rtos

以下测试环境为：

• Win10 系统
• 通过 scons --dist 新生成的 qemu 环境
• 每隔 1 秒通过串口 COM9 发送 hello world 的下位机

输入下述命令运行 qemu 程序：

qemu-system-arm -M vexpress-a9 -kernel rtthread.bin --nographic -serial mon:stdio -serial COM9

结果显示系统崩溃，并且是在 qemu 接收第一个字节后崩溃。

下位机不主动发送数据给上位机时，工作正常。

Is your enhancement proposal related to a problem? Please describe.
access_addr always seems to be of size 4; that should be #defined.
crc_init always seem to be of size 3; that should be #defined.

https://github.com/zephyrproject-rtos/zephyr/pull/31009/files#r736229677
https://github.com/zephyrproject-rtos/zephyr/pull/31009/files#r736229386

Describe the solution you'd like
A

Motivation

Previous discussion: #1500

Details

Currently, there is no workflow to build and test rust-related crates on the Windows platform. So there is no guarantee for making sure the compilation and functionality are working.

In PROTECTED mode, the MPU is used to map regions of memory to supervisor- and/or user-accessible memory. Currently, that algorithm is very simple: The entire address range is made accessible in supervisor mode; a single MPU region is used to enable user-mode access in each user memory region.

Each MPU region must bit both of a power-of-two size and with an alignment in memory equal to the si

With aligned_alloc() in the C11 standard, free() is called to free memory, rather than an equivalent aligned_free().

We should update our library with some logic that can be used to correctly call aligned_free() if free() is used instead.