175f099b30
In write-only mode, writes are forwarded to RAM, while reads should not be handled (ie should return 0xff). Assume that in this mode, no read access is ever done, as they shouldn't give any sensible result. So, in write-only mode, alias PAM region to RAM, instead of PCI memory (which can even be mapped to some device!) This fixes Award BIOS, which use this mode to shadow system BIOS and video BIOS. Signed-off-by: Hervé Poussineau <hpoussin@reactos.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
90 lines
3.4 KiB
C
90 lines
3.4 KiB
C
/*
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* QEMU i440FX/PIIX3 PCI Bridge Emulation
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*
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* Copyright (c) 2006 Fabrice Bellard
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* Copyright (c) 2011 Isaku Yamahata <yamahata at valinux co jp>
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* VA Linux Systems Japan K.K.
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* Copyright (c) 2012 Jason Baron <jbaron@redhat.com>
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*
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* Split out from piix_pci.c
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qom/object.h"
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#include "sysemu/sysemu.h"
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#include "hw/pci-host/pam.h"
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void smram_update(MemoryRegion *smram_region, uint8_t smram,
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uint8_t smm_enabled)
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{
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bool smram_enabled;
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smram_enabled = ((smm_enabled && (smram & SMRAM_G_SMRAME)) ||
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(smram & SMRAM_D_OPEN));
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memory_region_set_enabled(smram_region, !smram_enabled);
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}
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void smram_set_smm(uint8_t *host_smm_enabled, int smm, uint8_t smram,
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MemoryRegion *smram_region)
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{
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uint8_t smm_enabled = (smm != 0);
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if (*host_smm_enabled != smm_enabled) {
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*host_smm_enabled = smm_enabled;
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smram_update(smram_region, smram, *host_smm_enabled);
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}
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}
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void init_pam(DeviceState *dev, MemoryRegion *ram_memory,
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MemoryRegion *system_memory, MemoryRegion *pci_address_space,
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PAMMemoryRegion *mem, uint32_t start, uint32_t size)
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{
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int i;
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/* RAM */
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memory_region_init_alias(&mem->alias[3], OBJECT(dev), "pam-ram", ram_memory,
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start, size);
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/* ROM (XXX: not quite correct) */
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memory_region_init_alias(&mem->alias[1], OBJECT(dev), "pam-rom", ram_memory,
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start, size);
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memory_region_set_readonly(&mem->alias[1], true);
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/* XXX: should distinguish read/write cases */
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memory_region_init_alias(&mem->alias[0], OBJECT(dev), "pam-pci", pci_address_space,
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start, size);
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memory_region_init_alias(&mem->alias[2], OBJECT(dev), "pam-pci", ram_memory,
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start, size);
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for (i = 0; i < 4; ++i) {
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memory_region_set_enabled(&mem->alias[i], false);
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memory_region_add_subregion_overlap(system_memory, start,
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&mem->alias[i], 1);
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}
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mem->current = 0;
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}
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void pam_update(PAMMemoryRegion *pam, int idx, uint8_t val)
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{
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assert(0 <= idx && idx <= 12);
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memory_region_set_enabled(&pam->alias[pam->current], false);
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pam->current = (val >> ((!(idx & 1)) * 4)) & PAM_ATTR_MASK;
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memory_region_set_enabled(&pam->alias[pam->current], true);
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}
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