ladybird/Kernel/Graphics/Bochs/GraphicsAdapter.cpp
Liav A e2ed6ef741 Kernel/Graphics: Bring back the mmap interface for DisplayConnectors
The mmap interface was removed when we introduced the DisplayConnector
class, as it was quite unsafe to use and didn't handle switching between
graphical and text modes safely. By using the SharedFramebufferVMObject,
we are able to elegantly coordinate the switch by remapping the attached
mmap'ed-Memory::Region(s) with different mappings, therefore, keeping
WindowServer to think that the mappings it has are still valid, while
they are going to a different physical range until we are back to the
graphical mode (after a switch from text mode).

Most drivers take advantage of the fact that we know where is the actual
framebuffer in physical memory space, the SharedFramebufferVMObject is
created with that information. However, the VirtIO driver is different
in that aspect, because it relies on DMA transactions to show graphics
on the framebuffer, so the SharedFramebufferVMObject is created with
that mindset to support the arbitrary framebuffer location in physical
memory space.
2022-06-06 20:11:05 +01:00

75 lines
3.3 KiB
C++

/*
* Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Atomic.h>
#include <AK/Checked.h>
#include <AK/Try.h>
#include <Kernel/Arch/x86/IO.h>
#include <Kernel/Bus/PCI/API.h>
#include <Kernel/Bus/PCI/IDs.h>
#include <Kernel/Debug.h>
#include <Kernel/Graphics/Bochs/Definitions.h>
#include <Kernel/Graphics/Bochs/DisplayConnector.h>
#include <Kernel/Graphics/Bochs/GraphicsAdapter.h>
#include <Kernel/Graphics/Bochs/QEMUDisplayConnector.h>
#include <Kernel/Graphics/Console/ContiguousFramebufferConsole.h>
#include <Kernel/Graphics/GraphicsManagement.h>
#include <Kernel/Memory/TypedMapping.h>
#include <Kernel/Sections.h>
namespace Kernel {
UNMAP_AFTER_INIT NonnullRefPtr<BochsGraphicsAdapter> BochsGraphicsAdapter::initialize(PCI::DeviceIdentifier const& pci_device_identifier)
{
PCI::HardwareID id = pci_device_identifier.hardware_id();
VERIFY((id.vendor_id == PCI::VendorID::QEMUOld && id.device_id == 0x1111) || (id.vendor_id == PCI::VendorID::VirtualBox && id.device_id == 0xbeef));
auto adapter = adopt_ref(*new BochsGraphicsAdapter(pci_device_identifier));
MUST(adapter->initialize_adapter(pci_device_identifier));
return adapter;
}
UNMAP_AFTER_INIT BochsGraphicsAdapter::BochsGraphicsAdapter(PCI::DeviceIdentifier const& pci_device_identifier)
: PCI::Device(pci_device_identifier.address())
{
if (pci_device_identifier.class_code().value() == 0x3 && pci_device_identifier.subclass_code().value() == 0x0)
m_is_vga_capable = true;
}
UNMAP_AFTER_INIT ErrorOr<void> BochsGraphicsAdapter::initialize_adapter(PCI::DeviceIdentifier const& pci_device_identifier)
{
// Note: If we use VirtualBox graphics adapter (which is based on Bochs one), we need to use IO ports
// Note: Bochs (the real bochs graphics adapter in the Bochs emulator) uses revision ID of 0x0
// and doesn't support memory-mapped IO registers.
auto bar0_space_size = PCI::get_BAR_space_size(pci_device_identifier.address(), 0);
if (pci_device_identifier.revision_id().value() == 0x0
|| (pci_device_identifier.hardware_id().vendor_id == 0x80ee && pci_device_identifier.hardware_id().device_id == 0xbeef)) {
m_display_connector = BochsDisplayConnector::must_create(PhysicalAddress(PCI::get_BAR0(pci_device_identifier.address()) & 0xfffffff0), bar0_space_size);
} else {
auto registers_mapping = TRY(Memory::map_typed_writable<BochsDisplayMMIORegisters volatile>(PhysicalAddress(PCI::get_BAR2(pci_device_identifier.address()) & 0xfffffff0)));
VERIFY(registers_mapping.region);
m_display_connector = QEMUDisplayConnector::must_create(PhysicalAddress(PCI::get_BAR0(pci_device_identifier.address()) & 0xfffffff0), bar0_space_size, move(registers_mapping));
}
// Note: According to Gerd Hoffmann - "The linux driver simply does
// the unblank unconditionally. With bochs-display this is not needed but
// it also has no bad side effect".
// FIXME: If the error is ENOTIMPL, ignore it for now until we implement
// unblank support for VBoxDisplayConnector class too.
auto result = m_display_connector->unblank();
if (result.is_error() && result.error().code() != ENOTIMPL)
return result;
TRY(m_display_connector->set_safe_mode_setting());
return {};
}
bool BochsGraphicsAdapter::vga_compatible() const
{
return m_is_vga_capable;
}
}