1
2	s3fb - fbdev driver for S3 Trio/Virge chips
3	===========================================
4
5
6Supported Hardware
7==================
8
9	S3 Trio32
10	S3 Trio64 (and variants V+, UV+, V2/DX, V2/GX)
11	S3 Virge  (and variants VX, DX, GX and GX2+)
12	S3 Plato/PX		(completely untested)
13	S3 Aurora64V+		(completely untested)
14
15	- only PCI bus supported
16	- only BIOS initialized VGA devices supported
17	- probably not working on big endian
18
19I tested s3fb on Trio64 (plain, V+ and V2/DX) and Virge (plain, VX, DX),
20all on i386.
21
22
23Supported Features
24==================
25
26	*  4 bpp pseudocolor modes (with 18bit palette, two variants)
27	*  8 bpp pseudocolor mode (with 18bit palette)
28	* 16 bpp truecolor modes (RGB 555 and RGB 565)
29	* 24 bpp truecolor mode (RGB 888) on (only on Virge VX)
30	* 32 bpp truecolor mode (RGB 888) on (not on Virge VX)
31	* text mode (activated by bpp = 0)
32	* interlaced mode variant (not available in text mode)
33	* doublescan mode variant (not available in text mode)
34	* panning in both directions
35	* suspend/resume support
36	* DPMS support
37
38Text mode is supported even in higher resolutions, but there is limitation to
39lower pixclocks (maximum usually between 50-60 MHz, depending on specific
40hardware, i get best results from plain S3 Trio32 card - about 75 MHz). This
41limitation is not enforced by driver. Text mode supports 8bit wide fonts only
42(hardware limitation) and 16bit tall fonts (driver limitation). Text mode
43support is broken on S3 Trio64 V2/DX.
44
45There are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with
46packed pixels, high nibble first. Second mode (selected if nonstd == 1) is mode
47with interleaved planes (1 byte interleave), MSB first. Both modes support
488bit wide fonts only (driver limitation).
49
50Suspend/resume works on systems that initialize video card during resume and
51if device is active (for example used by fbcon).
52
53
54Missing Features
55================
56(alias TODO list)
57
58	* secondary (not initialized by BIOS) device support
59   	* big endian support
60	* Zorro bus support
61	* MMIO support
62	* 24 bpp mode support on more cards
63	* support for fontwidths != 8 in 4 bpp modes
64	* support for fontheight != 16 in text mode
65	* composite and external sync (is anyone able to test this?)
66	* hardware cursor
67	* video overlay support
68	* vsync synchronization
69	* feature connector support
70	* acceleration support (8514-like 2D, Virge 3D, busmaster transfers)
71	* better values for some magic registers (performance issues)
72
73
74Known bugs
75==========
76
77	* cursor disable in text mode doesn't work
78	* text mode broken on S3 Trio64 V2/DX
79
80
81--
82Ondrej Zajicek <santiago@crfreenet.org>
83