libkernaux ========== [![Test](https://github.com/tailix/libkernaux/actions/workflows/test.yml/badge.svg)](https://github.com/tailix/libkernaux/actions/workflows/test.yml) Auxiliary library for kernel development. [Topic on OSDev.org forum](https://forum.osdev.org/viewtopic.php?f=1&t=37958). Table of contents ----------------- * [Overview](#libkernaux) * [Table of contents](#table-of-contents) * [API](#api) * [Configuration](#configuration) * [Non-default options](#non-default-options) * [Default options](#default-options) * [Tips](#tips) * [Installation](#installation) * [Development](#development) * [Cross](#cross) * [Architectures](#architectures) * [Portability](#portability) API --- We use [semantic versioning](https://semver.org) for stable APIs. Stable APIs can only change when major version number is increased (or minor while major is zero). Work-in-progress APIs can change at any time. * Runtime environment * Architecture-specific code (*work in progress*) * [Declarations](/include/kernaux/arch/) * [Functions](/include/kernaux/asm/) * [Assertions](/include/kernaux/assert.h) (*stable since* **0.1.0**, *non-breaking since* **0.2.0**) * [Assert: simple](/examples/assert_simple.c) * [Assert: guards](/examples/assert_guards.c) * [Panic: simple](/examples/panic_simple.c) * [Panic: guards](/examples/panic_guards.c) * Stack trace *(planned)* * Device drivers (for debugging only) * [Serial console](/include/kernaux/console.h) (*work in progress*) * [Framebuffer](/include/kernaux/framebuffer.h) (*planned*) * USB (*planned*) * Algorithms * [Simple command line parser](/include/kernaux/cmdline.h) (*stable since* **0.2.0**) * [Example](/examples/cmdline.c) * [Page Frame Allocator](/include/kernaux/pfa.h) (*work in progress*) * [Example](/examples/pfa.c) * Data formats * [ELF](/include/kernaux/elf.h) (*work in progress*) * [Master Boot Record](/include/kernaux/mbr.h) (*work in progress*) * [Multiboot 2 (GRUB 2)](/include/kernaux/multiboot2.h) (*work in progress*) * Stivale 2 (Limine) (*planned*) * Utilities * [Measurement units utils](/include/kernaux/units.h) (*work in progress*) * [To human](/examples/units_human.c) * Usual functions * [libc replacement](/include/kernaux/libc.h) (*stable since* **0.1.0**) * [itoa/ftoa replacement](/include/kernaux/ntoa.h) (*stable since* **0.1.0**) * [printf replacement](/include/kernaux/printf.h) (*stable since* **0.1.0**) * Code from [https://github.com/mpaland/printf](https://github.com/mpaland/printf). Thank you! * [printf](/examples/printf.c) * [vprintf](/examples/printf_va.c) * [snprintf](/examples/snprintf.c) * [vsnprintf](/examples/snprintf_va.c) Configuration ------------- Because this library has no external dependencies, we use **autoconf** features to control behavior of the library, and packages to choose it's components. Configuration options also follow the [semantic versioning](https://semver.org) scheme and are split into stable and work-in-progress ones. Here we cover only stable options. ### Non-default options #### Packages * `--with-libc` - provides the replacement for some standard C functions. Useful in freestanding environment, where no libc is present. You can also separately include or exclude components: * `--with[out]-libc-memset` * `--with[out]-libc-strcpy` * `--with[out]-libc-strlen` * `--with[out]-libc-strnlen` ### Default options #### Features * `--enable-bloat`, disable with `--disable-bloat` * `--enable-float`, disable with `--disable-float` #### Packages All packages all included by default. To exclude all packages except those explicitly included, use `--without-all`. * `--with[out]-ntoa` * `--with[out]-printf` Tips ---- ### Installation ``` ./autogen.sh ./configure CFLAGS='-fPIC' make sudo make install ``` This is just a usual library. You can use most of it's APIs in hosted environment. ### Development ``` ./autogen.sh ./configure --enable-tests CFLAGS='-fPIC' make ``` You can test with `make check`. ### Cross Create configuration script with `./autogen.sh`. Let's assume that your target triplet is `i386-elf`. Configure with [cross-compiler](https://wiki.osdev.org/GCC_Cross-Compiler) in `$PATH` to make without it in `$PATH`: ``` ./configure \ --host='i386-elf' \ --with-libc \ AR="$(which i386-elf-ar)" \ CC="$(which i386-elf-gcc)" \ RANLIB="$(which i386-elf-ranlib)" \ CFLAGS='-ffreestanding -nostdlib -fno-builtin -fno-stack-protector' ``` You can see the following messages. It's [a bug](https://savannah.gnu.org/support/index.php?110393) in **autoconf**, just ignore it. ``` checking for _Bool... no checking stdarg.h usability... no checking stdarg.h presence... yes configure: WARNING: stdarg.h: present but cannot be compiled configure: WARNING: stdarg.h: check for missing prerequisite headers? configure: WARNING: stdarg.h: see the Autoconf documentation configure: WARNING: stdarg.h: section "Present But Cannot Be Compiled" configure: WARNING: stdarg.h: proceeding with the compiler's result configure: WARNING: ## ---------------------------------------------------------- ## configure: WARNING: ## Report this to https://github.com/tailix/libkernaux/issues ## configure: WARNING: ## ---------------------------------------------------------- ## checking for stdarg.h... no checking stddef.h usability... no checking stddef.h presence... yes configure: WARNING: stddef.h: present but cannot be compiled configure: WARNING: stddef.h: check for missing prerequisite headers? configure: WARNING: stddef.h: see the Autoconf documentation configure: WARNING: stddef.h: section "Present But Cannot Be Compiled" configure: WARNING: stddef.h: proceeding with the compiler's result configure: WARNING: ## ---------------------------------------------------------- ## configure: WARNING: ## Report this to https://github.com/tailix/libkernaux/issues ## configure: WARNING: ## ---------------------------------------------------------- ## checking for stddef.h... no ``` To install into specific directory use full path: `DESTDIR="$(pwd)/dest" make install` instead of `DESTDIR=dest make install`. Check if compilation targets i386: `objdump -d src/asm/i386.o`. It should output something like this: ``` src/asm/i386.o: file format elf32-i386 Disassembly of section .text: 00000000 : 0: 0f 20 c0 mov %cr0,%eax 3: c3 ret 00000004 : 4: 0f 20 e0 mov %cr4,%eax 7: c3 ret 00000008 : 8: 8b 44 24 04 mov 0x4(%esp),%eax c: 0f 22 c0 mov %eax,%cr0 f: c3 ret 00000010 : 10: 8b 44 24 04 mov 0x4(%esp),%eax 14: 0f 22 d8 mov %eax,%cr3 17: c3 ret 00000018 : 18: 8b 44 24 04 mov 0x4(%esp),%eax 1c: 0f 22 e0 mov %eax,%cr4 1f: c3 ret ``` Architectures ------------- Architectures should be properly identified. We use the following scheme, but it may change in future: * `x86` * `i386` * `x86_64` * `riscv` * `riscv64` * `arm` - we need more info, now similar to [Debian](https://www.debian.org/ports/arm/) * `armel` * `armhf` * `arm64` Portability ----------- Except GNU/Linux, the library is periodically successfully built (starting with `./autogen.sh`) and tested with **autoconf**, **automake**, **binutils** and **gcc**/**clang** (depending on what is present) on the following operating systems: * FreeBSD 13.0 * Minix 3.3.0 * NetBSD 9.2 * OpenBSD 7.0