[PATCH v1 28/54] efi: loader: protocol: add graphical output protocol support

Ahmad Fatoum a.fatoum at pengutronix.de
Thu Dec 18 02:37:48 PST 2025


Add support for the graphical output protocol, so EFI applications can
draw to a barebox-provided framebuffer.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 efi/loader/protocols/Makefile |   1 +
 efi/loader/protocols/gop.c    | 572 ++++++++++++++++++++++++++++++++++
 include/efi/protocol/gop.h    |   9 +
 3 files changed, 582 insertions(+)
 create mode 100644 efi/loader/protocols/gop.c

diff --git a/efi/loader/protocols/Makefile b/efi/loader/protocols/Makefile
index 91bea23677e9..03095352d225 100644
--- a/efi/loader/protocols/Makefile
+++ b/efi/loader/protocols/Makefile
@@ -2,3 +2,4 @@
 
 obj-$(CONFIG_FS) += file.o
 obj-$(CONFIG_DISK) += disk.o
+obj-$(CONFIG_VIDEO) += gop.o
diff --git a/efi/loader/protocols/gop.c b/efi/loader/protocols/gop.c
new file mode 100644
index 000000000000..2d87acc9bcc7
--- /dev/null
+++ b/efi/loader/protocols/gop.c
@@ -0,0 +1,572 @@
+// SPDX-License-Identifier: GPL-2.0+
+// SPDX-Comment: Origin-URL: https://github.com/u-boot/u-boot/blob/459dbcb24837bb57750e854ad3ec6e49e11171ec/lib/efi_loader/efi_gop.c
+/*
+ *  EFI application disk support
+ *
+ *  Copyright (c) 2016 Alexander Graf
+ */
+
+#define pr_fmt(fmt) "efi-loader: gop: " fmt
+
+#include <efi/guid.h>
+#include <efi/loader.h>
+#include <efi/error.h>
+#include <efi/loader/object.h>
+#include <efi/loader/trace.h>
+#include <efi/protocol/gop.h>
+#include <malloc.h>
+#include <fb.h>
+#include <gui/graphic_utils.h>
+
+/**
+ * struct efi_gop_obj - graphical output protocol object
+ *
+ * @header:	EFI object header
+ * @ops:	graphical output protocol interface
+ * @info:	graphical output mode information
+ * @mode:	graphical output mode
+ * @fbi:	backing video device's framebuffer info
+ * @fb:		frame buffer
+ */
+struct efi_gop_obj {
+	struct efi_object header;
+	struct efi_graphics_output_protocol ops;
+	struct efi_graphics_output_mode_info info;
+	struct efi_graphics_output_protocol_mode mode;
+	struct fb_info *fbi;
+	/* Fields we only have access to during init */
+	void *fb;
+};
+
+static efi_status_t EFIAPI gop_query_mode(struct efi_graphics_output_protocol *this,
+					  u32 mode_number,
+					  efi_uintn_t *size_of_info,
+					  struct efi_graphics_output_mode_info **info)
+{
+	struct efi_gop_obj *gopobj;
+	efi_status_t ret = EFI_SUCCESS;
+
+	EFI_ENTRY("%p, %x, %p, %p", this, mode_number, size_of_info, info);
+
+	if (!this || !size_of_info || !info || mode_number) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+
+	gopobj = container_of(this, struct efi_gop_obj, ops);
+	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, sizeof(gopobj->info),
+				(void **)info, "gop");
+	if (ret != EFI_SUCCESS)
+		goto out;
+	*size_of_info = sizeof(gopobj->info);
