efi_loader: correctly support parameter delta in Blt
In the Blt service of the EFI_GRAPHICS_OUTPUT_PROTOCOL the parameter delta
is measured in bytes and not in pixels.
The coding only supports delta being a multiple of four. The UEFI
specification does not explicitly require this but as pixels have a size of
four bytes we should be able to assume four byte alignment.
The corresponding unit test is corrected, too. It can be launched with
setenv efi_selftest block image transfer
bootefi selftest
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_loader/efi_gop.c b/lib/efi_loader/efi_gop.c
index 154f306..ac92109 100644
--- a/lib/efi_loader/efi_gop.c
+++ b/lib/efi_loader/efi_gop.c
@@ -77,6 +77,24 @@
(u16)(blt->blue >> 3);
}
+/*
+ * 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
+ */
efi_status_t EFIAPI gop_blt(struct efi_gop *this, struct efi_gop_pixel *buffer,
u32 operation, efi_uintn_t sx,
efi_uintn_t sy, efi_uintn_t dx,
@@ -88,14 +106,18 @@
u32 *fb32 = gopobj->fb;
u16 *fb16 = gopobj->fb;
- if (delta)
- linelen = delta;
- else
- linelen = width;
-
EFI_ENTRY("%p, %p, %u, %zu, %zu, %zu, %zu, %zu, %zu, %zu", this,
buffer, operation, sx, sy, dx, dy, width, height, delta);
+ if (delta) {
+ /* Check for 4 byte alignment */
+ if (delta & 3)
+ return EFI_EXIT(EFI_INVALID_PARAMETER);
+ linelen = delta >> 2;
+ } else {
+ linelen = width;
+ }
+
/* Check source rectangle */
switch (operation) {
case EFI_BLT_VIDEO_FILL: