This NES Classic NAND image is dumped by someone. I downloaded it from rendezvo
The bootrom(U-Boot) may boot from 0x1000 or 0x2000 in NAND. Reference
According to m0skit0 (Stack Overflow), the sequence of 7f 45 4c 46 represents an ELF entry. In this NAND image , there are several addresses that match the sequence. The addresses are as follow:
0x7B60B10x7F2A130x8459AC0x8AF8BE
The CPU (Allwinner R16/A33) features quad-core Cortex-A7.