/*
* Relay calls helper routines
*
* Copyright 1993 Robert J. Amstadt
* Copyright 1995 Martin von Loewis
* Copyright 1995, 1996, 1997 Alexandre Julliard
* Copyright 1997 Eric Youngdale
* Copyright 1999 Ulrich Weigand
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include "config.h"
#include "wine/port.h"
#include <ctype.h>
#include <stdarg.h>
#include "build.h"
/* offset of the stack pointer relative to %fs:(0) */
#define STACKOFFSET 0x10c /* FIELD_OFFSET(TEB,SystemReserved1) */
/* fix this if the x86_thread_data structure is changed */
#define GS_OFFSET 0x1d8 /* FIELD_OFFSET(TEB,SystemReserved2) + FIELD_OFFSET(struct x86_thread_data,gs) */
static void function_header( const char *name )
{
output( "\n\t.align %d\n", get_alignment(4) );
output( "\t%s\n", func_declaration(name) );
output( "%s\n", asm_globl(name) );
}
/*******************************************************************
* BuildCallFrom16Core
*
* This routine builds the core routines used in 16->32 thunks:
* CallFrom16Word, CallFrom16Long, CallFrom16Register, and CallFrom16Thunk.
*
* These routines are intended to be called via a far call (with 32-bit
* operand size) from 16-bit code. The 16-bit code stub must push %bp,
* the 32-bit entry point to be called, and the argument conversion
* routine to be used (see stack layout below).
*
* The core routine completes the STACK16FRAME on the 16-bit stack and
* switches to the 32-bit stack. Then, the argument conversion routine
* is called; it gets passed the 32-bit entry point and a pointer to the
* 16-bit arguments (on the 16-bit stack) as parameters. (You can either
* use conversion routines automatically generated by BuildCallFrom16,
* or write your own for special purposes.)
*
* The conversion routine must call the 32-bit entry point, passing it
* the converted arguments, and return its return value to the core.
* After the conversion routine has returned, the core switches back
* to the 16-bit stack, converts the return value to the DX:AX format
* (CallFrom16Long), and returns to the 16-bit call stub. All parameters,
* including %bp, are popped off the stack.
*
* The 16-bit call stub now returns to the caller, popping the 16-bit
* arguments if necessary (pascal calling convention).
*
* In the case of a 'register' function, CallFrom16Register fills a
* CONTEXT86 structure with the values all registers had at the point
* the first instruction of the 16-bit call stub was about to be
* executed. A pointer to this CONTEXT86 is passed as third parameter
* to the argument conversion routine, which typically passes it on
* to the called 32-bit entry point.
*
* CallFrom16Thunk is a special variant used by the implementation of
* the Win95 16->32 thunk functions C16ThkSL and C16ThkSL01 and is
* implemented as follows:
* On entry, the EBX register is set up to contain a flat pointer to the
* 16-bit stack such that EBX+22 points to the first argument.
* Then, the entry point is called, while EBP is set up to point
* to the return address (on the 32-bit stack).
* The called function returns with CX set to the number of bytes
* to be popped of the caller's stack.
*
* Stack layout upon entry to the core routine (STACK16FRAME):
* ... ...
