libkernaux ========== Auxiliary library for kernel development. Table of contents ----------------- * [Overview](#libkernaux) * [Table of contents](#table-of-contents) * [API](#api) * [Tips](#tips) * [Compilation](#compilation) * [Cross-compilation](#cross-compilation) * [Portability](#portability) * [Discussion](#discussion) API --- * [Measurement units utils](/include/kernaux/units.h) *(work in progress)* * [Simple command line parser](/include/kernaux/cmdline.h) * [Multiboot 2 (GRUB 2) information parser](/include/kernaux/multiboot2.h) * [Serial console](/include/kernaux/console.h) * [Page Frame Allocator](/include/kernaux/pfa.h) *(work in progress)* * [ELF utils](/include/kernaux/elf.h) *(work in progress)* * [Architecture-specific helpers](/include/kernaux/arch/) * [printf replacement](/include/kernaux/printf.h) *(work in progress)* * [stdlib replacement](/include/kernaux/stdlib.h): * `memset` * `strlen` * `strncpy` * `itoa` *(work in progress)* Tips ---- ### Compilation ``` ./autogen.sh ./configure make sudo make install ``` You can test with `make check`. This is just a usual library. You can use most of it's APIs in hosted environment. ### Cross-compilation Create configuration script with `./autogen.sh`. Configure with [cross-compiler](https://wiki.osdev.org/GCC_Cross-Compiler) in `$PATH` to make without it in `$PATH`: ``` ./configure \ --host='i386-elftailix' \ AR="$(which i386-elftailix-ar)" \ CC="$(which i386-elftailix-gcc)" \ RANLIB="$(which i386-elftailix-ranlib)" \ CFLAGS='-ffreestanding -nostdlib -fno-builtin -fno-stack-protector' ``` You can see the following messages. It's [a bug](https://savannah.gnu.org/support/index.php?110393) in **autoconf**, just ignore it. ``` checking for _Bool... no checking stdarg.h usability... no checking stdarg.h presence... yes configure: WARNING: stdarg.h: present but cannot be compiled configure: WARNING: stdarg.h: check for missing prerequisite headers? configure: WARNING: stdarg.h: see the Autoconf documentation configure: WARNING: stdarg.h: section "Present But Cannot Be Compiled" configure: WARNING: stdarg.h: proceeding with the compiler's result configure: WARNING: ## ---------------------------------------------------------- ## configure: WARNING: ## Report this to https://github.com/tailix/libkernaux/issues ## configure: WARNING: ## ---------------------------------------------------------- ## checking for stdarg.h... no checking stddef.h usability... no checking stddef.h presence... yes configure: WARNING: stddef.h: present but cannot be compiled configure: WARNING: stddef.h: check for missing prerequisite headers? configure: WARNING: stddef.h: see the Autoconf documentation configure: WARNING: stddef.h: section "Present But Cannot Be Compiled" configure: WARNING: stddef.h: proceeding with the compiler's result configure: WARNING: ## ---------------------------------------------------------- ## configure: WARNING: ## Report this to https://github.com/tailix/libkernaux/issues ## configure: WARNING: ## ---------------------------------------------------------- ## checking for stddef.h... no ``` To install into specific directory use full path: `DESTDIR="$(pwd)/dest" make install` instead of `DESTDIR=dest make install`. When configured with cross-compiler, library can't be build and installed with just `make && sudo make install`. Instead use the following commands: * `make libkernaux.a` * `sudo make install-exec` * `sudo make install-data` Check if compilation targets i386: `objdump -d src/arch/i386.o`. It should output something like this: ``` src/arch/i386.o: file format elf32-i386 Disassembly of section .text: 00000000 : 0: fa cli 1: f4 hlt 2: eb fc jmp 0 00000004 : 4: 0f 20 c0 mov %cr0,%eax 7: c3 ret 00000008 : 8: 0f 20 e0 mov %cr4,%eax b: c3 ret 0000000c : c: 8b 44 24 04 mov 0x4(%esp),%eax 10: 0f 22 c0 mov %eax,%cr0 13: c3 ret 00000014 : 14: 8b 44 24 04 mov 0x4(%esp),%eax 18: 0f 22 d8 mov %eax,%cr3 1b: c3 ret 0000001c : 1c: 8b 44 24 04 mov 0x4(%esp),%eax 20: 0f 22 e0 mov %eax,%cr4 23: c3 ret ``` 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 Discussion ---------- * [Topic on OSDev.org forum](https://forum.osdev.org/viewtopic.php?f=1&t=37958) * [Thread on r/osdev](https://www.reddit.com/r/osdev/comments/k3ueeu/libkernaux_auxiliary_library_for_kernel/)