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