+	memcpy(*info, &gopobj->info, sizeof(gopobj->info));
+
+out:
+	return EFI_EXIT(ret);
+}
+
+static __always_inline struct efi_pixel_bitmask efi_vid30_to_blt_col(u32 vid)
+{
+	struct efi_pixel_bitmask blt = {
+		.reserved_mask = 0,
+	};
+
+	blt.blue_mask  = (vid & 0x3ff) >> 2;
+	vid >>= 10;
+	blt.green_mask = (vid & 0x3ff) >> 2;
+	vid >>= 10;
+	blt.red_mask   = (vid & 0x3ff) >> 2;
+	return blt;
+}
+
+static __always_inline u32 efi_blt_col_to_vid30(struct efi_pixel_bitmask *blt)
+{
+	return (u32)(blt->red_mask   << 2) << 20 |
+	       (u32)(blt->green_mask << 2) << 10 |
+	       (u32)(blt->blue_mask  << 2);
+}
+
+static __always_inline struct efi_pixel_bitmask efi_vid16_to_blt_col(u16 vid)
+{
+	struct efi_pixel_bitmask blt = {
+		.reserved_mask = 0,
+	};
+
+	blt.blue_mask  = (vid & 0x1f) << 3;
+	vid >>= 5;
+	blt.green_mask = (vid & 0x3f) << 2;
+	vid >>= 6;
+	blt.red_mask   = (vid & 0x1f) << 3;
+	return blt;
+}
+
+static __always_inline u16 efi_blt_col_to_vid16(struct efi_pixel_bitmask *blt)
+{
+	return (u16)(blt->red_mask   >> 3) << 11 |
+	       (u16)(blt->green_mask >> 2) <<  5 |
+	       (u16)(blt->blue_mask  >> 3);
+}
+
+static __always_inline efi_status_t gop_blt_int(struct efi_graphics_output_protocol *this,
+						struct efi_pixel_bitmask *bufferp,
+						u32 operation, efi_uintn_t sx,
+						efi_uintn_t sy, efi_uintn_t dx,
+						efi_uintn_t dy,
+						efi_uintn_t width,
+						efi_uintn_t height,
+						efi_uintn_t delta,
+						efi_uintn_t vid_bpp)
+{
+	struct efi_gop_obj *gopobj = container_of(this, struct efi_gop_obj, ops);
+	efi_uintn_t i, j, linelen, slineoff = 0, dlineoff, swidth, dwidth;
+	u32 *fb32 = gopobj->fb;
+	u16 *fb16 = gopobj->fb;
+	struct efi_pixel_bitmask *buffer = __builtin_assume_aligned(bufferp, 4);
+	bool blt_to_video = (operation != EFI_BLT_VIDEO_TO_BLT_BUFFER);
+
+	if (delta) {
+		/* Check for 4 byte alignment */
+		if (delta & 3)
+			return EFI_INVALID_PARAMETER;
+		linelen = delta >> 2;
+	} else {
+		linelen = width;
+	}
+
+	/* Check source rectangle */
+	switch (operation) {
+	case EFI_BLT_VIDEO_FILL:
+		break;
+	case EFI_BLT_BUFFER_TO_VIDEO:
+		if (sx + width > linelen)
+			return EFI_INVALID_PARAMETER;
+		break;
+	case EFI_BLT_VIDEO_TO_BLT_BUFFER:
+	case EFI_BLT_VIDEO_TO_VIDEO:
+		if (sx + width > gopobj->info.horizontal_resolution ||
+		    sy + height > gopobj->info.vertical_resolution)
+			return EFI_INVALID_PARAMETER;
+		break;
+	default:
+		return EFI_INVALID_PARAMETER;
+	}
+
+	/* Check destination rectangle */
+	switch (operation) {
+	case EFI_BLT_VIDEO_FILL:
+	case EFI_BLT_BUFFER_TO_VIDEO:
+	case EFI_BLT_VIDEO_TO_VIDEO:
+		if (dx + width > gopobj->info.horizontal_resolution ||
+		    dy + height > gopobj->info.vertical_resolution)
+			return EFI_INVALID_PARAMETER;
+		break;
+	case EFI_BLT_VIDEO_TO_BLT_BUFFER:
+		if (dx + width > linelen)
+			return EFI_INVALID_PARAMETER;
