[U-Boot-Users] CFG_INIT_DCACHE_CS

Hello. Everyone. Now I am trying to port ppcboot to a simple custom board, with ppc405cr, 32M RAM, 4M EEPROM, JTAG, UART.

I can not understand some Marcos in the header file include/configs/xxx.h.

#define CFG_INIT_DCACHE_CS 4 /* use cs # 4 for data cache memory */

there is no OCM in 405CR, so ppcboot needs data cache for initial stacks and data. but what does the "chip select" mean?

As I know, chip select should be used on some peripheral devices, like Flash, NVRAM, why is it needed for data cache which is inside the CPU core?

Is the CS only a concept inside ppcboot? or something according to the hardware?

thanks a lot in advance.

maoyuan