diff options
Diffstat (limited to 'src/VBox/Devices/PC/BIOS/apm_pm.asm')
| -rw-r--r-- | src/VBox/Devices/PC/BIOS/apm_pm.asm | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/src/VBox/Devices/PC/BIOS/apm_pm.asm b/src/VBox/Devices/PC/BIOS/apm_pm.asm new file mode 100644 index 00000000..42c0baa0 --- /dev/null +++ b/src/VBox/Devices/PC/BIOS/apm_pm.asm @@ -0,0 +1,229 @@ +; $Id: +;; @file +; Protected-mode APM implementation. +; + +; +; Copyright (C) 2006-2023 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>. +; +; SPDX-License-Identifier: GPL-3.0-only +; + + +include commondefs.inc + +;; 16-bit protected mode APM entry point + +_TEXT segment public 'CODE' + +extern _apm_function:near ; implemented in C code + + +public apm_pm16_entry + +SET_DEFAULT_CPU_286 + + +; APM function dispatch table +apm_disp: + dw offset apmf_disconnect ; 04h + dw offset apmf_idle ; 05h + dw offset apmf_busy ; 06h + dw offset apmf_set_state ; 07h + dw offset apmf_enable ; 08h + dw offset apmf_restore ; 09h + dw offset apmf_get_status ; 0Ah + dw offset apmf_get_event ; 0Bh + dw offset apmf_pwr_state ; 0Ch + dw offset apmf_dev_pm ; 0Dh + dw offset apmf_version ; 0Eh + dw offset apmf_engage ; 0Fh + dw offset apmf_get_caps ; 10h +apm_disp_end: + +; +; APM worker routine. Function code in AL; it is assumed that AL >= 4. +; Caller must preserve BP. +; +apm_worker proc near + + sti ; TODO ?? necessary ?? + + push ax ; check if function is supported... + xor ah, ah + sub al, 4 + mov bp, ax + shl bp, 1 + cmp al, (apm_disp_end - apm_disp) / 2 + pop ax + mov ah, 53h ; put back APM function + jae apmw_bad_func ; validate function range + + jmp apm_disp[bp] ; and dispatch + +apmf_disconnect: ; function 04h + jmp apmw_success + +apmf_idle: ; function 05h + ; + ; Windows 3.1 POWER.DRV in Standard mode calls into APM + ; with CPL=3. If that happens, the HLT instruction will fault + ; and Windows will crash. To prevent that, we check the CPL + ; and do nothing (better than crashing). + ; + push cs + pop ax + test ax, 3 ; CPL > 0? + jnz apmw_success + sti + hlt + jmp apmw_success + +apmf_busy: ; function 06h +; jmp apmw_success + +apmf_set_state: ; function 07h +; jmp apmw_success + +apmf_enable: ; function 08h + jmp apmw_success + +apmf_restore: ; function 09h +; jmp apmw_success + +apmf_get_status: ; function 0Ah + jmp apmw_bad_func + +apmf_get_event: ; function 0Bh + mov ah, 80h + jmp apmw_failure + +apmf_pwr_state: ; function 0Ch + +apmf_dev_pm: ; function 0Dh + jmp apmw_bad_func + +apmf_version: ; function 0Eh + mov ax, 0102h + jmp apmw_success + +apmf_engage: ; function 0Fh + ; TODO do something? + jmp apmw_success + +apmf_get_caps: ; function 10h + mov bl, 0 ; no batteries + mov cx, 0 ; no special caps + jmp apmw_success + +apmw_success: + clc ; successful return + ret + +apmw_bad_func: + mov ah, 09h ; unrecognized device ID - generic + +apmw_failure: + stc ; error for unsupported functions + ret + +apm_worker endp + + +;; 16-bit protected mode APM entry point + +;; According to the APM spec, only CS (16-bit code selector) is defined. +;; The data selector can be derived from it. + +apm_pm16_entry: + + mov ah, 2 ; mark as originating in 16-bit PM + + ; fall through + +apm_pm16_entry_from_32: + + push ds ; save registers + push bp + + push cs + pop bp + add bp, 8 ; calculate data selector + mov ds, bp ; load data segment + + call apm_worker ; call APM handler + + pop bp + pop ds ; restore registers + + retf ; return to caller - 16-bit return + ; even to 32-bit thunk! + +_TEXT ends + + +if VBOX_BIOS_CPU ge 80386 + +.386 + +BIOS32 segment public 'CODE' use32 + +public apm_pm32_entry + +;; 32-bit protected mode APM entry point and thunk + +;; According to the APM spec, only CS (32-bit) is defined. 16-bit code +;; selector and the data selector can be derived from it. + +;; WARNING: To simplify matters, we use 16-bit far return to go from 32-bit +;; code to 16-bit and back. As a consequence, the 32-bit APM code must lie +;; below 64K boundary in the 32-bit APM code segment. + +apm_pm32_entry: + + push ebp ; ebp is not used by APM + + mov bp, cs ; return address for 16-bit code + push bp + mov ebp, apm_pm32_back + push bp ; Note: 16:16 address! + + push cs + pop ebp + add ebp, 8 ; calculate 16-bit code selector + push bp ; push 16-bit code selector + + mov ebp, apm_pm16_entry_from_32 + push bp ; push 16-bit offset + + mov ah, 3 ; mark as originating in 32-bit PM + + db 66h ; force a 16-bit return + retf ; off to 16-bit code... + +apm_pm32_back: ; return here from 16-bit code + + pop ebp ; restore scratch register + retf + +BIOS32 ends + +endif ; 32-bit code + + end |