+		break;
+	}
+
+	/* Calculate line width */
+	switch (operation) {
+	case EFI_BLT_BUFFER_TO_VIDEO:
+		swidth = linelen;
+		break;
+	case EFI_BLT_VIDEO_TO_BLT_BUFFER:
+	case EFI_BLT_VIDEO_TO_VIDEO:
+		swidth = gopobj->info.horizontal_resolution;
+		if (!vid_bpp)
+			return EFI_UNSUPPORTED;
+		break;
+	case EFI_BLT_VIDEO_FILL:
+		swidth = 0;
+		break;
+	}
+
+	switch (operation) {
+	case EFI_BLT_BUFFER_TO_VIDEO:
+	case EFI_BLT_VIDEO_FILL:
+	case EFI_BLT_VIDEO_TO_VIDEO:
+		dwidth = gopobj->info.horizontal_resolution;
+		if (!vid_bpp)
+			return EFI_UNSUPPORTED;
+		break;
+	case EFI_BLT_VIDEO_TO_BLT_BUFFER:
+		dwidth = linelen;
+		break;
+	}
+
+	slineoff = swidth * sy;
+	dlineoff = dwidth * dy;
+	for (i = 0; i < height; i++) {
+		for (j = 0; j < width; j++) {
+			struct efi_pixel_bitmask pix;
+
+			/* Read source pixel */
+			switch (operation) {
+			case EFI_BLT_VIDEO_FILL:
+				pix = *buffer;
+				break;
+			case EFI_BLT_BUFFER_TO_VIDEO:
+				pix = buffer[slineoff + j + sx];
+				break;
+			case EFI_BLT_VIDEO_TO_BLT_BUFFER:
+			case EFI_BLT_VIDEO_TO_VIDEO:
+				if (vid_bpp == 32)
+					pix = *(struct efi_pixel_bitmask *)&fb32[
+						slineoff + j + sx];
+				else if (vid_bpp == 30)
+					pix = efi_vid30_to_blt_col(fb32[
+						slineoff + j + sx]);
+				else
+					pix = efi_vid16_to_blt_col(fb16[
+						slineoff + j + sx]);
+				break;
+			}
+
+			/* Write destination pixel */
+			switch (operation) {
+			case EFI_BLT_VIDEO_TO_BLT_BUFFER:
+				buffer[dlineoff + j + dx] = pix;
+				break;
+			case EFI_BLT_BUFFER_TO_VIDEO:
+			case EFI_BLT_VIDEO_FILL:
+			case EFI_BLT_VIDEO_TO_VIDEO:
+				if (vid_bpp == 32)
+					fb32[dlineoff + j + dx] = *(u32 *)&pix;
+				else if (vid_bpp == 30)
+					fb32[dlineoff + j + dx] =
+						efi_blt_col_to_vid30(&pix);
+				else
+					fb16[dlineoff + j + dx] =
+						efi_blt_col_to_vid16(&pix);
+				break;
+			}
+		}
+		slineoff += swidth;
+		dlineoff += dwidth;
+	}
+
+	if (blt_to_video) {
+		struct fb_rect rect = { dx, dy, width, height };
+		fb_damage(gopobj->fbi, &rect);
+	}
+
+	return EFI_SUCCESS;
+}
+
+static efi_uintn_t gop_get_bpp(struct efi_graphics_output_protocol *this)
+{
+	struct efi_gop_obj *gopobj = container_of(this, struct efi_gop_obj, ops);
+	efi_uintn_t vid_bpp = 0;
+
+	switch (gopobj->fbi->bits_per_pixel) {
+	case 32:
+		if (gopobj->info.pixel_format == EFI_GOT_BGRA8)
+			vid_bpp = 32;
+		else
+			vid_bpp = 30;
+		break;
+	case 16:
+		vid_bpp = 16;
+		break;
+	}
+
+	return vid_bpp;
+}
+
+/*
+ * GCC can't optimize our BLT function well, but we need to make sure that
+ * our 2-dimensional loop gets executed very quickly, otherwise the system
+ * will feel slow.
+ *
+ * By manually putting all obvious branch targets into functions which call
+ * our generic BLT function with constants, the compiler can successfully
+ * optimize for speed.
