Kernel standard library

Xelix has a minimal standard library in src/lib. It implements a subset of C stdlib functionality as well as a number of Xelix-specific functions.

The lib directory is part of the include path, so src/lib/string.h can be included using #include <string.h>.

Function overview

Header Functions
bitmap.h bit_set, bit_clear, bit_toggle, bit_get, bitmap_index, bitmap_offset, bitmap_size, bitmap_get, bitmap_set, bitmap_clear, bitmap_find, bitmap_count
cmdline.h cmdline_get, cmdline_get_bool
endian.h endian_swap16, endian_swap32, endian_swap64
errno.h sc_errno
kavl.h kavl_insert, kavl_find, kavl_erase, kavl_erase_first, kavl_itr_first, kavl_itr_find, kavl_itr_next, kavl_at, KAVL_INIT, KAVL_INIT2
panic.h assert, assert_nc, addr2name, panic
printf.h printf, sprintf, snprintf, vsnprintf, vprintf, fctprintf
spinlock.h spinlock_release, spinlock_cmd, spinlock_get
stdlib.h atoi, is_digit
string.h strdup, strcmp, strcasecmp, strncasecmp, strncmp, strcat, strcpy, strncpy, strlen, strndup, memset, memcpy, memcmp, memmove, strchr, bzero, strtok_r, substr, find_substr, asprintf, memset32
time.h time_get, time_get_timeval, sleep, uptime
variadic.h variadic_call

Kernel logger

src/lib/log.c contains the kernel logger. It outputs messages to display and serial and stores them in a kernel buffer. Output can also be configured depending on severity.

void log(uint32_t level, const char *fmt, ...);

Available log levels: LOG_DEBUG, LOG_INFO, LOG_WARN, LOG_ERR. Debug messages are not stored in the kernel buffer.

Note that before kmalloc is initalized, the logger uses a fixed-size buffer of 0x1000 bytes which can run out. It switches to an automatically growing dynamic buffer after memory initialization.

On a running Xelix system, log messages can be inspected using the xelix-utils dmesg tool. They can also be read directly from /sys/log with raw timestamps.

Kernel command line

src/lib/cmdline.c contains a simple kernel command line parser. It retrieves a command line of the format root=/dev/ide1p1 init=/usr/bin/bash from Multiboot and makes the individual entries available using

char* cmdline_get(const char* key);
bool cmdline_get_bool(const char* key);