[U-Boot-Users] IO access in U-BOOT

hi,

I use the ARM926ejs, it need set the I/O as input, output or other status. Also it need read the I/O port.And "all IO is memory mapped". In u-boot how to support this, where to configure it, or it need write by myself.

Another question, in uboot, the irq of ARM926ejs was closed by a macro CONFIG_USE_IRQ. So the irq interrupt is no used, then how u-boot support the keyboard, network, and IDE hard disk, polling? if need support USB, can it still use polling driver?

Does someone have more document about the u-boot, I really need

Thank you

Terry