+ */
+static efi_status_t gop_blt_video_fill(struct efi_graphics_output_protocol *this,
+				       struct efi_pixel_bitmask *buffer,
+				       u32 foo, efi_uintn_t sx,
+				       efi_uintn_t sy, efi_uintn_t dx,
+				       efi_uintn_t dy, efi_uintn_t width,
+				       efi_uintn_t height, efi_uintn_t delta,
+				       efi_uintn_t vid_bpp)
+{
+	return gop_blt_int(this, buffer, EFI_BLT_VIDEO_FILL, sx, sy, dx,
+			   dy, width, height, delta, vid_bpp);
+}
+
+static efi_status_t gop_blt_buf_to_vid16(struct efi_graphics_output_protocol *this,
+					 struct efi_pixel_bitmask *buffer,
+					 u32 foo, efi_uintn_t sx,
+					 efi_uintn_t sy, efi_uintn_t dx,
+					 efi_uintn_t dy, efi_uintn_t width,
+					 efi_uintn_t height, efi_uintn_t delta)
+{
+	return gop_blt_int(this, buffer, EFI_BLT_BUFFER_TO_VIDEO, sx, sy, dx,
+			   dy, width, height, delta, 16);
+}
+
+static efi_status_t gop_blt_buf_to_vid30(struct efi_graphics_output_protocol *this,
+					 struct efi_pixel_bitmask *buffer,
+					 u32 foo, efi_uintn_t sx,
+					 efi_uintn_t sy, efi_uintn_t dx,
+					 efi_uintn_t dy, efi_uintn_t width,
+					 efi_uintn_t height, efi_uintn_t delta)
+{
+	return gop_blt_int(this, buffer, EFI_BLT_BUFFER_TO_VIDEO, sx, sy, dx,
+			   dy, width, height, delta, 30);
+}
+
+static efi_status_t gop_blt_buf_to_vid32(struct efi_graphics_output_protocol *this,
+					 struct efi_pixel_bitmask *buffer,
+					 u32 foo, efi_uintn_t sx,
+					 efi_uintn_t sy, efi_uintn_t dx,
+					 efi_uintn_t dy, efi_uintn_t width,
+					 efi_uintn_t height, efi_uintn_t delta)
+{
+	return gop_blt_int(this, buffer, EFI_BLT_BUFFER_TO_VIDEO, sx, sy, dx,
+			   dy, width, height, delta, 32);
+}
+
+static efi_status_t gop_blt_vid_to_vid(struct efi_graphics_output_protocol *this,
+				       struct efi_pixel_bitmask *buffer,
+				       u32 foo, efi_uintn_t sx,
+				       efi_uintn_t sy, efi_uintn_t dx,
+				       efi_uintn_t dy, efi_uintn_t width,
+				       efi_uintn_t height, efi_uintn_t delta,
+				       efi_uintn_t vid_bpp)
+{
+	return gop_blt_int(this, buffer, EFI_BLT_VIDEO_TO_VIDEO, sx, sy, dx,
+			   dy, width, height, delta, vid_bpp);
+}
+
+static efi_status_t gop_blt_vid_to_buf(struct efi_graphics_output_protocol *this,
+				       struct efi_pixel_bitmask *buffer,
+				       u32 foo, efi_uintn_t sx,
+				       efi_uintn_t sy, efi_uintn_t dx,
+				       efi_uintn_t dy, efi_uintn_t width,
+				       efi_uintn_t height, efi_uintn_t delta,
+				       efi_uintn_t vid_bpp)
+{
+	return gop_blt_int(this, buffer, EFI_BLT_VIDEO_TO_BLT_BUFFER, sx, sy,
+			   dx, dy, width, height, delta, vid_bpp);
+}
+
+/**
+ * gop_set_mode() - set graphical output mode
+ *
+ * This function implements the SetMode() service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @this:		the graphical output protocol
+ * @mode_number:	the mode to be set
+ * Return:		status code
+ */
+static efi_status_t EFIAPI gop_set_mode(struct efi_graphics_output_protocol *this,
+					u32 mode_number)
+{
+	struct efi_gop_obj *gopobj;
+	struct efi_pixel_bitmask buffer = {0, 0, 0, 0};
+	efi_uintn_t vid_bpp;
+	efi_status_t ret = EFI_SUCCESS;
+
+	EFI_ENTRY("%p, %x", this, mode_number);
+
+	if (!this) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+	if (mode_number) {
+		ret = EFI_UNSUPPORTED;
+		goto out;
+	}
+	gopobj = container_of(this, struct efi_gop_obj, ops);
+	vid_bpp = gop_get_bpp(this);
+	ret = gop_blt_video_fill(this, &buffer, EFI_BLT_VIDEO_FILL, 0, 0, 0, 0,
+				 gopobj->info.horizontal_resolution,
+				 gopobj->info.vertical_resolution, 0,
+				 vid_bpp);
+out:
+	return EFI_EXIT(ret);
+}
+
+/*
+ * Copy rectangle.
