// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of the License "Eclipse Public License v1.0"

 // which accompanies this distribution, and is available

 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

 //

 // Initial Contributors:

 // Nokia Corporation - initial contribution.

 //

 // Contributors:

 //

 // Description:

 // e32\klib\x86\cumem.cia

 // 

 //

 #include <x86.h>

 extern "C" {

 __NAKED__ void CopyInterSeg()

 //

 // Copy ECX bytes from DS:ESI to ES:EDI

 // Modifies EAX, EBX, ECX, EDX, ESI, EDI

 //

 	{

 	asm("pushfd");

 	asm("cld");				// assume forward copy initially

 	asm("test ecx,ecx");	//

 	asm("jz short memcopy0");// if length=0, nothing to do

 	asm("xor edx,edx");		//

 	asm("cmp edi,esi");		// compare source and dest addresses

 	asm("jc short memcopy1");// if dest<source, must go forwards

 	asm("std");				// else go backwards

 	asm("add esi,ecx");		// and start at end of block

 	asm("add edi,ecx");		//

 	asm("inc edx");			// edx=1 if backwards, 0 if forwards

 	asm("memcopy1:");

 	asm("cmp ecx,16");		// if length<16 don't bother with alignment check

 	asm("jc short memcopy2");//

 	asm("mov ebx,edi");		// ebx = destination address

 	asm("and ebx,3");		// ebx bottom 2 bits = alignment of destination wrt hardware bus

 	asm("jz short memcopy3");// if aligned, proceed with block move

 	asm("or edx,edx");		// check direction of move

 	asm("jnz short memcopy4");// if backwards, ebx = number of byte moves to align destination

 	asm("neg ebx");			// else number of byte moves = 4-ebx

 	asm("add ebx,4");		//

 	asm("memcopy4:");

 	asm("sub ecx,ebx");		// subtract number of bytes from length

 	asm("xchg ecx,ebx");	// temporarily put length in ebx

 	asm("sub edi,edx");		// adjust if backwards move

 	asm("sub esi,edx");		//

 	asm("rep movsb");		// move bytes to align destination

 	asm("add edi,edx");		// adjust if backwards move

 	asm("add esi,edx");		//

 	asm("mov ecx,ebx");		// length back into ecx

 	asm("memcopy3:");

 	asm("mov ebx,ecx");		// save length in ebx

 	asm("shl edx,2");		// adjustment 4 for backwards move

 	asm("shr ecx,2");		// number of dwords to move into ecx

 	asm("sub edi,edx");		// adjust if backwards move

 	asm("sub esi,edx");		//

 	asm("rep movsd");		// perform DWORD block move

 	asm("add edi,edx");		// adjust if backwards move

 	asm("add esi,edx");		//

 	asm("mov ecx,ebx");		// length back into ecx

 	asm("and ecx,3");		// number of remaining bytes to move

 	asm("jz short memcopy0");// if zero, we are finished

 	asm("shr edx,2");		// adjustment 1 for backwards move

 	asm("memcopy2:");		// *** come here for small move

 	asm("sub edi,edx");		// adjust if backwards move

 	asm("sub esi,edx");		//

 	asm("rep movsb");		// move remaining bytes

 	asm("memcopy0:");

 	asm("popfd");

 	asm("ret");				// finished - return value in EAX

 	}

 __NAKED__ void CopyInterSeg32()

 //

 // Copy ECX bytes from DS:ESI to ES:EDI

 // ECX, ESI and EDI are all multiples of 4

 // Modifies EAX, EBX, ECX, EDX, ESI, EDI

 //

 	{

 	asm("pushfd");

 	asm("cld");				//

 	asm("test ecx,ecx");	//

 	asm("jz short memmove0");// if length=0, nothing to do

 	asm("cmp edi,esi");		// compare source and dest addresses

 	asm("jc short memmove1");// if dest<source, must go forwards

 	asm("std");				// else go backwards

 	asm("lea esi,[esi+ecx-4]");	// and start at end of block - 4

 	asm("lea edi,[edi+ecx-4]");	//

 	asm("memmove1:");

