X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86_64%2Fstart64.asm;h=5027a1e8ba302a27b8401277ccc478919decfa32;hb=a59083b859599aeee6ab3e4fd6a0113faa5fddf5;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..5027a1e8 100644
--- a/Kernel/arch/x86_64/start64.asm
+++ b/Kernel/arch/x86_64/start64.asm
@@ -2,6 +2,162 @@
 ; Acess2 x86_64 Port
 ;
 [bits 64]
+;KERNEL_BASE	equ	0xFFFF800000000000
+KERNEL_BASE	equ	0xFFFFFFFF80000000
 
+[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:
+	
+	xor rax, rax
+	mov dr0, rax	; Set CPU0
+	
+	; 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, 0xFFFFA00000000000 + 0x10000
+	
+	; Call main
+	mov edi, [gMultibootMagic - KERNEL_BASE]
+	mov esi, [gMultibootPtr - KERNEL_BASE]
+	call kmain
+	
+	cli
+.hlt:
+	hlt
+	jmp .hlt
+
+[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
+	push r10
+	push r11
+	
+	mov [rbp+2*8], rdi	; Save Ptr to stack
+	
+	mov r11, rsi	; NArgs
+	mov r10, rdx	; Args
+
+	; Arg 1: RDI
+	mov rdi, [r10]
+	add r10, 8
+	dec r11
+	jz .call
+	; Arg 2: RSI
+	mov rsi, [r10]
+	add r10, 8
+	dec r11
+	jz .call
+	; Arg 3: RDX
+	mov rdx, [r10]
+	add r10, 8
+	dec r11
+	jz .call
+	; Arg 4: RCX
+	mov rcx, [r10]
+	add r10, 8
+	dec r11
+	jz .call
+	; Arg 5: R8
+	mov r8, [r10]
+	add r10, 8
+	dec r11
+	jz .call
+	; Arg 6: R9
+	mov r9, [r10]
+	add r10, 8
+	dec r11
+	jz .call
+	; No support for more
+
+.call:
+	mov rax, [rbp+2*8]	; Ptr
+	call rax
+	
+	pop r11
+	pop r10
+	
+	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
+