📝update kernel to R4T5 and allow for more aggressive memory footprint…

… reduction methods

README.md

@@ -155,7 +155,7 @@ This software is **triple-licensed**: it is either **[LGPL v3](LICENSE.md)** or
 
     Flash and SRAM consumption is calculated in kB, while the other figures are calculated in CPU clock cycles. All values listed in the table below are **typical** (useful system) values, not **minimum** values, because minimum values on system size seldom make any real sense. HAL library are also included in the size numbers.  
 
-    The **absolute minimum** value for RMP is about **1.6k ROM and 432 byte RAM**, which is reached on the HC32L136K8TA (Cortex-M0+) port, and this number even included the 60-byte thread control block and 256-byte stack of the first thread. The OS kernel and the stripped down HAL only consumes **116 bytes** of memory combined. If you are willing to push this limit even further, then the **manufacturer HAL is a rip-off for you** and you can roll your own.  
+    The **absolute minimum** value for RMP is about **1.6k ROM and 432 byte RAM**, which is reached on the HC32L136K8TA (Cortex-M0+) port, and this number even included the 60-byte thread control block and 256-byte stack of the first thread, and a 64-byte kernel interrupt response stack. The OS kernel and the stripped down HAL only consumes **52 bytes** of memory combined. If you are willing to push this limit even further, then the **manufacturer HAL is a rip-off for you** and you can roll your own.  
 
 |Machine      |Toolchain     |Flash|SRAM|Yield|Mail |Sem  |Mail/Int|Sem/Int|Mem  |
 |:-----------:|:------------:|:---:|:--:|:---:|:---:|:---:|:------:|:-----:|:---:|

README_CN.md

@@ -155,7 +155,7 @@ Click **[HERE](README.md)** for English version.
 
   Flash和SRAM消耗以kB计，其他数据以CPU指令周期计。下表列出的所有值都是**典型（有意义的系统配置）值**而非绝对意义上的**最小值**，因为纯技术层面的最小配置在实际工程中很少是真正有用的。HAL库所造成的额外存储器消耗也被计算在内。  
 
-  本系统的**绝对最小值**在**1.6k ROM和432Byte RAM**左右，这个大小是在HC32L136K8TA（Cortex-M0+）的移植上达到的，并包括了第一个线程的60Byte的线程控制块和256Byte的线程栈。操作系统内核和最精简的HAL库一共仅占用了**116Byte**存储。如果你对这个数字还有不满意，那么可以**不使用厂商提供的HAL库**而自己写一个版本。  
+  本系统的**绝对最小值**在**1.6k ROM和432Byte RAM**左右，这个大小是在HC32L136K8TA（Cortex-M0+）的移植上达到的，并包括了第一个线程的60Byte的线程控制块和256Byte的线程栈，以及64Byte的内核中断响应用栈。操作系统内核和最精简的HAL库一共仅占用了**52Byte**存储。如果你对这个数字还有不满意，那么可以**不使用厂商提供的HAL库**而自己写一个版本。  
 
 |架构          |工具链        |Flash|SRAM|Yield|Mail |Sem  |Mail/Int|Sem/Int|Mem  |
 |:-----------:|:------------:|:---:|:--:|:---:|:---:|:---:|:------:|:-----:|:---:|