* (sp+24) word first 16-bit arg
* (sp+22) word cs
* (sp+20) word ip
* (sp+18) word bp
* (sp+14) long 32-bit entry point (reused for Win16 mutex recursion count)
* (sp+12) word ip of actual entry point (necessary for relay debugging)
* (sp+8) long relay (argument conversion) function entry point
* (sp+4) long cs of 16-bit entry point
* (sp) long ip of 16-bit entry point
*
* Added on the stack:
* (sp-2) word saved gs
* (sp-4) word saved fs
* (sp-6) word saved es
* (sp-8) word saved ds
* (sp-12) long saved ebp
* (sp-16) long saved ecx
* (sp-20) long saved edx
* (sp-24) long saved previous stack
*/
static void BuildCallFrom16Core( int reg_func, int thunk )
{
/* Function header */
if (thunk) function_header( "__wine_call_from_16_thunk" );
else if (reg_func) function_header( "__wine_call_from_16_regs" );
else function_header( "__wine_call_from_16" );
/* Create STACK16FRAME (except STACK32FRAME link) */
output( "\tpushw %%gs\n" );
output( "\tpushw %%fs\n" );
output( "\tpushw %%es\n" );
output( "\tpushw %%ds\n" );
output( "\tpushl %%ebp\n" );
output( "\tpushl %%ecx\n" );
output( "\tpushl %%edx\n" );
/* Save original EFlags register */
if (reg_func) output( "\tpushfl\n" );
if ( UsePIC )
{
output( "\tcall 1f\n" );
output( "1:\tpopl %%ecx\n" );
output( "\t.byte 0x2e\n\tmovl %s-1b(%%ecx),%%edx\n", asm_name("CallTo16_DataSelector") );
}
else
output( "\t.byte 0x2e\n\tmovl %s,%%edx\n", asm_name("CallTo16_DataSelector") );
/* Load 32-bit segment registers */
output( "\tmovw %%dx, %%ds\n" );
output( "\tmovw %%dx, %%es\n" );
if ( UsePIC )
output( "\tmovw %s-1b(%%ecx), %%fs\n", asm_name("CallTo16_TebSelector") );
else
output( "\tmovw %s, %%fs\n", asm_name("CallTo16_TebSelector") );
output( "\t.byte 0x64\n\tmov (%d),%%gs\n", GS_OFFSET );
/* Translate STACK16FRAME base to flat offset in %edx */
output( "\tmovw %%ss, %%dx\n" );
output( "\tandl $0xfff8, %%edx\n" );
output( "\tshrl $1, %%edx\n" );
if (UsePIC)
output( "\taddl .Lwine_ldt_copy_ptr-1b(%%ecx),%%edx\n" );
else
output( "\taddl .Lwine_ldt_copy_ptr,%%edx\n" );
output( "\tmovl (%%edx), %%edx\n" );
output( "\tmovzwl %%sp, %%ebp\n" );
output( "\tleal %d(%%ebp,%%edx), %%edx\n", reg_func ? 0 : -4 );
/* Get saved flags into %ecx */
if (reg_func) output( "\tpopl %%ecx\n" );
/* Get the 32-bit stack pointer from the TEB and complete STACK16FRAME */
output( "\t.byte 0x64\n\tmovl (%d), %%ebp\n", STACKOFFSET );
output( "\tpushl %%ebp\n" );
/* Switch stacks */
output( "\t.byte 0x64\n\tmovw %%ss, (%d)\n", STACKOFFSET + 2 );
output( "\t.byte 0x64\n\tmovw %%sp, (%d)\n", STACKOFFSET );
output( "\tpushl %%ds\n" );
output( "\tpopl %%ss\n" );
output( "\tmovl %%ebp, %%esp\n" );
output( "\taddl $0x20,%%ebp\n"); /* FIELD_OFFSET(STACK32FRAME,ebp) */
/* At this point:
STACK16FRAME is completely set up
DS, ES, SS: flat data segment
FS: current TEB
ESP: points to last STACK32FRAME
EBP: points to ebp member of last STACK32FRAME
EDX: points to current STACK16FRAME
ECX: contains saved flags
all other registers: unchanged */
/* Special case: C16ThkSL stub */
if ( thunk )
{
/* Set up registers as expected and call thunk */
output( "\tleal 0x1a(%%edx),%%ebx\n" ); /* sizeof(STACK16FRAME)-22 */
output( "\tleal -4(%%esp), %%ebp\n" );
output( "\tcall *0x26(%%edx)\n"); /* FIELD_OFFSET(STACK16FRAME,entry_point) */
/* Switch stack back */
output( "\t.byte 0x64\n\tmovw (%d), %%ss\n", STACKOFFSET+2 );
output( "\t.byte 0x64\n\tmovzwl (%d), %%esp\n", STACKOFFSET );
output( "\t.byte 0x64\n\tpopl (%d)\n", STACKOFFSET );
/* Restore registers and return directly to caller */
output( "\taddl $8, %%esp\n" );
output( "\tpopl %%ebp\n" );
output( "\tpopw %%ds\n" );
output( "\tpopw %%es\n" );
output( "\tpopw %%fs\n" );
output( "\tpopw %%gs\n" );
output( "\taddl $20, %%esp\n" );
output( "\txorb %%ch, %%ch\n" );
output( "\tpopl %%ebx\n" );
output( "\taddw %%cx, %%sp\n" );
output( "\tpush %%ebx\n" );
output( "\t.byte 0x66\n" );
output( "\tlret\n" );
output_function_size( "__wine_call_from_16_thunk" );
return;
}
/* Build register CONTEXT */
if ( reg_func )
{
output( "\tsubl $0x2cc,%%esp\n" ); /* sizeof(CONTEXT86) */
output( "\tmovl %%ecx,0xc0(%%esp)\n" ); /* EFlags */
output( "\tmovl %%eax,0xb0(%%esp)\n" ); /* Eax */
output( "\tmovl %%ebx,0xa4(%%esp)\n" ); /* Ebx */
output( "\tmovl %%esi,0xa0(%%esp)\n" ); /* Esi */
output( "\tmovl %%edi,0x9c(%%esp)\n" ); /* Edi */
output( "\tmovl 0x0c(%%edx),%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,ebp) */
output( "\tmovl %%eax,0xb4(%%esp)\n" ); /* Ebp */
output( "\tmovl 0x08(%%edx),%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,ecx) */
output( "\tmovl %%eax,0xac(%%esp)\n" ); /* Ecx */
output( "\tmovl 0x04(%%edx),%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,edx) */
output( "\tmovl %%eax,0xa8(%%esp)\n" ); /* Edx */
output( "\tmovzwl 0x10(%%edx),%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,ds) */
output( "\tmovl %%eax,0x98(%%esp)\n" ); /* SegDs */
output( "\tmovzwl 0x12(%%edx),%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,es) */
output( "\tmovl %%eax,0x94(%%esp)\n" ); /* SegEs */
output( "\tmovzwl 0x14(%%edx),%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,fs) */
output( "\tmovl %%eax,0x90(%%esp)\n" ); /* SegFs */
output( "\tmovzwl 0x16(%%edx),%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,gs) */
output( "\tmovl %%eax,0x8c(%%esp)\n" ); /* SegGs */
output( "\tmovzwl 0x2e(%%edx),%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,cs) */
output( "\tmovl %%eax,0xbc(%%esp)\n" ); /* SegCs */
output( "\tmovzwl 0x2c(%%edx),%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,ip) */
output( "\tmovl %%eax,0xb8(%%esp)\n" ); /* Eip */
output( "\t.byte 0x64\n\tmovzwl (%d), %%eax\n", STACKOFFSET+2 );
output( "\tmovl %%eax,0xc8(%%esp)\n" ); /* SegSs */
output( "\t.byte 0x64\n\tmovzwl (%d), %%eax\n", STACKOFFSET );
output( "\taddl $0x2c,%%eax\n"); /* FIELD_OFFSET(STACK16FRAME,ip) */
output( "\tmovl %%eax,0xc4(%%esp)\n" ); /* Esp */
#if 0
output( "\tfsave 0x1c(%%esp)\n" ); /* FloatSave */
#endif
/* Push address of CONTEXT86 structure -- popped by the relay routine */
output( "\tmovl %%esp,%%eax\n" );
output( "\tandl $~15,%%esp\n" );
output( "\tsubl $4,%%esp\n" );
output( "\tpushl %%eax\n" );
}
else
{
output( "\tsubl $8,%%esp\n" );
output( "\tandl $~15,%%esp\n" );
output( "\taddl $8,%%esp\n" );
}
/* Call relay routine (which will call the API entry point) */
output( "\tleal 0x30(%%edx),%%eax\n" ); /* sizeof(STACK16FRAME) */
output( "\tpushl %%eax\n" );
