Improve exemple kernel.

.gitignore

@@ -1 +1,4 @@
 .vscode/
+*.o
+*.d
+*.elf

exemple/kmain.c

@@ -1,12 +1,132 @@
 #define HANDOVER_INCLUDE_MACROS
-#define HANDOVER_INCLUDE_HEADER
+#define HANDOVER_INCLUDE_UTILITES
 
-#include "handover.h"
-
-void ho_printf(void *ctx, char const *format, ...);
+#include <stdarg.h>
+#include "../handover.h"
 
 HANDOVER(WITH_FB, WITH_FILES);
 
+// simple printf implementation that supports %s %d %x %p
+
+size_t cstrlen(const char *str)
+{
+    size_t len = 0;
+    while (str[len])
+        len++;
+    return len;
+}
+
+void putc(char c)
+{
+    asm volatile("outb %0, %1"
+                 :
+                 : "a"(c), "Nd"(0xe9));
+}
+
+void cstrrev(char s[])
+{
+    for (int i = 0, j = cstrlen(s) - 1; i < j; i++, j--)
+    {
+        char c = s[i];
+        s[i] = s[j];
+        s[j] = c;
+    }
+}
+
+void itoa(int n, char s[], int base)
+{
+    int i, sign;
+
+    if ((sign = n) < 0)
+        n = -n;
+    i = 0;
+    do
+    {
+        s[i++] = n % base + '0';
+    } while ((n /= base) > 0);
+
+    if (sign < 0)
+        s[i++] = '-';
+
+    s[i] = '\0';
+    cstrrev(s);
+}
+
+void puts(const char *s)
+{
+    while (*s)
+    {
+        putc(*s);
+        s++;
+    }
+}
+
+void printf(const char *fmt, ...)
+{
+    va_list va;
+    va_start(va, fmt);
+
+    while (*fmt)
+    {
+        if (*fmt == '%')
+        {
+            fmt++;
+
+            if (*fmt == 's')
+            {
+                puts(va_arg(va, const char *));
+            }
+            else if (*fmt == 'd')
+            {
+                int number = va_arg(va, int);
+                if (number < 0)
+                {
+                    putc('-');
+                    number = -number;
+                }
+                char buffer[sizeof(int) * 8 + 1];
+                itoa(number, buffer, 10);
+                puts(buffer);
+            }
+            else if (*fmt == 'x')
+            {
+                int number = va_arg(va, int);
+                char buffer[sizeof(size_t) * 8 + 1];
+                itoa(number, buffer, 16);
+                puts(buffer);
+            }
+            else if (*fmt == '%')
+            {
+                putc('%');
+            }
+        }
+        else
+        {
+            putc(*fmt);
+        }
+
+        fmt++;
+    }
+
+    va_end(va);
+}
+
 void _kmain(uint64_t magic, HandoverPayload *payload)
 {
+    printf("Handover magic: %x", magic);
+    printf("Handover payload: %x", payload);
+
+    printf("Handover agent: %s", payload->agent);
+    printf("Handover size: %d", payload->size);
+    printf("Handover count: %d", payload->count);
+
+    for (size_t i = 0; i < payload->count; i++)
+    {
+        HandoverRecord record = payload->records[i];
+        printf("Handover tag: %s(%x)", handover_tag_name(record.tag), record.tag);
+        printf("    flags: %x", record.flags);
+        printf("    start: %d", record.start);
+        printf("    size: %d", record.size);
+        printf("    more: %x", record.more);
+    }
 }

exemple/makefile

@@ -51,7 +51,7 @@ override INTERNALLDFLAGS :=     \
     -Wl,-T,linker.ld
 
 # Use find to glob all *.c files in the directory and extract the object names.
-override CFILES := $(shell find ./ -type f -name '*.c')
+override CFILES := $(shell find ./ -type f -name '*.c') ../handover.c
 override OBJ := $(CFILES:.c=.o)
 override HEADER_DEPS := $(CFILES:.c=.d)
 

handover.c

@@ -50,31 +50,31 @@ HandoverRecord handover_half_under(HandoverRecord self, HandoverRecord other)
     if (handover_overlap(self, other) &&
         self.start < other.start)
     {
-        return {
+        return (HandoverRecord){
             .tag = self.tag,
             .flags = 0,
             .start = self.start,
             .size = other.start - self.start,
         };
     }
 
-    return {};
+    return (HandoverRecord){};
 }
 
 HandoverRecord handover_half_over(HandoverRecord self, HandoverRecord other)
 {
     if (handover_overlap(self, other) &&
         self.start + self.size > other.start + other.size)
     {
-        return {
+        return (HandoverRecord){
             .tag = self.tag,
             .flags = 0,
             .start = other.start + other.size,
             .size = self.start + self.size - other.start - other.size,
         };
     }
 
-    return {};
+    return (HandoverRecord){};
 }
 
 void handover_insert(HandoverPayload *payload, size_t index, HandoverRecord record)
@@ -156,3 +156,8 @@ void handover_append(HandoverPayload *payload, HandoverRecord record)
 
     payload->records[payload->count++] = record;
 }
+
+char const *handover_str(HandoverPayload const *payload, uint32_t offset)
+{
+    return (char const *)payload + offset;
+}

handover.h

@@ -1,6 +1,7 @@
 #ifndef HANDOVER_H_INCLUDED
 #define HANDOVER_H_INCLUDED
 
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ -131,7 +132,7 @@ typedef void HandoverEntry(
 
 #ifdef HANDOVER_INCLUDE_UTILITES
 
-char const *handover_tag_name(HandoverTag tag);
+char const *handover_tag_name(uint32_t tag);
 
 bool handover_mergeable(uint32_t tag);
 
@@ -151,6 +152,8 @@ void handover_remove(HandoverPayload *payload, size_t index);
 
 void handover_append(HandoverPayload *payload, HandoverRecord record);
 
+char const *handover_str(HandoverPayload const *payload, uint32_t offset);
+
 #endif
 
 #endif