 	asm("shr ecx,2");		// ecx now contains number of dwords to move

 	asm("rep movsd");		// do dword block move

 	asm("memmove0:");

 	asm("popfd");

 	asm("ret");				// finished - return value in EAX

 	}

 __NAKED__ void FillInterSeg()

 //

 // Fill ECX bytes at ES:EDI with AL

 // Modifies EAX, ECX, EDX, EDI

 //

 	{

 	asm("pushfd");

 	asm("cld");				// go forwards through array

 	asm("test ecx,ecx");	//

 	asm("jz short memfill0");// if length zero, nothing to do

 	asm("cmp ecx,8");			// if array very small, just do byte fills

 	asm("jb short memfill1");

 	asm("mov ah,al");		// repeat al in all bytes of eax

 	asm("movzx edx,ax");	//

 	asm("shl eax,16");		//

 	asm("or eax,edx");		//

 	asm("mov edx,ecx");		// length into edx

 	// ecx = number of byte fills to align = 4-(edi mod 4)

 	asm("mov ecx,4");		

 	asm("sub ecx,edi");		//

 	asm("and ecx,3");		//

 	asm("jz short memfill2");// if already aligned, proceed to dword fill

 	asm("sub edx,ecx");		// subtract alignment bytes from length

 	asm("rep stosb");		// do byte fills to align

 	asm("memfill2:");

 	asm("mov ecx,edx");		// length remaining into ecx

 	asm("shr ecx,2");		// number of dwords to fill into ecx

 	asm("rep stosd");		// perform dword fill

 	asm("mov ecx,edx");		// calculate number of leftover bytes

 	asm("and ecx,3");		// in ecx

 	asm("jz short memfill0");// if none left, exit

 	asm("memfill1:");

 	asm("rep stosb");		// do byte fills to make up correct length

 	asm("memfill0:");

 	asm("popfd");

 	asm("ret");

 	}

 /**	Reads the current thread's memory space with appropriate permissions.

 Performs a memcpy(aKernAddr, aAddr, aLength).

 The reads are performed	using requestor privilege level from GS, ie equal

 to the privilege level of the caller of the Exec:: function.

 Note that source and destination areas may not overlap.

 @param	aKernAddr	Destination address in kernel memory.

 @param	aAddr		Source address in kernel or user memory.

 @param	aLength		Number of bytes to copy.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void kumemget(TAny* /*aKernAddr*/, const TAny* /*aAddr*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push ds");

 	asm("mov edi, [esp+20]");

 	asm("mov esi, [esp+24]");

 	asm("mov ecx, [esp+28]");

 	asm("mov ax, gs");

 	asm("mov ds, ax");

 	asm("call %a0": : "i"(&CopyInterSeg));

 	asm("pop ds");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 /**	Reads the current thread's memory space with user permissions.

 Performs a memcpy(aKernAddr, aUserAddr, aLength).

 The reads are performed with ring 3 RPL.

 Note that source and destination areas may not overlap.

 @param	aKernAddr	Destination address in kernel memory.

 @param	aUserAddr	Source address in user memory.

 @param	aLength		Number of bytes to copy.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void umemget(TAny* /*aKernAddr*/, const TAny* /*aUserAddr*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push ds");

 	asm("mov edi, [esp+20]");

 	asm("mov esi, [esp+24]");

 	asm("mov ecx, [esp+28]");

 	asm("mov eax, %0": : "i"(RING3_DS));

 	asm("mov ds, ax");

 	asm("call %a0": : "i"(&CopyInterSeg));

 	asm("pop ds");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 /**	Does a word-aligned read of the current thread's memory space with appropriate permissions.

 Performs a memcpy(aKernAddr, aAddr, aLength).

 The reads are performed	using requestor privilege level from GS, ie equal

 to the privilege level of the caller of the Exec:: function.

 Note that source and destination areas may not overlap.

 @param	aKernAddr	Destination address in kernel memory, must be 4-byte aligned.

