vt8623fb.rst 1.9 KB

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  1. ===============================================================
  2. vt8623fb - fbdev driver for graphics core in VIA VT8623 chipset
  3. ===============================================================
  4. Supported Hardware
  5. ==================
  6. VIA VT8623 [CLE266] chipset and its graphics core
  7. (known as CastleRock or Unichrome)
  8. I tested vt8623fb on VIA EPIA ML-6000
  9. Supported Features
  10. ==================
  11. * 4 bpp pseudocolor modes (with 18bit palette, two variants)
  12. * 8 bpp pseudocolor mode (with 18bit palette)
  13. * 16 bpp truecolor mode (RGB 565)
  14. * 32 bpp truecolor mode (RGB 888)
  15. * text mode (activated by bpp = 0)
  16. * doublescan mode variant (not available in text mode)
  17. * panning in both directions
  18. * suspend/resume support
  19. * DPMS support
  20. Text mode is supported even in higher resolutions, but there is limitation to
  21. lower pixclocks (maximum about 100 MHz). This limitation is not enforced by
  22. driver. Text mode supports 8bit wide fonts only (hardware limitation) and
  23. 16bit tall fonts (driver limitation).
  24. There are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with
  25. packed pixels, high nibble first. Second mode (selected if nonstd == 1) is mode
  26. with interleaved planes (1 byte interleave), MSB first. Both modes support
  27. 8bit wide fonts only (driver limitation).
  28. Suspend/resume works on systems that initialize video card during resume and
  29. if device is active (for example used by fbcon).
  30. Missing Features
  31. ================
  32. (alias TODO list)
  33. * secondary (not initialized by BIOS) device support
  34. * MMIO support
  35. * interlaced mode variant
  36. * support for fontwidths != 8 in 4 bpp modes
  37. * support for fontheight != 16 in text mode
  38. * hardware cursor
  39. * video overlay support
  40. * vsync synchronization
  41. * acceleration support (8514-like 2D, busmaster transfers)
  42. Known bugs
  43. ==========
  44. * cursor disable in text mode doesn't work
  45. --
  46. Ondrej Zajicek <santiago@crfreenet.org>