X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86_64%2Fstart64.asm;h=33c77d6277330dd39eac664662595542802c6c27;hb=e6d539f85a06fb3d25b985d1a27d8648d23736f0;hp=67ba23c9532eb62ac25bec34965234c296f17255;hpb=43f12a083f112a410859597c5f45e78b1de2e7c8;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86_64/start64.asm b/Kernel/arch/x86_64/start64.asm
index 67ba23c9..33c77d62 100644
--- a/Kernel/arch/x86_64/start64.asm
+++ b/Kernel/arch/x86_64/start64.asm
@@ -2,6 +2,131 @@
 ; Acess2 x86_64 Port
 ;
 [bits 64]
+KERNEL_BASE	equ	0xFFFF800000000000
 
+[extern kmain]
+
+[extern gMultibootPtr]
+[extern gMultibootMagic]
+
+[section .text]
+[global start64]
 start64:
-	jmp $
+	; Load Registers
+	mov ax, 0x10
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	
+	; Go to high memory
+	mov rax, start64.himem
+	jmp rax
+.himem:
+	
+	; Clear the screen
+	mov rax, 0x1F201F201F201F20	; Set the screen to White on blue, space (4 characters)
+	mov edi, 0xB8000
+	mov ecx, 80*25*2/8
+	rep stosq
+	
+	; Set kernel stack
+	mov rsp, gInitialKernelStack
+	
+	; Call main
+	mov edi, [gMultibootMagic - KERNEL_BASE]
+	mov esi, [gMultibootPtr - KERNEL_BASE]
+	call kmain
+	
+	cli
+.hlt:
+	hlt
+	jmp .hlt
+
+[global GetRIP]
+GetRIP:
+	mov rax, [rsp]
+	ret
+
+[global GetCPUNum]
+GetCPUNum:
+	xor rax, rax
+	str ax
+	sub ax, 0x38	; TSS Base
+	shr ax, 4	; One 16-byte TSS per CPU
+	ret
+
+KSTACK_USERSTATE_SIZE	equ	(16+1+5)*8	; GPRegs, CPU, IRET
+[global Proc_ReturnToUser]
+[extern Proc_GetCurThread]
+Proc_ReturnToUser:
+	; RBP is the handler to use
+	
+	call Proc_GetCurThread
+	
+	; EAX is the current thread
+	mov rbx, rax
+	mov rax, [rbx+40]	; Get Kernel Stack
+	sub rax, KSTACK_USERSTATE_SIZE
+	
+	;
+	; NOTE: This can cause corruption if the signal happens while the user
+	;       has called a kernel operation.
+	; Good thing this can only be called on a user fault.
+	;
+	
+	; Get and alter User SP
+	mov rcx, [rax+KSTACK_USERSTATE_SIZE-3*8]
+	mov rdx, [rbx+60]	; Get Signal Number
+	mov [rcx-8], rdx
+	mov rax, User_Syscall_RetAndExit
+	mov [rcx-16], rax
+	sub rcx, 16
+	
+	; Restore Segment Registers
+	mov ax, 0x23
+	mov ds, ax
+	mov es, ax
+	
+	push 0x23	; SS
+	push rcx	; RSP
+	push 0x202	; RFLAGS (IF and Rsvd)
+	push 0x1B	; CS
+	push rbp	; RIP
+	
+	iret
+
+; int CallWithArgArray(void *Ptr, int NArgs, Uint *Args)
+; Call a function passing the array as arguments
+[global CallWithArgArray]
+CallWithArgArray:
+	push rbp
+	mov rbp, rsp
+	mov rcx, [rbp+3*8]	; Get NArgs
+	mov rdx, [rbp+4*8]
+
+.top:
+	mov rax, [rdx+rcx*8-8]
+	push rax
+	loop .top
+	
+	mov rax, [rbp+2*8]
+	call rax
+	lea rsp, [rbp]
+	pop rbp
+	ret
+
+[section .usertext]
+User_Syscall_RetAndExit:
+	mov rdi, rax
+	jmp User_Syscall_Exit
+User_Syscall_Exit:
+	xor rax, rax
+	; RDI: Return Value
+	int 0xAC
+
+[section .bss]
+[global gInitialKernelStack]
+	resd	1024*4	; 4 Pages
+gInitialKernelStack:
+