d04b388381
For payloads with UI based on CBGFX, they usually start by calling
clear_canvas or clear_screen and then draw the UI elements. However,
that makes the screen flicker.
A typical solution is to identify and minimize the area to redraw.
However for payloads with complicated UI and do not care about latency,
an alternative is to enable buffered I/O.
The new enable_graphics_buffer() will redirect all graphics I/O
into an invisible working buffer. To flush (redraw) the buffer to the
real screen, call flush_graphics_buffer(). To stop buffering, call
disable_graphics_buffer().
BUG=None
TEST=Add the enable, flush and disable calls to payload 'depthcharge',
built a firmware and boots into Chrome OS recover UI. No more
flickering. The average rendering time on x86 platform is 1.2ms.
Change-Id: Id60a2824fd9e164feae16b92b68b003beabea8d3
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44654
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
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| .. | ||
| arm/arch | ||
| arm64/arch | ||
| arpa | ||
| pci | ||
| storage | ||
| sys | ||
| udc | ||
| usb | ||
| x86/arch | ||
| archive.h | ||
| assert.h | ||
| cbfs.h | ||
| cbfs_core.h | ||
| cbfs_ram.h | ||
| cbgfx.h | ||
| compiler.h | ||
| coreboot_tables.h | ||
| ctype.h | ||
| die.h | ||
| endian.h | ||
| errno.h | ||
| exception.h | ||
| fmap_serialized.h | ||
| fpmath.h | ||
| gdb.h | ||
| getopt.h | ||
| inttypes.h | ||
| ipchksum.h | ||
| kconfig.h | ||
| keycodes.h | ||
| libpayload.h | ||
| limits.h | ||
| lz4.h | ||
| lzma.h | ||
| malloc.h | ||
| multiboot_tables.h | ||
| panel.h | ||
| pci.h | ||
| queue.h | ||
| stdarg.h | ||
| stddef.h | ||
| stdint.h | ||
| stdio.h | ||
| stdlib.h | ||
| string.h | ||
| strings.h | ||
| sysinfo.h | ||
| term.h | ||
| time.h | ||
| unistd.h | ||
| video_console.h | ||