output( "\tpushl 0x26(%%edx)\n"); /* FIELD_OFFSET(STACK16FRAME,entry_point) */
output( "\tcall *0x20(%%edx)\n"); /* FIELD_OFFSET(STACK16FRAME,relay) */
if ( reg_func )
{
output( "\tleal -748(%%ebp),%%ebx\n" ); /* sizeof(CONTEXT) + FIELD_OFFSET(STACK32FRAME,ebp) */
/* Switch stack back */
output( "\t.byte 0x64\n\tmovw (%d), %%ss\n", STACKOFFSET+2 );
output( "\t.byte 0x64\n\tmovzwl (%d), %%esp\n", STACKOFFSET );
output( "\t.byte 0x64\n\tpopl (%d)\n", STACKOFFSET );
/* Get return address to CallFrom16 stub */
output( "\taddw $0x14,%%sp\n" ); /* FIELD_OFFSET(STACK16FRAME,callfrom_ip)-4 */
output( "\tpopl %%eax\n" );
output( "\tpopl %%edx\n" );
/* Restore all registers from CONTEXT */
output( "\tmovw 0xc8(%%ebx),%%ss\n"); /* SegSs */
output( "\tmovl 0xc4(%%ebx),%%esp\n"); /* Esp */
output( "\taddl $4, %%esp\n" ); /* room for final return address */
output( "\tpushw 0xbc(%%ebx)\n"); /* SegCs */
output( "\tpushw 0xb8(%%ebx)\n"); /* Eip */
output( "\tpushl %%edx\n" );
output( "\tpushl %%eax\n" );
output( "\tpushl 0xc0(%%ebx)\n"); /* EFlags */
output( "\tpushl 0x98(%%ebx)\n"); /* SegDs */
output( "\tpushl 0x94(%%ebx)\n"); /* SegEs */
output( "\tpopl %%es\n" );
output( "\tpushl 0x90(%%ebx)\n"); /* SegFs */
output( "\tpopl %%fs\n" );
output( "\tpushl 0x8c(%%ebx)\n"); /* SegGs */
output( "\tpopl %%gs\n" );
output( "\tmovl 0xb4(%%ebx),%%ebp\n"); /* Ebp */
output( "\tmovl 0xa0(%%ebx),%%esi\n"); /* Esi */
output( "\tmovl 0x9c(%%ebx),%%edi\n"); /* Edi */
output( "\tmovl 0xb0(%%ebx),%%eax\n"); /* Eax */
output( "\tmovl 0xa8(%%ebx),%%edx\n"); /* Edx */
output( "\tmovl 0xac(%%ebx),%%ecx\n"); /* Ecx */
output( "\tmovl 0xa4(%%ebx),%%ebx\n"); /* Ebx */
output( "\tpopl %%ds\n" );
output( "\tpopfl\n" );
output( "\tlret\n" );
output_function_size( "__wine_call_from_16_regs" );
}
else
{
/* Switch stack back */
output( "\t.byte 0x64\n\tmovw (%d), %%ss\n", STACKOFFSET+2 );
output( "\t.byte 0x64\n\tmovzwl (%d), %%esp\n", STACKOFFSET );
output( "\t.byte 0x64\n\tpopl (%d)\n", STACKOFFSET );
/* Restore registers */
output( "\tpopl %%edx\n" );
output( "\tpopl %%ecx\n" );
output( "\tpopl %%ebp\n" );
output( "\tpopw %%ds\n" );
output( "\tpopw %%es\n" );
output( "\tpopw %%fs\n" );
output( "\tpopw %%gs\n" );
/* Return to return stub which will return to caller */
output( "\tlret $12\n" );
output_function_size( "__wine_call_from_16" );
}
}
/*******************************************************************
* BuildCallTo16Core
*
* This routine builds the core routines used in 32->16 thunks:
*
* extern DWORD WINAPI wine_call_to_16( FARPROC16 target, DWORD cbArgs, PEXCEPTION_HANDLER handler );
* extern void WINAPI wine_call_to_16_regs( CONTEXT86 *context, DWORD cbArgs, PEXCEPTION_HANDLER handler );
*
* These routines can be called directly from 32-bit code.
*
* All routines expect that the 16-bit stack contents (arguments) and the
* return address (segptr to CallTo16_Ret) were already set up by the
* caller; nb_args must contain the number of bytes to be conserved. The
* 16-bit SS:SP will be set accordingly.
*
* All other registers are either taken from the CONTEXT86 structure
* or else set to default values. The target routine address is either
* given directly or taken from the CONTEXT86.
*/
static void BuildCallTo16Core( int reg_func )
{
const char *name = reg_func ? "wine_call_to_16_regs" : "wine_call_to_16";
const char *func_name = is_pe() ? strmake( "%s@12", name ) : name;
/* Function header */
function_header( func_name );
/* Function entry sequence */
output_cfi( ".cfi_startproc" );
output( "\tpushl %%ebp\n" );
output_cfi( ".cfi_adjust_cfa_offset 4" );
output_cfi( ".cfi_rel_offset %%ebp,0" );
output( "\tmovl %%esp, %%ebp\n" );
output_cfi( ".cfi_def_cfa_register %%ebp" );
/* Save the 32-bit registers */
output( "\tpushl %%ebx\n" );
output_cfi( ".cfi_rel_offset %%ebx,-4" );
output( "\tpushl %%esi\n" );
output_cfi( ".cfi_rel_offset %%esi,-8" );
output( "\tpushl %%edi\n" );
output_cfi( ".cfi_rel_offset %%edi,-12" );
output( "\t.byte 0x64\n\tmov %%gs,(%d)\n", GS_OFFSET );
/* Setup exception frame */
output( "\t.byte 0x64\n\tpushl (%d)\n", STACKOFFSET );
output( "\tpushl 16(%%ebp)\n" ); /* handler */
output( "\t.byte 0x64\n\tpushl (0)\n" );
output( "\t.byte 0x64\n\tmovl %%esp,(0)\n" );
/* Call the actual CallTo16 routine (simulate a lcall) */
output( "\tpushl %%cs\n" );
output( "\tcall .L%s\n", name );
/* Remove exception frame */
output( "\t.byte 0x64\n\tpopl (0)\n" );
output( "\taddl $4, %%esp\n" );
output( "\t.byte 0x64\n\tpopl (%d)\n", STACKOFFSET );
if ( !reg_func )
{
/* Convert return value */
output( "\tandl $0xffff,%%eax\n" );
output( "\tshll $16,%%edx\n" );
output( "\torl %%edx,%%eax\n" );
}
else
{
/*
* Modify CONTEXT86 structure to contain new values
*
* NOTE: We restore only EAX, EBX, ECX, EDX, EBP, and ESP.
* The segment registers as well as ESI and EDI should
* not be modified by a well-behaved 16-bit routine in
* any case. [If necessary, we could restore them as well,
* at the cost of a somewhat less efficient return path.]
*/
output( "\tmovl 0x14(%%esp),%%edi\n" ); /* FIELD_OFFSET(STACK32FRAME,target) - FIELD_OFFSET(STACK32FRAME,edi) */
/* everything above edi has been popped already */
output( "\tmovl %%eax,0xb0(%%edi)\n"); /* Eax */
output( "\tmovl %%ebx,0xa4(%%edi)\n"); /* Ebx */
output( "\tmovl %%ecx,0xac(%%edi)\n"); /* Ecx */
output( "\tmovl %%edx,0xa8(%%edi)\n"); /* Edx */
output( "\tmovl %%ebp,0xb4(%%edi)\n"); /* Ebp */
output( "\tmovl %%esi,0xc4(%%edi)\n"); /* Esp */
/* The return glue code saved %esp into %esi */
}
/* Restore the 32-bit registers */
output( "\tpopl %%edi\n" );
output_cfi( ".cfi_same_value %%edi" );
output( "\tpopl %%esi\n" );
output_cfi( ".cfi_same_value %%esi" );
output( "\tpopl %%ebx\n" );
output_cfi( ".cfi_same_value %%ebx" );
/* Function exit sequence */
output( "\tpopl %%ebp\n" );
output_cfi( ".cfi_def_cfa %%esp,4" );
output_cfi( ".cfi_same_value %%ebp" );
output( "\tret $12\n" );
output_cfi( ".cfi_endproc" );
/* Start of the actual CallTo16 routine */
output( ".L%s:\n", name );
/* Switch to the 16-bit stack */
output( "\tmovl %%esp,%%edx\n" );
output( "\t.byte 0x64\n\tmovw (%d),%%ss\n", STACKOFFSET + 2);
output( "\t.byte 0x64\n\tmovw (%d),%%sp\n", STACKOFFSET );
output( "\t.byte 0x64\n\tmovl %%edx,(%d)\n", STACKOFFSET );
/* Make %bp point to the previous stackframe (built by CallFrom16) */
output( "\tmovzwl %%sp,%%ebp\n" );
output( "\tleal 0x2a(%%ebp),%%ebp\n"); /* FIELD_OFFSET(STACK16FRAME,bp) */
