feat(ke): integrate the logger with KConfig

Kconfig

@@ -57,4 +57,9 @@ config NCPUS
 	   help
 			This option sets the maximum number of CPUs the kernel can support.
 
+config LOG_BUFFER_SHIFT
+         int "Log buffer size shift"
+         default 14
+         help
+             This option sets the size of the kernel log buffer as a power of two. The actual size is calculated as 2 raised to the power of this value (i.e., 2^LOG_BUFFER_SHIFT bytes).
 endmenu

src/kern/log.zig

@@ -4,6 +4,7 @@ const rtl = @import("rtl");
 const pl = b.pl;
 const ke = b.ke;
 const ki = ke.private;
+const config = @import("config");
 
 const DebugWriter = struct {
     interface: std.Io.Writer,
@@ -31,7 +32,10 @@ const DebugWriter = struct {
     }
 };
 
-var ringbuffer = ki.log_ring.RingBuffer(14, 5).init();
+// Messages are on average 2^5 = 32 bytes.
+const avg_msg_size_bits = 5;
+
+var ringbuffer = ki.log_ring.RingBuffer(config.CONFIG_LOG_BUFFER_SHIFT, avg_msg_size_bits).init();
 
 pub fn log(
     comptime level: std.log.Level,