+ *
+ * This function implements the Blt service of the EFI_GRAPHICS_OUTPUT_PROTOCOL.
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @this:	EFI_GRAPHICS_OUTPUT_PROTOCOL
+ * @buffer:	pixel buffer
+ * @sx:		source x-coordinate
+ * @sy:		source y-coordinate
+ * @dx:		destination x-coordinate
+ * @dy:		destination y-coordinate
+ * @width:	width of rectangle
+ * @height:	height of rectangle
+ * @delta:	length in bytes of a line in the pixel buffer (optional)
+ * Return:	status code
+ */
+static efi_status_t EFIAPI gop_blt(struct efi_graphics_output_protocol *this,
+				   struct efi_pixel_bitmask *buffer,
+				   u32 operation, efi_uintn_t sx,
+				   efi_uintn_t sy, efi_uintn_t dx,
+				   efi_uintn_t dy, efi_uintn_t width,
+				   efi_uintn_t height, efi_uintn_t delta)
+{
+	efi_status_t ret = EFI_INVALID_PARAMETER;
+	struct efi_gop_obj *gopobj = container_of(this, struct efi_gop_obj, ops);
+	efi_uintn_t vid_bpp;
+
+	EFI_ENTRY("%p, %p, %u, %zu, %zu, %zu, %zu, %zu, %zu, %zu", this,
+		  buffer, operation, sx, sy, dx, dy, width, height, delta);
+
+	vid_bpp = gop_get_bpp(this);
+
+	/* Allow for compiler optimization */
+	switch (operation) {
+	case EFI_BLT_VIDEO_FILL:
+		ret = gop_blt_video_fill(this, buffer, operation, sx, sy, dx,
+					 dy, width, height, delta, vid_bpp);
+		break;
+	case EFI_BLT_BUFFER_TO_VIDEO:
+		/* This needs to be super-fast, so duplicate for 16/32bpp */
+		if (vid_bpp == 32)
+			ret = gop_blt_buf_to_vid32(this, buffer, operation, sx,
+						   sy, dx, dy, width, height,
+						   delta);
+		else if (vid_bpp == 30)
+			ret = gop_blt_buf_to_vid30(this, buffer, operation, sx,
+						   sy, dx, dy, width, height,
+						   delta);
+		else
+			ret = gop_blt_buf_to_vid16(this, buffer, operation, sx,
+						   sy, dx, dy, width, height,
+						   delta);
+		break;
+	case EFI_BLT_VIDEO_TO_VIDEO:
+		ret = gop_blt_vid_to_vid(this, buffer, operation, sx, sy, dx,
+					 dy, width, height, delta, vid_bpp);
+		break;
+	case EFI_BLT_VIDEO_TO_BLT_BUFFER:
+		ret = gop_blt_vid_to_buf(this, buffer, operation, sx, sy, dx,
+					 dy, width, height, delta, vid_bpp);
+		break;
+	default:
+		ret = EFI_INVALID_PARAMETER;
+	}
+
+	if (ret != EFI_SUCCESS)
+		return EFI_EXIT(ret);
+
+	fb_flush(gopobj->fbi);
+
+	return EFI_EXIT(EFI_SUCCESS);
+}
+
+static bool format_is_x2r10g10b10(struct fb_info *fbi)
+{
+	return fbi->red.length == 10 && fbi->green.length == 10 &&
+		fbi->blue.length == 10;
+}
+
+static char *fbdev = "/dev/fb0";
+
+/*
+ * Install graphical output protocol if possible.
