cache line size 32B
L1 cache 16KB+16KB I+D, virtually indexed / physically addressed
no TCM (tightly coupled memory)

L2 cache 128KB, "primarily used by GPU"
  (by default CPU doesn't see it)

Physical memory map

00000000	256M	dram
  00000000	64		exception vectors
  00000100	7936	boot ATAGs (inc. cmdline.txt)
  00002000	4K		Mach
  00003000	1K		L2 page table for exception vectors
  00003400	3K		- unused -
  00004000	16K		L1 page table for kernel
  00008000  -       default kernel load address
  01000000	16K		u-boot env
20000000	16M		i/o registers

Virtual memory map

00000000	512M	user space
7E000000	16M		i/o registers
80000000	<=224M	kernel ram (reserve some for GPU)
FFFF0000	4K		exception vectors

Linux params at *R2 (default 0x100) are a sequence of ATAGs
  struct atag {
	u32int size;	/* size of ATAG in words, including header */
    u32int tag;		/* ATAG_CORE is first, ATAG_NONE is last */
	u32int data[size-2];
  };
  00000000	ATAG_NONE
  54410001	ATAG_CORE
  54410002	ATAG_MEM
  54410009	ATAG_CMDLINE