 @param	aAddr		Source address in kernel or user memory, must be 4-byte aligned.

 @param	aLength		Number of bytes to copy, must be a multiple of 4.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void kumemget32(TAny* /*aKernAddr*/, const TAny* /*aAddr*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push ds");

 	asm("mov edi, [esp+20]");

 	asm("mov esi, [esp+24]");

 	asm("mov ecx, [esp+28]");

 	asm("mov ax, gs");

 	asm("mov ds, ax");

 	asm("call %a0": : "i"(&CopyInterSeg32));

 	asm("pop ds");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 /**	Does a word-aligned read of the current thread's memory space with user permissions.

 Performs a memcpy(aKernAddr, aUserAddr, aLength).

 The reads are performed with ring 3 RPL.

 Note that source and destination areas may not overlap.

 @param	aKernAddr	Destination address in kernel memory, must be 4-byte aligned.

 @param	aUserAddr	Source address in user memory, must be 4-byte aligned.

 @param	aLength		Number of bytes to copy, must be a multiple of 4.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void umemget32(TAny* /*aKernAddr*/, const TAny* /*aUserAddr*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push ds");

 	asm("mov edi, [esp+20]");

 	asm("mov esi, [esp+24]");

 	asm("mov ecx, [esp+28]");

 	asm("mov eax, %0": : "i"(RING3_DS));

 	asm("mov ds, ax");

 	asm("call %a0": : "i"(&CopyInterSeg32));

 	asm("pop ds");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 /**	Writes to the current thread's memory space with appropriate permissions.

 Performs a memcpy(aAddr, aKernAddr, aLength).

 The writes are performed using requestor privilege level from GS, ie equal

 to the privilege level of the caller of the Exec:: function.

 Note that source and destination areas may not overlap.

 @param	aAddr		Destination address in kernel or user memory.

 @param	aKernAddr	Source address in kernel memory.

 @param	aLength		Number of bytes to copy.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void kumemput(TAny* /*aAddr*/, const TAny* /*aKernAddr*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push es");

 	asm("mov edi, [esp+20]");

 	asm("mov esi, [esp+24]");

 	asm("mov ecx, [esp+28]");

 	asm("mov ax, gs");

 	asm("mov es, ax");

 	asm("call %a0": : "i"(&CopyInterSeg));

 	asm("pop es");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 /**	Writes to the current thread's memory space with user permissions.

 Performs a memcpy(aAddr, aKernAddr, aLength).

 The writes are performed with ring 3 RPL.

 Note that source and destination areas may not overlap.

 @param	aUserAddr	Destination address in user memory.

 @param	aKernAddr	Source address in kernel memory.

 @param	aLength		Number of bytes to copy.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void umemput(TAny* /*aUserAddr*/, const TAny* /*aKernAddr*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push es");

 	asm("mov edi, [esp+20]");

 	asm("mov esi, [esp+24]");

 	asm("mov ecx, [esp+28]");

 	asm("mov eax, %0": : "i"(RING3_DS));

 	asm("mov es, ax");

 	asm("call %a0": : "i"(&CopyInterSeg));

 	asm("pop es");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 /**	Does a word-aligned write to the current thread's memory space with appropriate permissions.

 Performs a memcpy(aAddr, aKernAddr, aLength).

 The writes are performed using requestor privilege level from GS, ie equal

 to the privilege level of the caller of the Exec:: function.

 Note that source and destination areas may not overlap.

 @param	aAddr		Destination address in kernel or user memory, must be 4-byte aligned.

 @param	aKernAddr	Source address in kernel memory, must be 4-byte aligned.

 @param	aLength		Number of bytes to copy, must be a multiple of 4.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void kumemput32(TAny* /*aAddr*/, const TAny* /*aKernAddr*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push es");

 	asm("mov edi, [esp+20]");

 	asm("mov esi, [esp+24]");

 	asm("mov ecx, [esp+28]");

 	asm("mov ax, gs");

 	asm("mov es, ax");

 	asm("call %a0": : "i"(&CopyInterSeg32));

 	asm("pop es");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 /**	Does a word-aligned write to the current thread's memory space with user permissions.

