af9bf8d721
ports stm32 ltdc and stm32 dma2d to framebuffer interface
* stm32: Removes current dma2d and ltdc implementation for replacement
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32f429i-disco: Removes obsolete functions call
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32_dma2d: Adds pixel format and transparency definitions
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32_dma2d: Adds interface definition
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32_dma2d: Reimplements dma2d driver
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32_ltdc: Adds interface definition
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32_ltdc: Reimplements ltdc driver
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32: Updates LTDC and DMA2D Kconfig definitions
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32f429i-disco: Fix compile error when ldc debug is enabled
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32f429i-disco: Adds helper script for frambuffer and heap2 calculation
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32f429i-disco: Update README for framebuffer configuration
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
* stm32f429i-disco: Update board configuration of framebuffer example
Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
113 lines
3.5 KiB
Plaintext
113 lines
3.5 KiB
Plaintext
README.txt
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==========
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STM32F429I-DISCO LTDC Framebuffer demo example
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Configure and build
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-------------------
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cd tools
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./configure -a <appdir> stm32f429i-disco/fb
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cd ..
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make
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Frambuffer calculation
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----------------------
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Use the helper script configs/stm32f429i-disco/tools/fbcalc.sh for calculating
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the heap2 and framebuffer memory region. The script assumes that all overlay
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buffers (LTDC and DMA2D) located in heap2 memory region starting at address
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0xD0000000. When changing the display size (when using a custom display), DMA2D
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overlay size or the pixel format you have to recalculate the heap2 settings.
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In this configuration all overlays (LTDC and DMA2D) positioned at the end of
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heap2.
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LTDC hardware acceleration
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--------------------------
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The LTDC driver provides two 2 LTDC overlays and supports the following hardware
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acceleration and features:
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Configured at build time
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- background color
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- default color (outside visible screen)
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Configurable by nuttx frambuffer interface
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- cmap support (color table is shared by both LTDC overlays and DMA2D when
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enabled)
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Configurable via the nuttx framebuffer interface (for each layer separately)
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- chromakey
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- transparency (const alpha and pixel alpha)
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- blank
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- color (if DMA2D is enabled and cmap is disabled)
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- blit (if DMA2D is enabled)
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- blend (if DMA2D is enabled and cmap is disabled)
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LTDC overlays are similar to a non-destructive overlay. Both LTDC overlays will
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be permanently blended in the order (background -> overlay 0 -> overlay 1) and
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converted to a resulting video signal by the LTDC controller. That means each
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operation with a LTDC overlay (Overlay 0 and Overlay 1) via nuttx framebuffer
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interface will be visible immediatelly.
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Think about continuous blending between both overlays.
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DMA2D hardware acceleration
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---------------------------
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The DMA2D driver implements the following hardware acceleration:
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Configurable via the nuttx framebuffer interface
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- cmap support (color table is shared by all DMA2D overlays and LTDC overlays)
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Configurable via the nuttx framebuffer interface (for each layer separately)
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- color (fill memory region with a specific ARGB8888 color immediatelly), if
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cmap is disabled
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- blit (copy memory region to another memory region with pixel format
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conversion if neccessary)
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- blend (blend two memory regions and copy the result to a third memory region
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with pixel format conversion if neccessary), if cmap is disabled
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Blit and blend operation using a fixes memory size defined by the background
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layer. DMA2D controller doesn't support scaling.
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DMA2D overlays are similar to destructive overlays. They are invisible. They can
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be used for image preprocessing. The memory region affected by the operations
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(color, blit, blend) can be addressed by the area control command before. The
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configured overlay transparency of DMA2D overlays will be used for subsequently
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blend operation and is valid for the whole overlay.
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Configuration
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------------
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This configuration provides 2 LTDC (visible overlays) and 2 DMA2D overlays with
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pixel format RGB565 and a resolution of 240x320.
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Loading
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-------
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st-flash write nuttx.bin 0x8000000
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Executing
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---------
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The ltdc is initialized during boot up. Interaction with NSH is via the serial
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console at 115200 8N1 baud. From the nsh comandline execute the fb example:
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nsh> fb
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The test will put a pattern of concentric squares in the framebuffer and
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terminate.
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You can also test overlay hardware acceleration functionality by executing the
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follwing command (shows a commandline help):
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nsh> fboverlay
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