/* Add the specified offset to the new sp */
output( "\tsubw 0x2c(%%edx), %%sp\n"); /* FIELD_OFFSET(STACK32FRAME,nb_args) */
if (reg_func)
{
/* Push the called routine address */
output( "\tmovl 0x28(%%edx),%%edx\n"); /* FIELD_OFFSET(STACK32FRAME,target) */
output( "\tpushw 0xbc(%%edx)\n"); /* SegCs */
output( "\tpushw 0xb8(%%edx)\n"); /* Eip */
/* Get the registers */
output( "\tpushw 0x98(%%edx)\n"); /* SegDs */
output( "\tpushl 0x94(%%edx)\n"); /* SegEs */
output( "\tpopl %%es\n" );
output( "\tmovl 0xb4(%%edx),%%ebp\n"); /* Ebp */
output( "\tmovl 0xa0(%%edx),%%esi\n"); /* Esi */
output( "\tmovl 0x9c(%%edx),%%edi\n"); /* Edi */
output( "\tmovl 0xb0(%%edx),%%eax\n"); /* Eax */
output( "\tmovl 0xa4(%%edx),%%ebx\n"); /* Ebx */
output( "\tmovl 0xac(%%edx),%%ecx\n"); /* Ecx */
output( "\tmovl 0xa8(%%edx),%%edx\n"); /* Edx */
/* Get the 16-bit ds */
output( "\tpopw %%ds\n" );
}
else /* not a register function */
{
/* Push the called routine address */
output( "\tpushl 0x28(%%edx)\n"); /* FIELD_OFFSET(STACK32FRAME,target) */
/* Set %fs and %gs to the value saved by the last CallFrom16 */
output( "\tpushw -22(%%ebp)\n" ); /* FIELD_OFFSET(STACK16FRAME,fs)-FIELD_OFFSET(STACK16FRAME,bp) */
output( "\tpopw %%fs\n" );
output( "\tpushw -20(%%ebp)\n" ); /* FIELD_OFFSET(STACK16FRAME,gs)-FIELD_OFFSET(STACK16FRAME,bp) */
output( "\tpopw %%gs\n" );
/* Set %ds and %es (and %ax just in case) equal to %ss */
output( "\tmovw %%ss,%%ax\n" );
output( "\tmovw %%ax,%%ds\n" );
output( "\tmovw %%ax,%%es\n" );
}
/* Jump to the called routine */
output( "\t.byte 0x66\n" );
output( "\tlret\n" );
/* Function footer */
output_function_size( func_name );
}
/*******************************************************************
* BuildRet16Func
*
* Build the return code for 16-bit callbacks
*/
static void BuildRet16Func(void)
{
function_header( "__wine_call_to_16_ret" );
/* Save %esp into %esi */
output( "\tmovl %%esp,%%esi\n" );
/* Restore 32-bit segment registers */
output( "\t.byte 0x2e\n\tmovl %s", asm_name("CallTo16_DataSelector") );
output( "-%s,%%edi\n", asm_name("__wine_call16_start") );
output( "\tmovw %%di,%%ds\n" );
output( "\tmovw %%di,%%es\n" );
output( "\t.byte 0x2e\n\tmov %s", asm_name("CallTo16_TebSelector") );
output( "-%s,%%fs\n", asm_name("__wine_call16_start") );
output( "\t.byte 0x64\n\tmov (%d),%%gs\n", GS_OFFSET );
/* Restore the 32-bit stack */
output( "\tmovw %%di,%%ss\n" );
output( "\t.byte 0x64\n\tmovl (%d),%%esp\n", STACKOFFSET );
/* Return to caller */
output( "\tlret\n" );
output_function_size( "__wine_call_to_16_ret" );
}
/*******************************************************************
* BuildCallTo32CBClient
*
* Call a CBClient relay stub from 32-bit code (KERNEL.620).
*
* Since the relay stub is itself 32-bit, this should not be a problem;
* unfortunately, the relay stubs are expected to switch back to a
* 16-bit stack (and 16-bit code) after completion :-(
*
* This would conflict with our 16- vs. 32-bit stack handling, so
* we simply switch *back* to our 32-bit stack before returning to
* the caller ...
*
* The CBClient relay stub expects to be called with the following
* 16-bit stack layout, and with ebp and ebx pointing into the 16-bit
* stack at the designated places:
*
* ...
