microSD Class 4 card in SPI mode returns 0x000000021F after `CMD8`
Attached CMD8 picture shows normal response 1AA (2.7 - 3.6 V, and check pattern AA).

Several notes on things I see:


do not start command immediately after you activate CS. Wait 8 spare clock cycles, and only then start the command;
same at the end. Do not deactivate CS just after you think you got complete response for the command. Perform 8 more spare clock cycles before you deactivate CS;
I am not sure but pictures show that you put data onto the SD-card inputs on positive edge of the SD-card clock. As I recall SD-card latches data on positive edge of its clock, thus putting data there at the same time may violate timing. In my implementation, if I recall properly, I put data onto SD-card input lines on negedge, so that it samples it on next posedge.