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Diffstat (limited to 'docs/process/coding-guidelines.rst')
| -rw-r--r-- | docs/process/coding-guidelines.rst | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/docs/process/coding-guidelines.rst b/docs/process/coding-guidelines.rst index 2c8620d15..ef319e441 100644 --- a/docs/process/coding-guidelines.rst +++ b/docs/process/coding-guidelines.rst @@ -442,6 +442,25 @@ unsigned integer on all systems, cast it to ``unsigned int``. These guidelines should be updated if additional types are needed. +Favor C language over assembly language +--------------------------------------- + +Generally, prefer code written in C over assembly. Assembly code is less +portable, harder to understand, maintain and audit security wise. Also, static +analysis tools generally don't analyze assembly code. + +There are, however, legitimate uses of assembly language. These include: + + - Early boot code executed before the C runtime environment is setup. + + - Exception handling code. + + - Low-level code where the exact sequence of instructions executed on the CPU + matters, such as CPU reset sequences. + + - Low-level code where specific system-level instructions must be used, such + as cache maintenance operations. + -------------- *Copyright (c) 2020, Arm Limited and Contributors. All rights reserved.* |