feat: add printk and vprintk functions with Linux-style log level parsing

2 files changed, 70 insertions, 0 deletions

diff --git a/na/include/lume/klog.h b/na/include/lume/klog.h
index 457dcfe..b63810f 100644
--- a/na/include/lume/klog.h
+++ b/na/include/lume/klog.h
@@ -108,6 +108,11 @@ void klog(KlogLevel level, const char* fmt, ...);
 __attribute__((format(printf, 3, 4)))
 void klog_ex(KlogLevel level, KlogSubsys subsys, const char* fmt, ...);
 
+/* Linux-style printk interface */
+__attribute__((format(printf, 1, 2)))
+int printk(const char* fmt, ...);
+int vprintk(const char* fmt, __builtin_va_list va);
+
 /* Set runtime log level filter. Messages above this level are
  * still stored in the ring buffer but not printed to console. */
 void klog_set_level(KlogLevel level);
@@ -160,6 +165,21 @@ void klog_stats(KlogStats* out);
 #define pr_debug(fmt, ...)  do {} while (0)
 #endif
 
+/* Linux kernel loglevel prefixes */
+#define KERN_SOH    "\001"
+#define KERN_EMERG  KERN_SOH "0"
+#define KERN_ALERT  KERN_SOH "1"
+#define KERN_CRIT   KERN_SOH "2"
+#define KERN_ERR    KERN_SOH "3"
+#define KERN_WARNING KERN_SOH "4"
+#define KERN_NOTICE KERN_SOH "5"
+#define KERN_INFO   KERN_SOH "6"
+#define KERN_DEBUG  KERN_SOH "7"
+
+/* Boot stage log (thin wrapper over printk) */
+#define BOOT_STAGE(n, desc) \
+    printk(KERN_INFO "STAGE%u %s\n", (unsigned)(n), (desc))
+
 extern "C" [[noreturn]] void kernel_panic(const char* msg, const char* detail = nullptr);
 
 #ifdef __cplusplus
diff --git a/na/lib/klog.cc b/na/lib/klog.cc
index c67971b..bf081de 100644
--- a/na/lib/klog.cc
+++ b/na/lib/klog.cc
@@ -86,6 +86,27 @@ static const char* klog_subsys_name(KlogSubsys subsys)
     return "?";
 }
 
+static const char* parse_kern_level(const char* fmt, KlogLevel* level)
+{
+    if (!fmt || !level) {
+        return fmt;
+    }
+
+    /* Linux-style "\001n" prefix (KERN_SOH) */
+    if (fmt[0] == '\001' && fmt[1] >= '0' && fmt[1] <= '7') {
+        *level = static_cast<KlogLevel>(fmt[1] - '0');
+        return fmt + 2;
+    }
+
+    /* Alternate "<n>" prefix */
+    if (fmt[0] == '<' && fmt[1] >= '0' && fmt[1] <= '7' && fmt[2] == '>') {
+        *level = static_cast<KlogLevel>(fmt[1] - '0');
+        return fmt + 3;
+    }
+
+    return fmt;
+}
+
 /* ========================================================================
  * Ring Buffer Operations
  * ======================================================================== */
@@ -320,6 +341,35 @@ static void klog_vex(KlogLevel level, KlogSubsys subsys,
     }
 }
 
+int vprintk(const char* fmt, __builtin_va_list va)
+{
+    KlogLevel level = KLOG_INFO;
+    const char* real_fmt = parse_kern_level(fmt, &level);
+
+    __builtin_va_list va_copy;
+    __builtin_va_copy(va_copy, va);
+
+    char tmp[KLOG_LINE_MAX + 1];
+    int len = vsnprintf_(tmp, KLOG_LINE_MAX, real_fmt, va_copy);
+    __builtin_va_end(va_copy);
+
+    klog_vex(level, KLOG_SUBSYS_GENERIC, real_fmt, va);
+
+    if (len < 0) {
+        return 0;
+    }
+    return len;
+}
+
+int printk(const char* fmt, ...)
+{
+    __builtin_va_list va;
+    __builtin_va_start(va, fmt);
+    int ret = vprintk(fmt, va);
+    __builtin_va_end(va);
+    return ret;
+}
+
 void klog_set_level(KlogLevel level)
 {
     g_klog.console_level = level;