Memory map

32-bit MIPS CPUs have cached/uncached views of the same physical address spaces at different "segments", called kseg0, kseg1, etc.

segment	CPU address	description
kuseg	0x00000000	cached, translated access
kseg0	0x80000000	cached, untranslated access
kseg1	0xa0000000	uncached, untranslated access

This means that the size of the physical address space is effectively just 0x20000000 (512 MiB).

physical	kseg0	kseg1	size	description
0x00000000	0x80000000	0xa0000000	64 MiB	DRAM
0x04000000	0x84000000	0xa4000000	64 MiB x N	DRAM (more mirrors)
0x1c000000	0x9c000000	0xbc000000	32 MiB	DRAM (last mirror)
0x1e000000	0x9e000000	0xbe000000	4 MiB	Presumably on-chip RAM
0x1e400000	0x9e400000	0xbe400000	4 MiB	mirror of 0x1e000000
0x1f010000		0xbf010000		SPI0 (read from the first register stalls the CPU)
0x1f060000		0xbf060000		USB 0
0x1f070000		0xbf070000		USB 1
0x1f100000		0xbf100000		Interrupt controller
0x1f140000		0xbf140000
0x1f156000		0xbf156000
0x1f420000		0xbf420000		JPEG engine
0x1f540000		0xbf540000		UART 0
0x1f550000		0xbf550000		UART 1
0x1f5d0000		0xbf5d0000		HDMI controller