Libraries and Floating Point Support Guide

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Libraries and Floating Point Support Guide

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The ARM C and C++ libraries

Mandatory linkage with the C library

C and C++ runtime libraries

C and C++ library features

Library heap usage requirements of the ARM C and C

Compliance with the Application Binary Interface (

Increasing portability of object files to other CL

ARM C and C++ library directory structure

Selection of ARM C and C++ library variants based

Thumb C libraries

C++ and C libraries and the std namespace

ARM C libraries and multithreading

ARM C libraries and reentrant functions

ARM C libraries and thread-safe functions

Use of static data in the C libraries

Use of the __user_libspace static data area by the

C library functions to access subsections of the _

Re-implementation of legacy function __user_libspa

Management of locks in multithreaded applications

How to ensure re-implemented mutex functions are c

Using the ARM C library in a multithreaded environ

Thread safety in the ARM C library

Thread safety in the ARM C++ library

The floating-point status word in a multithreaded

Using the C library with an application

Using the C and C++ libraries with an application

Using $Sub$$ to mix semihosted and nonsemihosted I

Using the libraries in a nonsemihosting environmen

C++ exceptions in a non-semihosting environment

Direct semihosting C library function dependencies

Indirect semihosting C library function dependenci

C library API definitions for targeting a differen

Building an application without the C library

Creating an application as bare machine C without

Integer and floating-point compiler functions and

Bare machine integer C

Bare machine C with floating-point processing

Customized C library startup code and access to C

Program design when exploiting the C library

Using low-level functions when exploiting the C li

Using high-level functions when exploiting the C l

Using malloc() when exploiting the C library

Tailoring the C library to a new execution environ

How C and C++ programs use the library functions

Initialization of the execution environment and ex

C++ initialization, construction and destruction

Legacy support for C$$pi_ctorvec instead of .init_

Exceptions system initialization

Emergency buffer memory for exceptions

Library functions called from main()

Program exit and the assert macro

Assembler macros that tailor locale functions in t

Link time selection of the locale subsystem in the

ISO8859-1 implementation

Shift-JIS and UTF-8 implementation

Runtime selection of the locale subsystem in the C

Definition of locale data blocks in the C library

LC_CTYPE data block

LC_COLLATE data block

LC_MONETARY data block

LC_NUMERIC data block

LC_TIME data block

Modification of C library functions for error sign

Modification of memory management functions in the

Avoiding the heap and heap-using library functions

C library support for memory allocation functions

Heap1, standard heap implementation

Heap2, alternative heap implementation

Using a heap implementation from bare machine C

Stack pointer initialization and heap bounds

Defining __initial_sp, __heap_base and __heap_limi

Extending heap size at runtime

Legacy support for __user_initial_stackheap()

Tailoring input/output functions in the C and C++

Target dependencies on low-level functions in the

The C library printf family of functions

The C library scanf family of functions

Redefining low-level library functions to enable d

The C library functions fread(), fgets() and gets(

Re-implementing __backspace() in the C library

Re-implementing __backspacewc() in the C library

Redefining target-dependent system I/O functions i

Tailoring non-input/output C library functions

Real-time integer division in the ARM libraries

Selecting real-time division in the ARM libraries

How the ARM C library fulfills ISO C specification

mathlib error handling

ISO-compliant implementation of signals supported

ISO-compliant C library input/output characteristi

Standard C++ library implementation definition

C library functions and extensions

Persistence of C and C++ library names across rele

Link time selection of C and C++ libraries

Managing projects that have explicit C or C++ libr

Compiler generated and library-resident helper fun

C and C++ library naming conventions

Using macro__ARM_WCHAR_NO_IO to disable FILE decla

The ARM C micro-library

Floating-point support

Bare machine integer C

ARM Compiler toolchain v5.02 for µVision Using ARM C and C++ Libraries and Floating-Point Support

Home > The ARM C and C++ libraries > Bare machine integer C

Bare machine integer C

If you are writing a program in C that does not use the library and is to run without any environment initialization, you must:

Re-implement __rt_raise() if you are using the heap.
Not define main(), to avoid linking in the library initialization code.
Write an assembly language veneer that establishes the register state required to run C. This veneer must branch to the entry function in your application.
Provide your own RW/ZI initialization code.
Ensure that your initialization veneer is executed by, for example, placing it in your reset handler.
Build your application using --fpu=none.

When you have met these requirements, link your application normally. The linker uses the appropriate C library variant to find any required compiler functions that are implicitly called.

Many library facilities require __user_libspace for static data. Even without the initialization code activated by having a main() function, __user_libspace is created automatically and uses 96 bytes in the ZI segment.

See also

Tasks

Building an application without the C library.

Concepts

Reference

--fpu=name.

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