diff options
Diffstat (limited to 'src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatDataToProtFar16.asm')
| -rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatDataToProtFar16.asm | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatDataToProtFar16.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatDataToProtFar16.asm new file mode 100644 index 00000000..163b9b43 --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatDataToProtFar16.asm @@ -0,0 +1,142 @@ +; $Id: bs3-cmn-SelFlatDataToProtFar16.asm $ +;; @file +; BS3Kit - Bs3SelFlatDataToProtFar16. +; + +; +; Copyright (C) 2007-2022 Oracle and/or its affiliates. +; +; This file is part of VirtualBox base platform packages, as +; available from https://www.virtualbox.org. +; +; This program is free software; you can redistribute it and/or +; modify it under the terms of the GNU General Public License +; as published by the Free Software Foundation, in version 3 of the +; License. +; +; This program 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 +; General Public License for more details. +; +; You should have received a copy of the GNU General Public License +; along with this program; if not, see <https://www.gnu.org/licenses>. +; +; The contents of this file may alternatively be used under the terms +; of the Common Development and Distribution License Version 1.0 +; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included +; in the VirtualBox distribution, in which case the provisions of the +; CDDL are applicable instead of those of the GPL. +; +; You may elect to license modified versions of this file under the +; terms and conditions of either the GPL or the CDDL or both. +; +; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 +; + + +;********************************************************************************************************************************* +;* Header Files * +;********************************************************************************************************************************* +%include "bs3kit-template-header.mac" + + +;********************************************************************************************************************************* +;* External Symbols * +;********************************************************************************************************************************* +%ifdef BS3_STRICT +BS3_EXTERN_CMN Bs3Panic +%endif + +TMPL_BEGIN_TEXT +%if TMPL_BITS == 16 +CPU 8086 +%endif + + +;; +; @cproto BS3_CMN_PROTO_NOSB(uint32_t, Bs3SelFlatDataToProtFar16,(uint32_t uFlatAddr)); +; +; @uses Only return registers (ax:dx, eax, eax) +; @remarks No 20h scratch area requirements. +; +BS3_PROC_BEGIN_CMN Bs3SelFlatDataToProtFar16, BS3_PBC_NEAR ; Far stub generated by the makefile/bs3kit.h. + push xBP + mov xBP, xSP + + ; + ; Check if we can use the protected mode stack or data selector. + ; The latter ensures the usability of this function for setting SS. + ; +%if TMPL_BITS == 16 + mov ax, [xBP + xCB + cbCurRetAddr] + mov dx, [xBP + xCB + cbCurRetAddr + 2] + test dx, dx + jnz .not_stack + mov dx, BS3_SEL_R0_SS16 +%else +TNOT64 mov eax, [xBP + xCB + cbCurRetAddr] +TONLY64 mov eax, ecx + test eax, 0ffff0000h + jnz .not_stack + or eax, BS3_SEL_R0_SS16 << 16 +%endif + jmp .return + +.not_stack: +%if TMPL_BITS == 16 + sub ax, BS3_ADDR_BS3DATA16 & 0xffff + sbb dx, BS3_ADDR_BS3DATA16 >> 16 + jnz .do_tiled + mov dx, BS3_SEL_R0_DS16 +%else + sub eax, BS3_ADDR_BS3DATA16 + test eax, 0ffff0000h + jnz .do_tiled + or eax, BS3_SEL_R0_DS16 << 16 +%endif + jmp .return + + ; + ; Just translate the address to tiled. + ; +.do_tiled: +%if TMPL_BITS == 16 + ; Convert upper 16-bit to a tiled selector. + mov ax, cx ; save cx + mov dx, [xBP + xCB + cbCurRetAddr + 2] + %ifdef BS3_STRICT + cmp dx, BS3_SEL_TILED_AREA_SIZE >> 16 + jb .address_ok + call Bs3Panic +.address_ok: + %endif + mov cl, X86_SEL_SHIFT + shl dx, cl + add dx, BS3_SEL_TILED + mov cx, ax ; restore cx + + ; Load segment offset and return. + mov ax, [xBP + xCB + cbCurRetAddr] + +%else + ; Convert upper 16-bit to tiled selector. +TNOT64 mov eax, [xBP + xCB + cbCurRetAddr] +TONLY64 mov rax, rcx + %ifdef BS3_STRICT + cmp xAX, BS3_SEL_TILED_AREA_SIZE + jb .address_ok + call Bs3Panic +.address_ok: + %endif + ror eax, 16 + shl ax, X86_SEL_SHIFT + add ax, BS3_SEL_TILED + rol eax, 16 +%endif + +.return: + pop xBP + BS3_HYBRID_RET +BS3_PROC_END_CMN Bs3SelFlatDataToProtFar16 + |