3 files changed, 26 insertions, 0 deletions
diff --git a/Kernel/Graphics/Bochs/Definitions.h b/Kernel/Graphics/Bochs/Definitions.h
index 12ba53650a..1891b9f756 100644
--- a/Kernel/Graphics/Bochs/Definitions.h
+++ b/Kernel/Graphics/Bochs/Definitions.h
@@ -34,6 +34,7 @@ enum class BochsDISPIRegisters {
     VIRT_HEIGHT = 0x7,
     X_OFFSET = 0x8,
     Y_OFFSET = 0x9,
+    VIDEO_RAM_64K_CHUNKS_COUNT = 0xA,
 };
 
 struct [[gnu::packed]] DISPIInterface {
@@ -47,6 +48,7 @@ struct [[gnu::packed]] DISPIInterface {
     u16 virt_height;
     u16 x_offset;
     u16 y_offset;
+    u16 vram_64k_chunks_count;
 };
 
 struct [[gnu::packed]] ExtensionRegisters {
diff --git a/Kernel/Graphics/GraphicsManagement.cpp b/Kernel/Graphics/GraphicsManagement.cpp
index ef1f9ac195..6659b02b6f 100644
--- a/Kernel/Graphics/GraphicsManagement.cpp
+++ b/Kernel/Graphics/GraphicsManagement.cpp
@@ -7,6 +7,9 @@
 #include <AK/Singleton.h>
 #include <Kernel/Arch/Delay.h>
 #include <Kernel/Arch/x86/IO.h>
+#if ARCH(I386) || ARCH(X86_64)
+#    include <Kernel/Arch/x86/Hypervisor/BochsDisplayConnector.h>
+#endif
 #include <Kernel/Bus/PCI/API.h>
 #include <Kernel/Bus/PCI/IDs.h>
 #include <Kernel/CommandLine.h>
@@ -206,6 +209,25 @@ UNMAP_AFTER_INIT bool GraphicsManagement::initialize()
         return true;
     }
 
+    // Note: Don't try to initialize an ISA Bochs VGA adapter if PCI hardware is
+    // present but the user decided to disable its usage nevertheless.
+    // Otherwise we risk using the Bochs VBE driver on a wrong physical address
+    // for the framebuffer.
+    if (PCI::Access::is_hardware_disabled() && !(graphics_subsystem_mode == CommandLine::GraphicsSubsystemMode::Limited && !multiboot_framebuffer_addr.is_null() && multiboot_framebuffer_type == MULTIBOOT_FRAMEBUFFER_TYPE_RGB)) {
+#if ARCH(I386) || ARCH(X86_64)
+        auto vga_isa_bochs_display_connector = BochsDisplayConnector::try_create_for_vga_isa_connector();
+        if (vga_isa_bochs_display_connector) {
+            dmesgln("Graphics: Using a Bochs ISA VGA compatible adapter");
+            MUST(vga_isa_bochs_display_connector->set_safe_mode_setting());
+            m_platform_board_specific_display_connector = vga_isa_bochs_display_connector;
+            dmesgln("Graphics: Invoking manual blanking with VGA ISA ports");
+            SpinlockLocker locker(m_main_vga_lock);
+            IO::out8(0x3c0, 0x20);
+            return true;
+        }
+#endif
+    }
+
     if (graphics_subsystem_mode == CommandLine::GraphicsSubsystemMode::Limited && !multiboot_framebuffer_addr.is_null() && multiboot_framebuffer_type == MULTIBOOT_FRAMEBUFFER_TYPE_RGB) {
         initialize_preset_resolution_generic_display_connector();
         return true;
diff --git a/Kernel/Graphics/GraphicsManagement.h b/Kernel/Graphics/GraphicsManagement.h
index 28ffd32737..842c837d75 100644
--- a/Kernel/Graphics/GraphicsManagement.h
+++ b/Kernel/Graphics/GraphicsManagement.h
@@ -56,6 +56,8 @@ private:
     // Note: This is only used when booting with kernel commandline that includes "graphics_subsystem_mode=limited"
     LockRefPtr<GenericDisplayConnector> m_preset_resolution_generic_display_connector;
 
+    LockRefPtr<DisplayConnector> m_platform_board_specific_display_connector;
+
     unsigned m_current_minor_number { 0 };
 
     SpinlockProtected<IntrusiveList<&DisplayConnector::m_list_node>> m_display_connector_nodes { LockRank::None };