X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86%2Fstart.asm;h=f1d1ea7467ab15ad1b8c75101a3bc0b5ee197b82;hb=ca05044548d5c1de87c030d625a305731a6cc665;hp=41351600054e84eb198b94487dd4b781b14570de;hpb=6749674b892a0865abc22f9a6ec9a624ff40a283;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86/start.asm b/Kernel/arch/x86/start.asm
index 41351600..f1d1ea74 100644
--- a/Kernel/arch/x86/start.asm
+++ b/Kernel/arch/x86/start.asm
@@ -39,8 +39,6 @@ start:
 	jmp ecx
 .higherHalf:
 
-	mov DWORD [gaInitPageDir], 0
-
 	; Call the kernel
 	push ebx	; Multiboot Info
 	push eax	; Multiboot Magic Value
@@ -52,6 +50,65 @@ start:
 	hlt
 	jmp .hlt
 
+; 
+; Multiprocessing AP Startup Code (Must be within 0x10FFF0)
+;
+%if USE_MP
+[extern gGDT]
+[extern gGDTPtr]
+[extern gIDTPtr]
+[extern gpMP_LocalAPIC]
+[extern gaAPIC_to_CPU]
+[extern gaCPUs]
+[extern giNumInitingCPUs]
+lGDTPtr:	; Local GDT Pointer
+	dw	2*8-1
+	dd	gGDT-KERNEL_BASE
+
+[bits 16]
+[global APStartup]
+APStartup:
+	xchg bx, bx	; MAGIC BREAK!
+	mov ax, 0xFFFF
+	mov ds, ax
+	lgdt [DWORD ds:lGDTPtr-KERNEL_BASE-0xFFFF0]
+	mov eax, cr0
+	or	al, 1
+	mov	cr0, eax
+	jmp 08h:DWORD .ProtectedMode-KERNEL_BASE
+[bits 32]
+.ProtectedMode:
+	; Start Paging
+	mov eax, gaInitPageDir - KERNEL_BASE
+	mov cr3, eax
+	mov eax, cr0
+	or	eax, 0x80010000	; PG and WP
+	mov cr0, eax
+	; Jump to higher half
+	lea eax, [.higherHalf]
+	jmp eax
+.higherHalf:
+	; Load True GDT & IDT
+	lgdt [gGDTPtr]
+	lidt [gIDTPtr]
+
+	mov eax, [gpMP_LocalAPIC]
+	mov DWORD [eax], 0
+	xor ecx, ecx
+	mov cl, BYTE [eax+0x10]
+	; CL is now local APIC ID
+	mov cl, BYTE [gaAPIC_to_CPU+ecx]
+	; CL is now the CPU ID
+	mov BYTE [gaCPUs+ecx*8+1], 1
+	; Decrement the remaining CPU count
+	dec DWORD [giNumInitingCPUs]
+	; CPU is now marked as initialised
+	sti
+.hlt:
+	hlt
+	jmp .hlt
+%endif
+
 [global GetEIP]
 GetEIP:
 	mov eax, [esp]