X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86_64%2Fstart64.asm;h=b0a85868ceb4b5ba4ad60056d6d3f3d96d38396f;hb=952891ddb96a341c0e24ecb7dec6361c7bbeaece;hp=bf7293b6dcc17e102f5c2d56dd676c68ce9ab4f0;hpb=33bcf4b3feb0e5e4548548bf3d2a50c52ffb6115;p=tpg%2Facess2.git diff --git a/Kernel/arch/x86_64/start64.asm b/Kernel/arch/x86_64/start64.asm index bf7293b6..b0a85868 100644 --- a/Kernel/arch/x86_64/start64.asm +++ b/Kernel/arch/x86_64/start64.asm @@ -2,14 +2,172 @@ ; 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: + ; 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, 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: + 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 + +[section .bss] +[global gInitialKernelStack] + resd 1024*4 ; 4 Pages +gInitialKernelStack: +