Kernel: Don't load AP init code to 0xF000, but relocate it later

This cleans up the kernel executable as bootloaders don't have to
load AP init code straight to 0xF000, but it will be moved there once
kernel is doing the AP initialization.

kernel/arch/i686/Signal.S

@@ -1,4 +1,4 @@
-.section .userspace, "aw"
+.section .userspace, "ax"
 
 // stack contains
 //    return address

kernel/arch/i686/boot.S

@@ -235,26 +235,31 @@ system_halt:
 	jmp 1b
 
 
+#define AP_V2P(vaddr) ((vaddr) - ap_trampoline + 0xF000)
+
 .section .ap_init, "ax"
 
 .code16
 .global ap_trampoline
 ap_trampoline:
 	jmp 1f
+
 .align 8
 ap_stack_ptr:
 	.skip 4
-1:
-	cli; cld
-	ljmpl $0x00, $ap_cs_clear
-ap_cs_clear:
+ap_stack_loaded:
+	.skip 1
 
+1:	cli; cld
+	ljmpl $0x00, $AP_V2P(ap_cs_clear)
+
+ap_cs_clear:
 	# load ap gdt and enter protected mode
-	lgdt ap_gdtr
+	lgdt AP_V2P(ap_gdtr)
 	movl %cr0, %eax
 	orb $1, %al
 	movl %eax, %cr0
-	ljmpl $0x08, $ap_protected_mode
+	ljmpl $0x08, $AP_V2P(ap_protected_mode)
 
 .code32
 ap_protected_mode:
@@ -263,16 +268,15 @@ ap_protected_mode:
 	movw %ax, %ss
 	movw %ax, %es
 
-	movl ap_stack_ptr, %esp
-	movb $1, V2P(g_ap_stack_loaded)
+	movl AP_V2P(ap_stack_ptr), %esp
+	movb $1, AP_V2P(ap_stack_loaded)
 
-	call V2P(enable_sse)
-
-	call V2P(initialize_paging)
+	leal V2P(enable_sse),        %ecx; call *%ecx
+	leal V2P(initialize_paging), %ecx; call *%ecx
 
 	# load boot gdt and enter long mode
 	lgdt V2P(boot_gdtr)
-	ljmpl $0x08, $ap_flush_gdt
+	ljmpl $0x08, $AP_V2P(ap_flush_gdt)
 
 ap_flush_gdt:
 	# move stack pointer to higher half

kernel/arch/i686/linker.ld

@@ -4,13 +4,6 @@ KERNEL_OFFSET = 0xC0000000;
 
 SECTIONS
 {
-	. = 0xF000;
-	.ap_init ALIGN(4K) : AT(ADDR(.ap_init))
-	{
-		g_ap_init_addr = .;
-		*(.ap_init)
-	}
-
 	. = 0x00100000 + KERNEL_OFFSET;
 
 	g_kernel_start = .;
@@ -28,15 +21,20 @@ SECTIONS
 		g_userspace_end = .;
 		g_kernel_execute_end = .;
 	}
-	.rodata ALIGN(4K) : AT(ADDR(.rodata) - KERNEL_OFFSET)
+	.ap_init ALIGN(4K) : AT(ADDR(.ap_init))
 	{
-		*(.rodata.*)
+		g_ap_init_addr = .;
+		*(.ap_init)
 	}
 	.data ALIGN(4K) : AT(ADDR(.data) - KERNEL_OFFSET)
 	{
 		g_kernel_writable_start = .;
 		*(.data)
 	}
+	.rodata ALIGN(4K) : AT(ADDR(.rodata) - KERNEL_OFFSET)
+	{
+		*(.rodata.*)
+	}
 	.bss ALIGN(4K) : AT(ADDR(.bss) - KERNEL_OFFSET)
 	{
 		*(COMMON)