Arunan from Cannada has given some very interesting links which predated badaga language to Kannada and equates it with Sangam or purana Tamil. Here is the link http://yabaluri.org/TRIVENI/CDWEB/TheTamilsandtheAndhras.htm
” Some of the Kanarese too seem to have been called Vadugar.7 In consequence of the Andhras and the Kanarese having been called by the common name of Vadugar in the days of the Sangam, it has been surmised that they were then one race and that their language too must have been known as Vadugu and that it is only later that Kanarese must have branched off into a separate language.8 But llam-Ko-Adigal, the great epic-poet of the Sangam age, mentions distinctly those who speak the Kanarese language as Karunadar,9 and other classical writers make mention separately of the lands where Kanarese and Telugu were respectively spoken.10 The northern portion of the Mysore state and parts of the districts of Bellary and Anantapur seem to be known even now as Badaga-nadu and the Kanarese of those areas are known as Badaga-varu and Badaga-natti-varu. A poem of the Sangam mentions an Erumai as a ‘Vadugar chief’ in whose land flowed the river Ayiri.11 This is evidently the Agiri which falls into the Tungabhadra. It is this country which was probably the extreme southern limit of the Asokan empire as is evidenced from inscriptions found in the vicinity.
If these be so, it follows that the Telugus who were to the north, and the Badaga Kannadas who were to the west, of the Tamils were known generically as the Vadugar. The poet, Ma-mulanar, says that it is beyond the lands of a chief of the name of Katti that the language changed into that of the Vadugar.12 Perhaps the chiefs well-known as Katti-Mudaliyars in the days of the Vijayanagar empire and later belonged to the lineage of this Katti.13 It is worthy of note that these Katti-Mudaliyars occupied those portions of the Tamil country which Ma-mulanar assigned to Katti. There are reasons to hold that the land called Vadugar-munai and placed beyond the lands of this Katti is identical with the Badaga-nadu we have already mentioned.14 It is these Badagas that seem to be referred to by St. Sundara in one of his psalms on a shrine in the Kongu country.15