 Performs a memcpy(aAddr, aKernAddr, aLength).

 The writes are performed with ring 3 RPL.

 Note that source and destination areas may not overlap.

 @param	aUserAddr	Destination address in user memory, must be 4-byte aligned.

 @param	aKernAddr	Source address in kernel memory, must be 4-byte aligned.

 @param	aLength		Number of bytes to copy, must be a multiple of 4.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void umemput32(TAny* /*aUserAddr*/, const TAny* /*aKernAddr*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push es");

 	asm("mov edi, [esp+20]");

 	asm("mov esi, [esp+24]");

 	asm("mov ecx, [esp+28]");

 	asm("mov eax, %0": : "i"(RING3_DS));

 	asm("mov es, ax");

 	asm("call %a0": : "i"(&CopyInterSeg32));

 	asm("pop es");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 /**	Fills the current thread's memory space with appropriate permissions.

 Performs a memset(aAddr, aValue, aLength).

 The writes are performed using requestor privilege level from GS, ie equal

 to the privilege level of the caller of the Exec:: function.

 @param	aAddr		Destination address in kernel or user memory.

 @param	aValue		Value to write to each byte.

 @param	aLength		Number of bytes to fill.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void kumemset(TAny* /*aAddr*/, const TUint8 /*aValue*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push es");

 	asm("mov edi, [esp+12]");

 	asm("mov eax, [esp+16]");

 	asm("mov ecx, [esp+20]");

 	asm("mov dx, gs");

 	asm("mov es, dx");

 	asm("call %a0": :"i"(&FillInterSeg));

 	asm("pop es");

 	asm("pop edi");

 	asm("ret");

 	}

 /**	Fills the current thread's memory space with user permissions.

 Performs a memset(aUserAddr, aValue, aLength).

 The writes are performed with ring 3 RPL.

 @param	aUserAddr	Destination address in user memory.

 @param	aValue		Value to write to each byte.

 @param	aLength		Number of bytes to fill.

 @pre    Call in a thread context.

 @pre    Kernel must be unlocked.

 @pre	Must be called under an XTRAP harness, or calling thread must not be

 in a critical section.

 */

 EXPORT_C __NAKED__ void umemset(TAny* /*aUserAddr*/, const TUint8 /*aValue*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push es");

 	asm("mov edi, [esp+12]");

 	asm("mov eax, [esp+16]");

 	asm("mov ecx, [esp+20]");

 	asm("mov edx, %0": : "i"(RING3_DS));

 	asm("mov es, dx");

 	asm("call %a0": :"i"(&FillInterSeg));

 	asm("pop es");

 	asm("pop edi");

 	asm("ret");

 	}

 __NAKED__ void uumemcpy32(TAny* /*aUserDst*/, const TAny* /*aUserSrc*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push ds");

 	asm("push es");

 	asm("mov edi, [esp+24]");

 	asm("mov esi, [esp+28]");

 	asm("mov ecx, [esp+32]");

 	asm("mov ax, gs");

 	asm("mov ds, ax");

 	asm("mov es, ax");

 	asm("call %a0": : "i"(&CopyInterSeg32));

 	asm("pop es");

 	asm("pop ds");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 __NAKED__ void uumemcpy(TAny* /*aUserDst*/, const TAny* /*aUserSrc*/, TInt /*aLength*/)

 	{

 	asm("push edi");

 	asm("push esi");

 	asm("push ebx");

 	asm("push ds");

 	asm("push es");

 	asm("mov edi, [esp+24]");

 	asm("mov esi, [esp+28]");

 	asm("mov ecx, [esp+32]");

 	asm("mov ax, gs");

 	asm("mov ds, ax");

 	asm("mov es, ax");

 	asm("call %a0": : "i"(&CopyInterSeg));

 	asm("pop es");

 	asm("pop ds");

 	asm("pop ebx");

 	asm("pop esi");

 	asm("pop edi");

 	asm("ret");

 	}

 }