stdio kprintf working

kern/libkern/stdio.c

@@ -0,0 +1,20 @@
+#include <uart.h>
+#include <mini-printf.h>
+#include <stddef.h>
+
+int stdout_puts(char *s, int len, void *unused) {
+    (void)unused;
+    // Example: UART write loop
+    for (int i = 0; i < len; i++) {
+        uart_putc(s[i]);   // <-- your low-level "put char" routine
+    }
+    return len;
+}
+
+int kprintf(const char *restrict fmt, ...) {
+    va_list ap;
+    va_start(ap, fmt);
+    int ret = mini_vpprintf(stdout_puts, NULL, fmt, ap);
+    va_end(ap);
+    return ret;
+}

kern/libkern/stdio.h

@@ -0,0 +1,18 @@
+#ifndef STDIO_H
+#define STDIO_H
+
+int stdout_puts(char *s, int len, void *unused);
+int kprintf(const char *restrict format, ...);
+
+// int fprintf(FILE *restrict stream, const char *restrict format, ...);
+// int dprintf(int fd, const char *restrict format, ...);
+// int sprintf(char *restrict str, const char *restrict format, ...);
+// int snprintf(char str[restrict.size], size_t size, const char *restrict format, ...);
+
+// int vprintf(const char *restrict format, va_list ap);
+// int vfprintf(FILE *restrict stream, const char *restrict format, va_list ap);
+// int vdprintf(int fd, const char *restrict format, va_list ap);
+// int vsprintf(char *restrict str, const char *restrict format, va_list ap);
+// int vsnprintf(char str[restrict.size], size_t size, const char *restrict format, va_list ap);
+
+#endif // STDIO_H