wip swift in kernel

Kernel/Source/kernel.swift

@@ -0,0 +1,22 @@
+@_cdecl("kmain")
+public func kernelMain(_ bootInfo: UInt) {
+    // Bootinfo offsets: fb starts at 64, then base(8), baseSize(8), width(8), height(8)
+    let fbBase = UnsafePointer<UInt>(bitPattern: bootInfo &+ 64)!.pointee
+    let width  = UnsafePointer<UInt64>(bitPattern: bootInfo &+ 80)!.pointee
+    let height = UnsafePointer<UInt64>(bitPattern: bootInfo &+ 88)!.pointee
+
+    let pixels = UnsafeMutablePointer<UInt32>(bitPattern: fbBase)!
+    let total  = Int(width) &* Int(height)
+    let stripe = total / 5
+
+    var i = 0
+    while i < total {
+        let s = i / stripe
+        let color: UInt32
+        if s == 0 || s >= 4 { color = 0x5BCEFA }
+        else if s == 2      { color = 0xFFFFFF  }
+        else                 { color = 0xF5A7B8  }
+        pixels[i] = color
+        i &+= 1
+    }
+}