+ */
+static efi_status_t efi_gop_register(void *data)
+{
+	struct efi_gop_obj *gopobj;
+	u32 col, row;
+	efi_status_t ret;
+	struct fb_info *fbi;
+	struct screen *sc;
+	struct efi_pixel_bitmask *pixel_information;
+
+	sc = fb_open(fbdev);
+	if (IS_ERR(sc)) {
+		pr_debug("fb_open: %pe\n", sc);
+		return EFI_UNSUPPORTED;
+	}
+
+	fbi = sc->info;
+	col = fbi->xres;
+	row = fbi->yres;
+
+	switch (fbi->bits_per_pixel) {
+	case 16:
+	case 32:
+		break;
+	default:
+		/* So far, we only work in 16 or 32 bit mode */
+		pr_err("Unsupported video mode\n");
+		return EFI_UNSUPPORTED;
+	}
+
+	gopobj = calloc(1, sizeof(*gopobj));
+	if (!gopobj) {
+		pr_err("Out of memory\n");
+		return EFI_OUT_OF_RESOURCES;
+	}
+
+	/* Hook up to the device list */
+	efi_add_handle(&gopobj->header);
+
+	/* Fill in object data */
+	ret = efi_add_protocol(&gopobj->header, &efi_gop_guid,
+			       &gopobj->ops);
+	if (ret != EFI_SUCCESS) {
+		pr_err("Failure adding GOP protocol\n");
+		return ret;
+	}
+	gopobj->ops.query_mode = gop_query_mode;
+	gopobj->ops.set_mode = gop_set_mode;
+	gopobj->ops.blt = gop_blt;
+	gopobj->ops.mode = &gopobj->mode;
+
+	gopobj->mode.max_mode = 1;
+	gopobj->mode.info = &gopobj->info;
+	gopobj->mode.size_of_info = sizeof(gopobj->info);
+
+	gopobj->mode.frame_buffer_base = fbi->screen_base;
+	gopobj->mode.frame_buffer_size = fbi->line_length * fbi->yres;
+
+	gopobj->info.version = 0;
+	gopobj->info.horizontal_resolution = col;
+	gopobj->info.vertical_resolution = row;
+
+	pixel_information = &gopobj->info.pixel_information;
+
+	if (fbi->bits_per_pixel == 32) {
+		if (format_is_x2r10g10b10(fbi)) {
+			gopobj->info.pixel_format = EFI_GOT_BITMASK;
+			pixel_information->red_mask = 0x3ff00000;
+			pixel_information->green_mask = 0x000ffc00;
+			pixel_information->blue_mask = 0x000003ff;
+			pixel_information->reserved_mask = 0xc0000000;
+		} else {
+			gopobj->info.pixel_format = EFI_GOT_BGRA8;
+		}
+	} else {
+		gopobj->info.pixel_format = EFI_GOT_BITMASK;
+		pixel_information->red_mask = 0xf800;
+		pixel_information->green_mask = 0x07e0;
+		pixel_information->blue_mask = 0x001f;
+	}
+	gopobj->info.pixels_per_scan_line = col;
+	gopobj->fb = fb_get_screen_base(fbi);
+	gopobj->fbi = fbi;
+
+	return EFI_SUCCESS;
+}
+
+static int efi_gop_init(void)
+{
+	efi_register_deferred_init(efi_gop_register, NULL);
+	return 0;
+}
+device_initcall(efi_gop_init);
diff --git a/include/efi/protocol/gop.h b/include/efi/protocol/gop.h
index 04d139ffcb3f..12a5ea6d0fe0 100644
--- a/include/efi/protocol/gop.h
+++ b/include/efi/protocol/gop.h
@@ -10,6 +10,10 @@
 #define PIXEL_BLT_ONLY					3
 #define PIXEL_FORMAT_MAX				4
 
+#define EFI_GOT_RGBA8		0
+#define EFI_GOT_BGRA8		1
+#define EFI_GOT_BITMASK		2
+
 struct efi_pixel_bitmask {
 	u32 red_mask;
 	u32 green_mask;
@@ -17,6 +21,11 @@ struct efi_pixel_bitmask {
 	u32 reserved_mask;
 };
 
+#define EFI_BLT_VIDEO_FILL		0
+#define EFI_BLT_VIDEO_TO_BLT_BUFFER	1
+#define EFI_BLT_BUFFER_TO_VIDEO		2
+#define EFI_BLT_VIDEO_TO_VIDEO		3
+
 struct efi_graphics_output_mode_info {
 	u32 version;
 	u32 horizontal_resolution;
-- 
2.47.3




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