Picolibc is a set of standard C libraries, both libc and libm, designed for smaller embedded systems with limited ROM and RAM. Picolibc includes code from Newlib and AVR Libc. Picolibc has been tested on RISC-V and ARM processors.
Picolibc was previously named newlib-nano, but that name has another definition within newlib and so the Picolibc name was adopted instead.
I've written a presentation for Linaro Connect and the Embedded Linux Conference. I wrote complete notes to go with the slides, so I've uploaded the slides and notes here.
These packages are designed to be used with specific versions of the GNU Arm Embedded Toolchain. Get the zip file for the version matching the toolchain you have installed.
First, download and install the GNU Arm Embedded Toolchain. Next, download the matching Picolibc zip file. Then, unpack the Picolibc zip file “on top” of the GNU Arm Embedded Toolchain. This is done most easily by opening up a command prompt window and using a zip file extractor to overlay the picolibc bits on top of the GNU Arm Embedded Toolchain bits.
On Windows, you can use the 7-Zip command line tool, 7z. If the Picolibc zip file is in c:\Users\keithp\Downloads\picolibc-1.6-10-2020-q4-major.zip, and the GNU Arm Embedded Toolchain is installed in c:\Program Files (x86)\GNU Arm Embedded Toolchain\10 2020-q4-major, then you'd type: