global log mechanism

kernel/acpi/acpi.c

@@ -54,7 +54,7 @@ void read_acpi_tables(const void* rsdp_location) {
 
     size_t n_entries = (xsdt->header.length - sizeof(xsdt->header)) / sizeof(void*);
 
-    kprintf("%u ACPI entries\n", n_entries);
+    klog_debug("%u ACPI entries:", n_entries);
 
     bool madt_parsed = false,
          hpet_parsed = false,
@@ -65,7 +65,7 @@ void read_acpi_tables(const void* rsdp_location) {
         const struct ACPISDTHeader* table = xsdt->entries[i];
         assert(checksum(&table, table->length));
 
-        kprintf("%3u: %4s\n", i, table->signature.arg);
+        klog_debug("  %3u: %4s", i, table->signature.arg);
 
 
         switch(table->signature.raw) {

kernel/debug/logging.c

@@ -4,9 +4,29 @@
 #include "logging.h"
 #include "../video/terminal.h"
 
+#include "../klib/string.h"
+
 #define TEXT_COLOR 0xfff0a0
 
-const char* get_level_names_and_set_terminal_color(unsigned level) {
+#define BUFFER_SIZE 4096
+
+static char buffer[BUFFER_SIZE];
+static unsigned current_level;
+// current position in the buffer
+static int i = 0;
+
+// appends a string to the buffer
+// if there is enough space remaining.
+// else, leave it as is
+static inline void append_string(const char* str) {
+    unsigned len = strlen(str);
+    if(i+len >= BUFFER_SIZE)
+        return;
+    memcpy(buffer+i, str, len);
+    i += len;
+}
+
+static const char* get_level_names_and_set_terminal_color(unsigned level) {
     switch(level) {
         case LOG_LEVEL_DEBUG:
             set_terminal_fgcolor(LOG_DEBUG_COLOR);
@@ -22,24 +42,70 @@ const char* get_level_names_and_set_terminal_color(unsigned level) {
     }
 }
 
-void klog(int level, const char* string) {
-    kputs(get_level_names_and_set_terminal_color(level));
-    
+void klog(unsigned level, const char* string) {
+    if(level < current_level)
+        return; // avoid overflows
+
+    const char* level_name = get_level_names_and_set_terminal_color(level);
+
+
+// print on the screen
+// with fancy colors
+    kputs(level_name);
     set_terminal_fgcolor(TEXT_COLOR);
     
     kputs(string);
+    kputs("\n");
+
+// append to the buffer
+    append_string(level_name);
+    append_string(string);
+    append_string("\n");
 }
-void klogf(int level, const char* fmt, ...) {
-    va_list ap;
 
+
+void klogf(unsigned level, const char* fmt, ...) {
+    if(i > (BUFFER_SIZE * 3) / 4 || level < current_level)
+        return; // avoid overflows
+    
+    char string[1024];
+    
+// render string buffer 
+    va_list ap;
     va_start(ap, fmt);
+    vsprintf(string, fmt, ap);
+    va_end(ap);
 
 
-    kputs(get_level_names_and_set_terminal_color(level));
+    const char* level_name = get_level_names_and_set_terminal_color(level);
+
+// print on the screen
+// with fancy colors
+    kputs(level_name);
     
     set_terminal_fgcolor(TEXT_COLOR);
-    
-    vkprintf(fmt, ap);    
+    kputs(string);
+    kputs("\n");
+
+
+// append to the buffer
+    append_string(level_name);
+    append_string(string);
+    append_string("\n");
+}
+
+void set_logging_level(unsigned level) {
+    current_level = level;
+}
+
+
+const char* klog_get(void) {
+    buffer[i] = 0;
+    return buffer;
+}
+
+void klog_flush(void) {
+    i = 0;
+}
+
 
-    va_end(ap);
-}

kernel/debug/logging.h

@@ -15,21 +15,21 @@
 
 
 #ifndef NDEBUG
-#define log_debug(fmt, ...) klogf(LOG_LEVEL_DEBUG, fmt, __VA_ARGS__)
+#define klog_debug(fmt, ...) klogf(LOG_LEVEL_DEBUG, fmt, __VA_ARGS__)
 #else
-#define log_debug(fmt, ...)
+#define klog_debug(fmt, ...)
 #endif
 
-#define log_info(fmt, ...) \
-    if(NUMARGS(__VA_ARGS__) == 0) klog(LOG_LEVEL_DEBUG, fmt) \
-    else klogf(LOG_LEVEL_DEBUG, fmt, __VA_ARGS__)
+#define klog_info(...) klogf(LOG_LEVEL_INFO, __VA_ARGS__) 
+#define klog_warn(...) klogf(LOG_LEVEL_WARN, __VA_ARGS__)
 
-#define log_warn(fmt, ...) \
-    if(NUMARGS(__VA_ARGS__) == 0) klog(LOG_LEVEL_DEBUG, fmt) \
-    else klogf(LOG_LEVEL_DEBUG, fmt, __VA_ARGS__)
+void klog(unsigned level, const char* string);
 
+// behaves like kprintf
+void klogf(unsigned level, const char* fmt, ...);
 
-void klog(int level, const char* string);
+void set_logging_level(unsigned level);
 
-// behaves like kprintf
-void klogf(int level, const char* fmt, ...);
+const char* klog_get(void);
+
+void klog_flush(void);

kernel/entry.c

@@ -4,9 +4,9 @@
 
 #include "memory/gdt.h"
 #include "video/video.h"
+#include "video/terminal.h"
 #include "klib/sprintf.h"
 #include "klib/string.h"
-#include "video/terminal.h"
 #include "acpi/acpi.h"
 #include "common.h"
 #include "regs.h"
@@ -17,6 +17,7 @@
 #include "memory/physical_allocator.h"
 #include "memory/paging.h"
 #include "memory/vmap.h"
+#include "debug/logging.h"
  
 
 #define KERNEL_STACK_SIZE 8192
@@ -153,7 +154,8 @@ void _start(struct stivale2_struct *stivale2_struct) {
     }
         
  
-
+ // print all logging messages
+    set_logging_level(LOG_LEVEL_DEBUG);
 
     setup_isrs();
     read_acpi_tables((void*)rsdp_tag_ptr->rsdp);
@@ -172,14 +174,15 @@ void _start(struct stivale2_struct *stivale2_struct) {
     setup_terminal();
     append_paging_initialization();
 
-
-
     terminal_set_colors(0xfff0a0, 0x212121);
     terminal_clear();
     
         
     kputs(&_binary_bootmessage_txt);
-    kprintf("OUI\n");
+    
+    kprintf("boot logs:\n");
+    kputs(klog_get());
+    klog_flush();
 
     hpet_init();
     apic_setup_clock();

kernel/memory/physical_allocator.c

@@ -8,6 +8,7 @@
 #include "../debug/assert.h"
 #include "../debug/panic.h"
 #include "physical_allocator.h"
+#include "../debug/logging.h"
 #include "vmap.h"
 
 /**
@@ -180,7 +181,13 @@ void init_physical_allocator(const struct stivale2_struct_tag_memmap* memmap) {
     }
 
     n_ranges = j;
-    total_available_pages = total_pages - n_ranges; 
+    total_available_pages = total_pages - n_ranges;
+    klog_info(
+        "found %u MB of usable memory in the system (%u pages, %u physical ranges)",
+        total_available_pages * 4 / 1024,
+        total_available_pages,
+        n_ranges
+    );
 }