Make aarch64 compilable

Architecture/aarch64/Bootstrap/boot.S

@@ -0,0 +1,36 @@
+/* Based on this tutorial:
+   https://github.com/s-matyukevich/raspberry-pi-os */
+
+.section ".text.boot"
+
+.extern _bss_start
+.extern _bss_end
+
+.extern arm64Entry
+memzero:
+    str xzr, [x0], #8
+    subs x1, x1, #8
+    b.gt memzero
+    ret
+
+.global _start
+_start:
+    mrs x0, mpidr_el1
+    and x0, x0, #0xFF
+    cbz x0, _start2
+    b CPU_Loop
+
+_start2:
+    adr x0, _bss_start
+    adr x1, _bss_end
+    sub x1, x1, x0
+    bl memzero
+    mov sp, #0x200000
+    bl arm64Entry
+
+Halt:
+    wfe
+    b Halt
+
+CPU_Loop:
+    b CPU_Loop

Architecture/aarch64/cpu/SymmetricMultiprocessing.cpp

@@ -50,6 +50,8 @@ CPUData *GetCurrentCPU()
 
 namespace SMP
 {
+    int CPUCores = 0;
+
     void Initialize(void *madt)
     {
         fixme("SMP::Initialize() is not implemented!");

Architecture/aarch64/linker.ld

@@ -19,7 +19,15 @@ ENTRY(_start)
 
 SECTIONS
 {
-    . = 0x80000;
+    .text.boot :
+    {
+        *(.text.boot)
+        . += CONSTANT(MAXPAGESIZE);
+        _bss_start = .;
+        *(.text.bss)
+        _bss_end = .;
+    }
+
     _kernel_start = .;
     .text :
     {
@@ -43,6 +51,22 @@ SECTIONS
     . = ALIGN(4096);
     _kernel_rodata_end = .;
 
+    .init_array :
+    {
+        PROVIDE_HIDDEN(__init_array_start = .);
+        KEEP(*(.init_array .ctors))
+        KEEP(*(SORT_BY_INIT_PRIORITY(.init_array.*) SORT_BY_INIT_PRIORITY(.ctors.*)))
+        PROVIDE_HIDDEN (__init_array_end = .);
+    }
+
+    .fini_array :
+    {
+        PROVIDE_HIDDEN(__fini_array_start = .);
+        KEEP(*(SORT_BY_INIT_PRIORITY(.fini_array.*) SORT_BY_INIT_PRIORITY(.dtors.*)))
+        KEEP(*(.fini_array .dtors))
+        PROVIDE_HIDDEN (__fini_array_end = .);
+    }
+
     .bss :
     {
         *(.bss .bss.*)

Architecture/aarch64/runtime/crt1.S

@@ -1,17 +1,17 @@
-.section ".text.boot"
+// .section ".text.boot"
 
-.global _start
+// .global _start
-    .org 0x80000
+//     .org 0x80000
-_start:
+// _start:
-    ldr     x5, =_start
+//     ldr     x5, =_start
-    mov     sp, x5
+//     mov     sp, x5
-    ldr     x5, =_kernel_rodata_end
+//     ldr     x5, =_kernel_rodata_end
-    ldr     w6, =_bss_size
+//     ldr     w6, =_bss_size
-1:  cbz     w6, 2f
+// 1:  cbz     w6, 2f
-    str     xzr, [x5], #8
+//     str     xzr, [x5], #8
-    sub     w6, w6, #1
+//     sub     w6, w6, #1
-    cbnz    w6, 1b
+//     cbnz    w6, 1b
-2:  bl      arm64Entry
+// 2:  bl      arm64Entry
-Halt:
+// Halt:
-    wfe
+//     wfe
-    b Halt
+//     b Halt

Architecture/aarch64/runtime/crti.S

@@ -1,13 +1,13 @@
-.section .init
+// .section .init
-.global _init
+// .global _init
-.type _init, @function
+// .type _init, @function
-_init:
+// _init:
 //	push %rbp
 //	movq %rsp, %rbp
 
-.section .fini
+// .section .fini
-.global _fini
+// .global _fini
-.type _fini, @function
+// .type _fini, @function
-_fini:
+// _fini:
 //	push %rbp
 //	movq %rsp, %rbp

Makefile

@@ -66,8 +66,8 @@ SIMD_FLAGS := -msse -msse2 -msse3 -mssse3 -msse4.1 -msse4.2 -mavx -mavx2 -mavx51
 
 ifeq ($(OSARCH), amd64)
 
-CFLAGS += -fno-pic -fno-pie							\
+CFLAGS += -fno-pic -fno-pie					\
-		  -mno-red-zone -march=core2 -pipe			\
+		  -mno-red-zone -march=core2 -pipe	\
 		  -mcmodel=kernel -fno-builtin -Da64
 CFLAG_STACK_PROTECTOR := -fstack-protector-all
 LDFLAGS += -TArchitecture/amd64/linker.ld 	\
@@ -92,9 +92,13 @@ LDFLAGS += -TArchitecture/i386/linker.ld 	\
 
 else ifeq ($(OSARCH), aarch64)
 
-CFLAGS += -pipe -fno-builtin -fPIC -Wstack-protector -Daa64
+CFLAGS += -pipe -fno-builtin -Wstack-protector -Daa64 -fPIC -mno-outline-atomics
-CFLAG_STACK_PROTECTOR := -fstack-protector-all -fstack-clash-protection
+CFLAG_STACK_PROTECTOR := -fstack-protector-all
-LDFLAGS += -TArchitecture/aarch64/linker.ld -fPIC
+LDFLAGS += -TArchitecture/aarch64/linker.ld -fPIC -pie \
+	-Wl,-static,--no-dynamic-linker,-ztext \
+	-nostdlib -nodefaultlibs -nolibc \
+	-zmax-page-size=0x1000 \
+	-Wl,-Map kernel.map -static
 
 endif
 
@@ -166,13 +170,7 @@ endif
 
 %.o: %.S
 	$(info Compiling $<)
-ifeq ($(OSARCH), amd64)
 	$(AS) -c $< -o $@
-else ifeq ($(OSARCH), i386)
-	$(AS) -c $< -o $@
-else ifeq ($(OSARCH), aarch64)
-	$(AS) -c $< -o $@
-endif
 
 %.o: %.psf
 ifeq ($(OSARCH), amd64)