wip swift in kernel

Kernel/Source/entry.S

@@ -2,59 +2,6 @@
 .global _start
 
 _start:
-    add x1, x0, #64
-    ldr x2, [x1]            // base
-    ldr x3, [x1, #16]       // width
-    ldr x4, [x1, #24]       // height
-    
-    mul x5, x3, x4 
-    mov x7, #5
-    udiv x10, x5, x7        // stripe size
-
-    // 0x00RRGGBB
-    // lblue: 5B CE FA
-    mov w11, #0xCEFA
-    movk w11, #0x5B, lsl #16
-    
-    // pink: F5 A7 B8
-    mov w12, #0xA7B8
-    movk w12, #0xF5, lsl #16
-    
-    // white: FF FF FF
-    mov w13, #0xFFFF
-    movk w13, #0xFF, lsl #16
-
-    mov x14, #0             // pixels in curr stripe
-    mov x15, #0             // stripe index
-
-fill_loop:
-    cbz x5, done
-
-    cmp x15, #0
-    b.eq set_blue
-    cmp x15, #1
-    b.eq set_pink
-    cmp x15, #2
-    b.eq set_white
-    cmp x15, #3
-    b.eq set_pink
-    b set_blue
-
-set_blue:  mov w6, w11; b draw
-set_pink:  mov w6, w12; b draw
-set_white: mov w6, w13
-
-draw:
-    str w6, [x2], #4
-    sub x5, x5, #1
-    add x14, x14, #1
-
-    cmp x14, x10
-    b.lt fill_loop
-    
-    mov x14, #0
-    add x15, x15, #1
-    b fill_loop
-
-done:
-    b done
+    bl kmain
+.hang:
+    b .hang

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
+    }
+}

Kernel/Source/stubs.c

@@ -0,0 +1,38 @@
+#include <stddef.h>
+
+void* memmove(void* dest, const void* src, unsigned long n) {
+    unsigned char* d = (unsigned char*)dest;
+    const unsigned char* s = (const unsigned char*)src;
+    if (d < s) {
+        while (n--) *d++ = *s++;
+    } else {
+        d += n; s += n;
+        while (n--) *--d = *--s;
+    }
+    return dest;
+}
+
+void* memcpy(void* dest, const void* src, unsigned long n) {
+    return memmove(dest, src, n);
+}
+
+void* memset(void* dest, int c, unsigned long n) {
+    unsigned char* d = (unsigned char*)dest;
+    while (n--) *d++ = (unsigned char)c;
+    return dest;
+}
+
+// Stack protection
+long __stack_chk_guard = (long)0xDEADBEEFCAFEBABEULL;
+void __stack_chk_fail(void) { while (1); }
+
+// Swift embedded uses putchar for print(); stub so it links but does nothing
+int putchar(int c) { return c; }
+
+// Swift runtime allocator stubs — should never be called in embedded mode
+int posix_memalign(void** ptr, unsigned long align, unsigned long size) {
+    (void)ptr; (void)align; (void)size;
+    while (1);
+}
+
+void free(void* ptr) { (void)ptr; }