writing, at least
+  arm-none-eabi with gcc -O2 -mcpu=cortex-m7 will default to an aggressive
+  optimization that leads to uninitialized stack access when not adding
+  -fno-strict-aliasing. Other testet targets, incl. m0 and m1, and compilers, do
+  no exhibit this behaviour at this point time. For more details see
+  `include/flatcc/portable/pmemaccess.h` and `include/flatcc/flatcc_accessors.h`
+  (`_read`, `_write`)`. Flatcc never guaranteed strict aliasing but it appears
+  to be more robust now. Note that the default is still pointer casts on x86/64
+  to avoid performance hits and because it is not usually a problem.
+  It should also be noted that observed issue is with a literal buffer array
+  on local stack. The issue is less likely with dynamically allocated memory. (#274).
 
 ## [0.6.1]
 

README.md

@@ -2333,19 +2333,21 @@ Docker image:
 Users have been reporting some degree of success using cross compiles
 from Linux x86 host to embedded ARM Linux devices.
 
+For this to work, `FLATCC_TEST` option should be disabled in part
+because cross-compilation cannot run the cross-compiled flatcc tool, and
+in part because there appears to be some issues with CMake custom build
+steps needed when building test and sample projects.
+
 2024-03-08: WARNING:
 -O2 -mcpu=cortex-m7 targets using the arm-none-eabi 13.2.Rel1 toolchain
 can result in uninitialized stack access when not compiled with
 `-fno-strict-aliasing`
 -mcpu=cortex-m0 and -mcpu=cortex-m1 appears to be unaffected.
 See also [issue #274](https://github.com/dvidelabs/flatcc/issues/274).
+2024-10-03: Fix available on flatcc master branch when you read this.
+See also CHANGELOG comments for release 0.6.2.
 
 
-For this to work, `FLATCC_TEST` option should be disabled in part
-because cross-compilation cannot run the cross-compiled flatcc tool, and
-in part because there appears to be some issues with CMake custom build
-steps needed when building test and sample projects.
-
 The option `FLATCC_RTONLY` will disable tests and only build the runtime
 library.