libc Archives - Page 2 of 2 - Embedded Artistry

31 March 201721 April 2020

musl libc

musl libc is a free, lightweight libc implementation intended for use on embedded systems. musl weighs in at 462kB for a full .a library (compared to glibc's 2MB), making musl an attractive option. (See the libc comparison data here) If you need a complete libc implementation for your system, this is an excellent place to …

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29 March 201715 December 2021

Libc Bringup: String Functions

Continuing with our libc bringup, it’s time to tackle some of the string functions: strcpy strncpy strlen strcmp strncmp strstr strdup I also want to support the FreeBSD functions below: strnlen strnstr strndup These functions have been used on many systems I’ve worked on, and they provide a valuable basis to start from when working …

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23 March 201721 April 2020

Announcing libc on embedded-resources

I have added an example libc implementation to the embedded-resources repository. This libc example is not complete, but will be improved and expanded upon as I work on this website. Most embedded systems that I work on are resource constrained. My typical approach when bringing up a new system is to use a minimal set …

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22 March 201715 December 2021

memset, memcpy, memcmp, and memmove

We need to knock out many more libc functions before we can start with our C++ runtime bringup. Today we’ll tackle the mem* funtions: memcmp memcpy memmove memset These functions are vital for our system and are used throughout the standard libaries (e.g. calloc, realloc). These functions are also used during the startup process, when …

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22 February 20179 October 2024

Generating Aligned Memory

Embedded systems often have requirements for pointer alignment. These alignment requirements exist in many places, some including: General device/CPU requirements Unaligned access may generate a processor exception with registers that have strict alignment requirements Cache line size You don’t want to accidentally perform clean/invalidate operations on random data Peripheral hardware requirements DMA and USB peripherals …

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17 February 201715 December 2021

Implementing Malloc with ThreadX

I previously provided a free-list malloc implementation. In this article, you will see how to use an RTOS with a memory allocator to build malloc and free. Table of Contents ThreadX Creating a Byte Pool Allocating Memory Freeing Memory Initialization malloc free Hiding the Initialization Functions Pointers & Atomics Memory Definition Malloc as a Function …

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15 February 201714 March 2022

Implementing Malloc: First-fit Free List

Now that we’ve seen some useful C++ examples that can be applied to embedded systems, you’re probably curious about getting C++ code up and running on your embedded platform. If you try linking C++ code for your platform, you might find that you have numerous undefined symbol errors. Unfortunately, C++ runtimes are not provided for …

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