src/drivers/framebuffer/uefi.c

/*
 * Copyright 2016 Google Inc.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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; either version 2 of
 * the License, or (at your option) any later version.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <assert.h>

#include "base/algorithm.h"
#include "base/xalloc.h"
#include "drivers/framebuffer/framebuffer.h"
#include "drivers/framebuffer/uefi.h"
#include "uefi/edk/Protocol/GraphicsOutput.h"
#include "uefi/uefi.h"

static EFI_GUID uefi_graphics_output_guid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;

static int uefi_framebuffer_prepare(FrameBufferOps *me, FrameBuffer *buf)
{
	if (!framebuffer_read_from_fwdb(buf))
		return 0;

	EFI_SYSTEM_TABLE *st = uefi_system_table_ptr();
	assert(st);
	EFI_BOOT_SERVICES *bs = st->BootServices;

	UINTN buf_size = 0;
	EFI_HANDLE dummy_handle;
	EFI_STATUS status = bs->LocateHandle(
		ByProtocol, &uefi_graphics_output_guid, NULL,
		&buf_size, &dummy_handle);
	if (status == EFI_NOT_FOUND) {
		printf("No graphics output handles found.\n");
		return 1;
	}
	if (status != EFI_BUFFER_TOO_SMALL) {
		printf("Error retrieving graphics output protocol handles.\n");
		return 1;
	}

	EFI_HANDLE *handles = xmalloc(buf_size);

	status = bs->LocateHandle(
		ByProtocol, &uefi_graphics_output_guid, NULL,
		&buf_size, handles);
	if (status != EFI_SUCCESS) {
		printf("Failed to retrieve graphics output "
		       "protocol handles.\n");
		free(handles);
		return 1;
	}

	int handle_count = buf_size / sizeof(dummy_handle);
	if (handle_count > 1) {
		printf("Multiple graphics output devices found. Using the "
		       "first one.\n");
	}
	EFI_GRAPHICS_OUTPUT_PROTOCOL *gp;
	status = bs->HandleProtocol(
		handles[0], &uefi_graphics_output_guid, (void **)&gp);
	if (status != EFI_SUCCESS) {
		printf("Failed to extract graphics output protocol.\n");
		free(handles);
		return 1;
	}

	free(handles);


	buf->header.version = FrameBufferCurrentVersion;

	EFI_GRAPHICS_OUTPUT_PROTOCOL_MODE *mode = gp->Mode;
	buf->buffer = (void *)(uintptr_t)mode->FrameBufferBase;

	EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *info = mode->Info;
	buf->resolution.x = info->HorizontalResolution;
	buf->resolution.y = info->VerticalResolution;

	EFI_PIXEL_BITMASK *bm = &info->PixelInformation;
	switch (info->PixelFormat) {
	case PixelRedGreenBlueReserved8BitPerColor:
		buf->red.size = buf->green.size = buf->blue.size = 8;
		buf->red.pos = 0;
		buf->green.pos = 8;
		buf->blue.pos = 16;
		buf->bits_per_pixel = 32;
		break;
	case PixelBlueGreenRedReserved8BitPerColor:
		buf->red.size = buf->green.size = buf->blue.size = 8;
		buf->blue.pos = 0;
		buf->green.pos = 8;
		buf->red.pos = 16;
		buf->bits_per_pixel = 32;
		break;
	case PixelBitMask:
		buf->red.pos = CTZ(bm->RedMask);
		buf->red.size = CTZ(~bm->RedMask >> buf->red.pos);
		buf->green.pos = CTZ(bm->GreenMask);
		buf->green.size = CTZ(~bm->GreenMask >> buf->green.pos);
		buf->blue.pos = CTZ(bm->BlueMask);
		buf->blue.size = CTZ(~bm->BlueMask >> buf->blue.pos);
	case PixelBltOnly:
		printf("Physical framebuffer not supported.\n");
		return 1;
	default:
		printf("Unrecognized pixel format %d.\n", info->PixelFormat);
		return 1;
	}

	buf->bytes_per_line =
		((buf->bits_per_pixel + 7) / 8) * info->PixelsPerScanLine;

	return framebuffer_write_to_fwdb(buf);
}

FrameBufferOps *new_uefi_framebuffer(void)
{
	FrameBufferOps *fb = xzalloc(sizeof(*fb));
	fb->prepare = &uefi_framebuffer_prepare;
	return fb;
}