Kernel + WindowServer: Re-define the interface to framebuffer devices

We create a base class called GenericFramebufferDevice, which defines
all the virtual functions that must be implemented by a
FramebufferDevice. Then, we make the VirtIO FramebufferDevice and other
FramebufferDevice implementations inherit from it.
The most important consequence of rearranging the classes is that we now
have one IOCTL method, so all drivers should be committed to not
override the IOCTL method or make their own IOCTLs of FramebufferDevice.
All graphical IOCTLs are known to all FramebufferDevices, and it's up to
the specific implementation whether to support them or discard them (so
we require extensive usage of KResult and KResultOr, together with
virtual characteristic functions).
As a result, the interface is much cleaner and understandable to read.

1 files changed, 4 insertions, 4 deletions

diff --git a/Userland/DevTools/UserspaceEmulator/Emulator_syscalls.cpp b/Userland/DevTools/UserspaceEmulator/Emulator_syscalls.cpp
index 4fd60b2f2c..a3f65e10c0 100644
--- a/Userland/DevTools/UserspaceEmulator/Emulator_syscalls.cpp
+++ b/Userland/DevTools/UserspaceEmulator/Emulator_syscalls.cpp
@@ -1155,20 +1155,20 @@ int Emulator::virt$ioctl([[maybe_unused]] int fd, unsigned request, [[maybe_unus
     if (request == TIOCNOTTY || request == TIOCSCTTY) {
         return syscall(SC_ioctl, fd, request, 0);
     }
-    if (request == FB_IOCTL_GET_SIZE_IN_BYTES) {
+    if (request == FB_IOCTL_GET_PROPERTIES) {
         size_t size = 0;
         auto rc = syscall(SC_ioctl, fd, request, &size);
         mmu().copy_to_vm(arg, &size, sizeof(size));
         return rc;
     }
-    if (request == FB_IOCTL_SET_RESOLUTION) {
-        FBResolution user_resolution;
+    if (request == FB_IOCTL_SET_HEAD_RESOLUTION) {
+        FBHeadResolution user_resolution;
         mmu().copy_from_vm(&user_resolution, arg, sizeof(user_resolution));
         auto rc = syscall(SC_ioctl, fd, request, &user_resolution);
         mmu().copy_to_vm(arg, &user_resolution, sizeof(user_resolution));
         return rc;
     }
-    if (request == FB_IOCTL_SET_BUFFER) {
+    if (request == FB_IOCTL_SET_HEAD_VERTICAL_OFFSET_BUFFER) {
         return syscall(SC_ioctl, fd, request, arg);
     }
     reportln("Unsupported ioctl: {}", request);