1=============================================================== 2vt8623fb - fbdev driver for graphics core in VIA VT8623 chipset 3=============================================================== 4 5 6Supported Hardware 7================== 8 9VIA VT8623 [CLE266] chipset and its graphics core 10(known as CastleRock or Unichrome) 11 12I tested vt8623fb on VIA EPIA ML-6000 13 14 15Supported Features 16================== 17 18 * 4 bpp pseudocolor modes (with 18bit palette, two variants) 19 * 8 bpp pseudocolor mode (with 18bit palette) 20 * 16 bpp truecolor mode (RGB 565) 21 * 32 bpp truecolor mode (RGB 888) 22 * text mode (activated by bpp = 0) 23 * doublescan mode variant (not available in text mode) 24 * panning in both directions 25 * suspend/resume support 26 * DPMS support 27 28Text mode is supported even in higher resolutions, but there is limitation to 29lower pixclocks (maximum about 100 MHz). This limitation is not enforced by 30driver. Text mode supports 8bit wide fonts only (hardware limitation) and 3116bit tall fonts (driver limitation). 32 33There are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with 34packed pixels, high nibble first. Second mode (selected if nonstd == 1) is mode 35with interleaved planes (1 byte interleave), MSB first. Both modes support 368bit wide fonts only (driver limitation). 37 38Suspend/resume works on systems that initialize video card during resume and 39if device is active (for example used by fbcon). 40 41 42Missing Features 43================ 44(alias TODO list) 45 46 * secondary (not initialized by BIOS) device support 47 * MMIO support 48 * interlaced mode variant 49 * support for fontwidths != 8 in 4 bpp modes 50 * support for fontheight != 16 in text mode 51 * hardware cursor 52 * video overlay support 53 * vsync synchronization 54 * acceleration support (8514-like 2D, busmaster transfers) 55 56 57Known bugs 58========== 59 60 * cursor disable in text mode doesn't work 61 62 63-- 64Ondrej Zajicek <santiago@crfreenet.org> 65