MMC/eMMC Boot sequence
CMD 1 is supposed to have the OCR Code with out the busy bit as the 32bit payload. You should be sending 

cmd &lt;="01" &amp; "000001" &amp; x"80FF8080" &amp; "0010110" &amp; '1'; 

according to section A.6.1 for chips with capacity less than or equal to 2GB and 

cmd &lt;="01" &amp; "000001" &amp; x"C0FF8080" &amp; "1011111" &amp; '1'; 

for chips greater than 2GB.