kernel: add some basic features

+ feat list:
+ * gdt/idt
+ * brokie pmm

kernel/src/lib/ansi.c

@@ -0,0 +1,29 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  ansi.c - ANSI escape sequence generation functions implementation.
+ */
+
+#include <deps/npf.h>
+#include <lib/ansi.h>
+#include <stdint.h>
+
+static char __ansi_bg_buf[32];
+static char __ansi_fg_buf[32];
+
+char *ansi_gen_bg(uint8_t r, uint8_t g, uint8_t b) {
+    int len = npf_snprintf(__ansi_bg_buf, sizeof(__ansi_bg_buf), "\033[48;2;%d;%d;%d;m", r, g, b);
+    if (len < 0 || len >= (int)sizeof(__ansi_bg_buf)) {
+        return "\033[0m";
+    }
+    return __ansi_bg_buf;
+}
+
+char *ansi_gen_fg(uint8_t r, uint8_t g, uint8_t b) {
+    int len = npf_snprintf(__ansi_fg_buf, sizeof(__ansi_fg_buf), "\033[38;2;%d;%d;%d;m", r, g, b);
+    if (len < 0 || len >= (int)sizeof(__ansi_fg_buf)) {
+        return "\033[0m";
+    }
+    return __ansi_fg_buf;
+}

kernel/src/lib/ansi.h

@@ -0,0 +1,15 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  ansi.h - ANSI escape sequence generation functions.
+ */
+
+#pragma once
+#include <stdint.h>
+
+#define ANSI_CLEAR_SCREEN "\033[H\033[2J"
+#define ANSI_RESET_COLOR  "\033[39m\\033[49m"
+
+char *ansi_gen_bg(uint8_t r, uint8_t g, uint8_t b);
+char *ansi_gen_fg(uint8_t r, uint8_t g, uint8_t b);

kernel/src/lib/log.c

@@ -0,0 +1,53 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  log.c - Kernel logging interface.
+ */
+#include <stdarg.h>
+#include <lib/log.h>
+
+static int __logger_max_loglevel = 0;
+static log_output_func __logger_outputs[16];
+static int __logger_output_count = 0;
+
+static char* prelog[7] = {
+    "\033[38;2;169;68;66;mFAULT  | \033[39m",
+    "\033[38;2;217;83;79;mERROR  | \033[39m",
+    "\033[38;2;240;173;78;mWARN   | \033[39m",
+    "\033[38;2;240;240;240;mNOTICE | \033[39m",
+    "\033[38;2;92;184;92;mINFO   | \033[39m",
+    "\033[38;2;87;201;193;mDEBUG  | \033[39m",
+    "\033[38;2;150;150;150;mTRACE  | \033[39m",
+};
+
+void log_init(int max_loglevel) {
+    __logger_max_loglevel = max_loglevel;
+}
+
+bool log_register_output(log_output_func fn) {
+    if (fn && __logger_output_count <= 16) {
+        __logger_output_count ++;
+        __logger_outputs[__logger_output_count - 1] = fn;
+        return true;
+    }
+    return false;
+}
+
+void log(int loglevel, char *str, ...) {
+    if (__logger_max_loglevel == 0 || __logger_output_count == 0)
+        return; // The user forgot to initialize the logger.
+
+    if (loglevel > __logger_max_loglevel)
+        return; // The user does not want this type of log to show up.
+
+    va_list vl;
+    va_start(vl, str);
+
+    for (int i = 0; i < __logger_output_count; i++) {
+        __logger_outputs[i](prelog[loglevel - 1], (void*)0);
+        __logger_outputs[i](str, &vl);
+    }
+
+    va_end(vl);
+}

kernel/src/lib/log.h

@@ -0,0 +1,35 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  log.h - Kernel logging interface.
+ */
+
+#pragma once
+
+// Log levels in order of increasing severity
+#include <stdarg.h>
+#include <stdbool.h>
+
+#define LOGLEVEL_TRACE    7
+#define LOGLEVEL_DEBUG    6
+#define LOGLEVEL_INFO     5
+#define LOGLEVEL_NOTICE   4
+#define LOGLEVEL_WARNING  3
+#define LOGLEVEL_ERROR    2
+#define LOGLEVEL_FATAL    1
+
+typedef void(*log_output_func)(char *str, va_list *vl);
+
+void log_init(int max_loglevel);
+bool log_register_output(log_output_func fn);
+void log(int loglevel, char *str, ...);
+
+// Shortcuts to log
+#define trace(str, ...)   log(LOGLEVEL_TRACE,  str, ##__VA_ARGS__)
+#define debug(str, ...)   log(LOGLEVEL_DEBUG,  str, ##__VA_ARGS__)
+#define info(str, ...)    log(LOGLEVEL_INFO,   str, ##__VA_ARGS__)
+#define notice(str, ...)  log(LOGLEVEL_NOTICE, str, ##__VA_ARGS__)
+#define warn(str, ...)    log(LOGLEVEL_WARNING, str, ##__VA_ARGS__)
+#define error(str, ...)   log(LOGLEVEL_ERROR,  str, ##__VA_ARGS__)
+#define fatal(str, ...)   log(LOGLEVEL_FATAL,  str, ##__VA_ARGS__)

kernel/src/lib/logoutputs_sk.c

@@ -0,0 +1,26 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  logoutputs_sk.c - Output functions for the logger
+ */
+#include "deps/npf.h"
+#include <dev/tty.h>
+#include <lib/logoutputs_sk.h>
+
+void sklogoutput_tty(char *str, va_list *vl) {
+    if (!vl) {
+        tty_puts(str);
+        return;
+    }
+
+    char buf[2048];
+    npf_vsnprintf(buf, 2048, str, *vl);
+    tty_puts(buf);
+}
+
+void sklogoutput_e9(char *str, va_list *vl) {
+    // TODO: implement this
+    (void)str;
+    (void)vl;
+}

kernel/src/lib/logoutputs_sk.h

@@ -0,0 +1,16 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  logoutputs_sk.h - Output functions for the logger
+ */
+
+#pragma once
+
+// Output to the terminal.
+#include <stdarg.h>
+
+void sklogoutput_tty(char *str, va_list *vl);
+
+// Output to QEMU & Bochs's E9 port.
+void sklogoutput_e9(char *str, va_list *vl);

kernel/src/lib/npf.c

@@ -0,0 +1,18 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  npf.c - nanoprintf configuration and implementation.
+ */
+
+#define NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS 1
+#define NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS 0
+#define NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS 1
+#define NANOPRINTF_USE_SMALL_FORMAT_SPECIFIERS 1
+#define NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS 0
+#define NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS 1
+#define NANOPRINTF_USE_WRITEBACK_FORMAT_SPECIFIERS 1
+
+// Compile nanoprintf in this translation unit.
+#define NANOPRINTF_IMPLEMENTATION
+#include <deps/npf.h>

kernel/src/lib/string.c

@@ -1,3 +1,10 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  string.c - String manipulation functions implementation.
+ */
+
 #include <lib/string.h>
 
 size_t strlen(char *str) {

kernel/src/lib/string.h

@@ -1,3 +1,10 @@
+/*
+ *  The Soaplin Kernel
+ *  Copyright (C) 2025 The SILD Project
+ *
+ *  string.h - String manipulation functions.
+ */
+
 #pragma once
 
 #include <stddef.h>