Cleaning up and adding page fault handler

[tpg/acess2.git] / Kernel / arch / x86_64 / start64.asm

diff --git a/Kernel/arch/x86_64/start64.asm b/Kernel/arch/x86_64/start64.asm
index bf7293b..04bac26 100644 (file)
--- a/Kernel/arch/x86_64/start64.asm
+++ b/Kernel/arch/x86_64/start64.asm
@@ -2,14 +2,131 @@
 ; Acess2 x86_64 Port
 ;
 [bits 64]
+KERNEL_BASE    equ     0xFFFF800000000000
 
+[extern kmain]
+
+[extern gMultibootPtr]
+[extern gMultibootMagic]
+
+[section .text]
 [global start64]
 start64:
+       ; 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
-       jmp $
+       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:
+       str ax
+       mov gs, ax
+       xor rax, rax
+       mov al, [gs:104]        ; End of TSS
+       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:
+