wip swift in kernel

Kernel/CMakeLists.txt

@@ -1,6 +1,10 @@
 cmake_minimum_required(VERSION 3.10)
 project(ksOSKernel LANGUAGES ASM C)
 
+set(SWIFT_TOOLCHAIN "$ENV{HOME}/Library/Developer/Toolchains/swift-6.2.3-RELEASE.xctoolchain")
+set(SWIFTC "${SWIFT_TOOLCHAIN}/usr/bin/swiftc")
+set(SWIFT_RESOURCE_DIR "${SWIFT_TOOLCHAIN}/usr/lib/swift")
+
 add_compile_options(-ffreestanding -nostdlib -O0 -g)
 
 set(LINKER_SCRIPT ${CMAKE_CURRENT_SOURCE_DIR}/linker.ld)
@@ -11,8 +15,33 @@ add_link_options(
     -Wl,-T,${LINKER_SCRIPT}
 )
 
-add_executable(kernel.elf Source/entry.S)
+set(SWIFT_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/Source/kernel.swift)
+set(SWIFT_OBJ ${CMAKE_CURRENT_BINARY_DIR}/kernel_swift.o)
+
+add_custom_command(
+    OUTPUT ${SWIFT_OBJ}
+    COMMAND ${SWIFTC}
+        -target aarch64-none-none-elf
+        -enable-experimental-feature Embedded
+        -parse-as-library
+        -wmo
+        -O
+        -Xcc -fno-stack-protector
+        -resource-dir ${SWIFT_RESOURCE_DIR}
+        -c ${SWIFT_SOURCES}
+        -o ${SWIFT_OBJ}
+    DEPENDS ${SWIFT_SOURCES}
+    COMMENT "Compiling Swift kernel"
+)
+
+set_source_files_properties(${SWIFT_OBJ} PROPERTIES
+    EXTERNAL_OBJECT TRUE
+    GENERATED TRUE
+)
+
+add_executable(kernel.elf Source/entry.S Source/stubs.c ${SWIFT_OBJ})
+
 add_custom_command(TARGET kernel.elf POST_BUILD
     COMMAND ${LLVM_OBJCOPY} -O binary kernel.elf kernel.bin
     COMMENT "kernel.elf -> kernel.bin"
-)
+)

Kernel/Source/entry.S

@@ -2,59 +2,6 @@
 .global _start
 
 _start:
-    add x1, x0, #64
+    bl kmain
-    ldr x2, [x1]            // base
+.hang:
-    ldr x3, [x1, #16]       // width
+    b .hang
-    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

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; }

Kernel/linker.ld

@@ -0,0 +1,14 @@
+ENTRY(_start)
+
+SECTIONS {
+    . = 0;
+
+    .text : {
+        *(.text.boot)
+        *(.text*)
+    }
+
+    .rodata : { *(.rodata*) }
+    .data   : { *(.data*)   }
+    .bss    : { *(.bss*) *(COMMON) }
+}