* (ebp+14) original arguments to the callback routine
* (ebp+10) far return address to original caller
* (ebp+6) Thunklet target address
* (ebp+2) Thunklet relay ID code
* (ebp) BP (saved by CBClientGlueSL)
* (ebp-2) SI (saved by CBClientGlueSL)
* (ebp-4) DI (saved by CBClientGlueSL)
* (ebp-6) DS (saved by CBClientGlueSL)
*
* ... buffer space used by the 16-bit side glue for temp copies
*
* (ebx+4) far return address to 16-bit side glue code
* (ebx) saved 16-bit ss:sp (pointing to ebx+4)
*
* The 32-bit side glue code accesses both the original arguments (via ebp)
* and the temporary copies prepared by the 16-bit side glue (via ebx).
* After completion, the stub will load ss:sp from the buffer at ebx
* and perform a far return to 16-bit code.
*
* To trick the relay stub into returning to us, we replace the 16-bit
* return address to the glue code by a cs:ip pair pointing to our
* return entry point (the original return address is saved first).
* Our return stub thus called will then reload the 32-bit ss:esp and
* return to 32-bit code (by using and ss:esp value that we have also
* pushed onto the 16-bit stack before and a cs:eip values found at
* that position on the 32-bit stack). The ss:esp to be restored is
* found relative to the 16-bit stack pointer at:
*
* (ebx-4) ss (flat)
* (ebx-8) sp (32-bit stack pointer)
*
* The second variant of this routine, CALL32_CBClientEx, which is used
* to implement KERNEL.621, has to cope with yet another problem: Here,
* the 32-bit side directly returns to the caller of the CBClient thunklet,
* restoring registers saved by CBClientGlueSL and cleaning up the stack.
* As we have to return to our 32-bit code first, we have to adapt the
* layout of our temporary area so as to include values for the registers
* that are to be restored, and later (in the implementation of KERNEL.621)
* we *really* restore them. The return stub restores DS, DI, SI, and BP
* from the stack, skips the next 8 bytes (CBClient relay code / target),
* and then performs a lret NN, where NN is the number of arguments to be
* removed. Thus, we prepare our temporary area as follows:
*
* (ebx+22) 16-bit cs (this segment)
* (ebx+20) 16-bit ip ('16-bit' return entry point)
* (ebx+16) 32-bit ss (flat)
* (ebx+12) 32-bit sp (32-bit stack pointer)
* (ebx+10) 16-bit bp (points to ebx+24)
* (ebx+8) 16-bit si (ignored)
* (ebx+6) 16-bit di (ignored)
* (ebx+4) 16-bit ds (we actually use the flat DS here)
* (ebx+2) 16-bit ss (16-bit stack segment)
* (ebx+0) 16-bit sp (points to ebx+4)
*
* Note that we ensure that DS is not changed and remains the flat segment,
* and the 32-bit stack pointer our own return stub needs fits just
* perfectly into the 8 bytes that are skipped by the Windows stub.
* One problem is that we have to determine the number of removed arguments,
* as these have to be really removed in KERNEL.621. Thus, the BP value
* that we place in the temporary area to be restored, contains the value
* that SP would have if no arguments were removed. By comparing the actual
* value of SP with this value in our return stub we can compute the number
* of removed arguments. This is then returned to KERNEL.621.
