['softpipe', 'failover', 'svga', 'i915', 'i965', 'trace', 'r300', 'identity', 'llvmpipe']))
opts.Add(ListVariable('winsys', 'winsys drivers to build', default_winsys,
['xlib', 'vmware', 'intel', 'i965', 'gdi', 'radeon']))
['softpipe', 'failover', 'svga', 'i915', 'i965', 'trace', 'r300', 'identity', 'llvmpipe']))
opts.Add(ListVariable('winsys', 'winsys drivers to build', default_winsys,
['xlib', 'vmware', 'intel', 'i965', 'gdi', 'radeon']))