I am trying to boot a Zynq 7000 board using petalinux by tftpboot. Do I still need a SD card?
SD card is not mandatory. But you need a storage device to load FSBL, U-Boot, etc. It can be a QSPI flash, SD card, eMMC chip, ... If your board has QSPI flash, then you can boot from it and use tftpboot without an SD card.