[PATCH] This patch provides usage of RTEMS cross-compiler over GCC cross-compiler

[utkarsh.rai60 at gmail.com]

Really sorry for a new patch, I somehow rm -rf'ed my machine's root
---
 user/start/tools.rst | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/user/start/tools.rst b/user/start/tools.rst
index c3f039b..3bb939e 100644
--- a/user/start/tools.rst
+++ b/user/start/tools.rst
@@ -76,3 +76,19 @@ source code used.
 
 
 Add ``--verbose`` to the GCC command for the the verbose version details.
+
+Need for RTEMS-Specific Cross-Compiler
+--------------------------------------------
+  New users are often confused as to why they can't use their distribution's cross-compiler for their target on rtems, e.g.,the riscv64-linux-gnu or the arm-none-eabi-gcc. Below mentioned are some of the reasons for using the RTEMS cross-compiler.
+
+ ``Correct configuration of newlib`` -
+    Newlib is a C standard library implementation intended for use on embedded systems. Most of the POSIX and libc support for RTEMS is derived from newlib. The RTEMS cross-compiler configures newlib correctly for RTEMS.
+
+ ``Threading in GCC support libraries`` -
+    GCC support threading libraries such as ``pthread.h`` provide threading support to an application; these libraries are tailored according to RTEMS using the RTEMS cross-compiler.
+   
+ ``Provide preprocessor define __rtems__`` -
+    The ``__rtems__`` preprocessor define is used to provide conditional code compilation in source files that are shared with other projects e.g. in newlib or imported code from freebsd.
+
+ ``Multilib variants to match the BSP``-
+    RTEMS configures GCC to create separate runtime libraries for each supported instruction set, floating point unit, vector unit, word size (e.g. 32-bit and 64-bit), endianness, ABI, processor errata workarounds,and so on in the architecture. These libraries are termed multilib variants. Multilibs variants to match the BSP are set by selecting a specific set of machine options using the RTEMS cross-compiler.
-- 
2.17.1