*
* The stack layout of this function:
* (ebp+20) nArgs pointer to variable receiving nr. of args (Ex only)
* (ebp+16) esi pointer to caller's esi value
* (ebp+12) arg ebp value to be set for relay stub
* (ebp+8) func CBClient relay stub address
* (ebp+4) ret addr
* (ebp) ebp
*/
static void BuildCallTo32CBClient( int isEx )
{
function_header( isEx ? "CALL32_CBClientEx" : "CALL32_CBClient" );
/* Entry code */
output_cfi( ".cfi_startproc" );
output( "\tpushl %%ebp\n" );
output_cfi( ".cfi_adjust_cfa_offset 4" );
output_cfi( ".cfi_rel_offset %%ebp,0" );
output( "\tmovl %%esp,%%ebp\n" );
output_cfi( ".cfi_def_cfa_register %%ebp" );
output( "\tpushl %%edi\n" );
output_cfi( ".cfi_rel_offset %%edi,-4" );
output( "\tpushl %%esi\n" );
output_cfi( ".cfi_rel_offset %%esi,-8" );
output( "\tpushl %%ebx\n" );
output_cfi( ".cfi_rel_offset %%ebx,-12" );
/* Get pointer to temporary area and save the 32-bit stack pointer */
output( "\tmovl 16(%%ebp), %%ebx\n" );
output( "\tleal -8(%%esp), %%eax\n" );
if ( !isEx )
output( "\tmovl %%eax, -8(%%ebx)\n" );
else
output( "\tmovl %%eax, 12(%%ebx)\n" );
/* Set up registers and call CBClient relay stub (simulating a far call) */
output( "\tmovl 20(%%ebp), %%esi\n" );
output( "\tmovl (%%esi), %%esi\n" );
output( "\tmovl 8(%%ebp), %%eax\n" );
output( "\tmovl 12(%%ebp), %%ebp\n" );
output( "\tpushl %%cs\n" );
output( "\tcall *%%eax\n" );
/* Return new esi value to caller */
output( "\tmovl 32(%%esp), %%edi\n" );
output( "\tmovl %%esi, (%%edi)\n" );
/* Return argument size to caller */
if ( isEx )
{
output( "\tmovl 36(%%esp), %%ebx\n" );
output( "\tmovl %%ebp, (%%ebx)\n" );
}
/* Restore registers and return */
output( "\tpopl %%ebx\n" );
output_cfi( ".cfi_same_value %%ebx" );
output( "\tpopl %%esi\n" );
output_cfi( ".cfi_same_value %%esi" );
output( "\tpopl %%edi\n" );
output_cfi( ".cfi_same_value %%edi" );
output( "\tpopl %%ebp\n" );
output_cfi( ".cfi_def_cfa %%esp,4" );
output_cfi( ".cfi_same_value %%ebp" );
output( "\tret\n" );
output_cfi( ".cfi_endproc" );
output_function_size( isEx ? "CALL32_CBClientEx" : "CALL32_CBClient" );
/* '16-bit' return stub */
function_header( isEx ? "CALL32_CBClientEx_Ret" : "CALL32_CBClient_Ret" );
if ( !isEx )
{
output( "\tmovzwl %%sp, %%ebx\n" );
output( "\tlssl %%ss:-16(%%ebx), %%esp\n" );
}
else
{
output( "\tmovzwl %%bp, %%ebx\n" );
output( "\tsubw %%bp, %%sp\n" );
output( "\tmovzwl %%sp, %%ebp\n" );
output( "\tlssl %%ss:-12(%%ebx), %%esp\n" );
}
output( "\tlret\n" );
output_function_size( isEx ? "CALL32_CBClientEx_Ret" : "CALL32_CBClient_Ret" );
}
/*******************************************************************
* output_asm_relays16
*
* Build all the 16-bit relay callbacks
*/
void output_asm_relays16(void)
{
/* File header */
output( "\t.text\n" );
output( "%s:\n\n", asm_name("__wine_spec_thunk_text_16") );
output( "%s\n", asm_globl("__wine_call16_start") );
/* Standard CallFrom16 routine */
BuildCallFrom16Core( 0, 0 );
/* Register CallFrom16 routine */
BuildCallFrom16Core( 1, 0 );
/* C16ThkSL CallFrom16 routine */
BuildCallFrom16Core( 0, 1 );
/* Standard CallTo16 routine */
BuildCallTo16Core( 0 );
/* Register CallTo16 routine */
BuildCallTo16Core( 1 );
/* Standard CallTo16 return stub */
BuildRet16Func();
/* CBClientThunkSL routine */
BuildCallTo32CBClient( 0 );
/* CBClientThunkSLEx routine */
BuildCallTo32CBClient( 1 );
output( "%s\n", asm_globl("__wine_call16_end") );
output_function_size( "__wine_spec_thunk_text_16" );
/* Declare the return address and data selector variables */
output( "\n\t.data\n\t.align %d\n", get_alignment(4) );
output( "%s\n\t.long 0\n", asm_globl("CallTo16_DataSelector") );
output( "%s\n\t.long 0\n", asm_globl("CallTo16_TebSelector") );
}