avr_minimal_runtime | Building AVR without C runtime , stdlibs

avr_minimal_runtime is a C library typically used in Internet of Things (IoT) applications. avr_minimal_runtime has no bugs, it has no vulnerabilities and it has low support. You can download it from GitHub.

When building AVR firmwares using avr-gcc it automatically links them with avr-libc and c runtime, which provides a lot. This repo builds an AVR firmware for atmega8 without support from C runtime. Each source file gets compiled into an object file, which are afterwards linked using a custom linker script to achieve correct memory layout. Things that runtime.s does: - sets up a stack pointer to last available address in SRAM - copies .data from flash to SRAM - calls main() from main.s. vectors.s sets up a vector table, main.s provides a main function and some basic static variables to be copied in runtime.s m8def.in is a file to be included by other source files, contains defines for IO registers and memory sizes for atmega8a (taken from datasheet). build with "make all", clear with "make clear". // TODO:Explain in detail atmega8 boot process, memory layout etc. in this README with code references.