Pirkei Avos - Kol Yisroel

What is the origin of the practice of reciting the first piece of the first mishnah of Perek Cheilek prior to learning the week's chapter of Pirkei Avos?

The Rema miPano (cited at the beginning of Peirushei HaRishonim Al Avos) gives an interesting explanation of the practice's origins. The "last chapter" of Pirkei Avos, Perek Kinyan Torah, was appended to the 5 actual chapters of Maseches Avos in order that the resulting 6 chapters can be read on the 6 Shabbosos that fall out between Pesach and Shavu'os, being that the first Shabbos of sefirah always falls out during the chag, and thus does not receive a special chapter of learning.

When the first day of Pesach falls out on Shabbos, though, the first of the seven Shabbosos of sefirah falls out on Isru Chag in Eretz Yisroel, necessitating the addition of another section of learning for the extra Shabbos. The Rema miPano states that the practice developed in Eretz Yisroel in such situations to learn the gemara at the beginning of Perek Cheilek on Shabbos Isru Chag Pesach, based on the mesorah that t'chiyas ha-meisim, which is discussed in this sugya, will occur on Pesach (this is also the reason why we recite the haftarah of the dry bones from Yechezkel on Shabbos Chol HaMoed Pesach). Eventually, this practice evolved by several temporal and spatial degrees to the extent that the first piece of the mishnah is now read everywhere on every Shabbos before learning Pirkei Avos.