Kernel/x86 - Cleaning up dead code

[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 a2ffb19..b63b63a 100644 (file)
--- a/Kernel/arch/x86_64/start64.asm
+++ b/Kernel/arch/x86_64/start64.asm
@@ -1,67 +1,90 @@
 ;
 ; Acess2 x86_64 Port
 ;
+%include "arch/x86_64/include/common.inc.asm"
 [bits 64]
+;KERNEL_BASE   equ     0xFFFF800000000000
+KERNEL_BASE    equ     0xFFFFFFFF80000000
+
+[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:
+       
+       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 + INITIAL_KSTACK_SIZE*0x1000
+       
        ; Call main
-       jmp $
-
-[global GetRIP]
-GetRIP:
-       mov rax, [rsp]
-       ret
+       mov edi, [gMultibootMagic - KERNEL_BASE]
+       mov esi, [gMultibootPtr - KERNEL_BASE]
+       call kmain
+       
+       cli
+.hlt:
+       hlt
+       jmp .hlt
 
 [global GetCPUNum]
 GetCPUNum:
-       str ax
-       mov gs, ax
        xor rax, rax
-       mov al, [gs:104]        ; End of TSS
+       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
+KSTACK_USERSTATE_SIZE  equ     (5+2+16+2)*8    ; IRET, ErrorNum, ErrorCode, GPRs, FS&GS
 [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
+       ; RDI - Handler
+       ; RSI - Kernel Stack
+       ; RDX - Signal num
        
        ;
        ; 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.
        ;
-       
+
+       xchg bx, bx     
        ; 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, [rsi-0x20]     ; Get user SP
+       xor eax, eax
        mov [rcx-16], rax
        sub rcx, 16
        
-       ; Restore Segment Registers
-       mov ax, 0x23
-       mov ds, ax
-       mov es, ax
+       ; Drop down to user mode
+       cli
+       mov rsp, rcx    ; Set SP
+       mov rcx, rdi    ; SYSRET IP
        
-       push 0x23       ; SS
-       push rcx        ; RSP
-       push 0x202      ; RFLAGS (IF and Rsvd)
-       push 0x1B       ; CS
-       push rbp        ; RIP
-       
-       iret
+       mov rdi, rdx    ; Argument for handler
+       mov r11, 0x202  ; RFlags
+       db 0x48
+       sysret
 
 ; int CallWithArgArray(void *Ptr, int NArgs, Uint *Args)
 ; Call a function passing the array as arguments
@@ -69,31 +92,55 @@ Proc_ReturnToUser:
 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
+       push r10
+       push r11
        
-       mov rax, [rbp+2*8]
+       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
-
-[section .bss]
-[global gInitialKernelStack]
-       resd    1024*1  ; 1 Page
-gInitialKernelStack:
-
+; vim: ft=nasm