Memory map

The same memory map exists at 0x00000000 and 0x80000000, with the difference that the first alias is for cached access, and the second is for uncached access.

cached	uncached	name	description
0x00000000	0x80000000		internal RAM (0x2000 bytes)
0x00002000	0x80002000		DRAM (repeats to fill address space until 0x20000000)
--	0xb0000000	GCR	System Global Control Registers
--	0xb0000200	CLK	Clock Registers
--	0xb0001000	MC	Memory controller
--	0xb0002000	MAC1	Ethernet MAC 1
--	0xb0003000	MAC2	Ethernet MAC 2
--	0xb0004000	GDMA	DMA engine (?)
--	0xb0005000	USB2	USB 2.0 device controller
--	0xb0006000	USB1	USB 1.1 device controller
--	0xb0007000	SDHC	SD Card host controller
--	0xb0018000	VCD	video capture device
--	0xb8000000	UART0	UART0
--	0xb8000100	UART1	UART1
--	0xb8000200	PECI	PECI controller
--	0xb8000300	GFXI	graphics interface
--	0xb8000400	SSPI	secondary SPI controller
--	0xb8001000	TIMER	Timers
--	0xb8002000	AIC	Interrupt controller
--	0xb8003000	GPIO	GPIOs
--	0xb8004000	TACH0	tachometer 0
--	0xb8005000	TACH1	tachometer 1
--	0xb8006000	I2C	I2C controllers
--	0xb8007000	PWM	Pulse-width modulation
--	0xb8008000	KCS	IPMI KCS and POST code monitor
--	0xb8009000	ADC	Analog-digital converter
--	0xb800a000	RNG	Random number generator
--	0xb800b000	AES	AES engine
0x40000000	0xc0000000		memory-mapped SPI flash
0x44000000	0xc4000000	XBUS	external bus (XBUS)
0x46000000	0xc6000000		internal RAM, 0x400 bytes
--	0xc8000000	FIU	boot SPI flash controller
--	0xc8001000	SHM	Shared memory controller
0x7fff0000	0xffff0000		Boot ROM

Buses

• The ATEN kernel indicates that AHB starts at 0xb0000000 and APB starts at 0xb8000000.

ATEN kernel

The ATEN kernel installs the following mappings, to be used from the kernel and from userspace:

physical	virtual	size	description
0xb0000000	0xf0010000	0x00010000 (64k)	AHB, I/O devices
0xb0010000	0xf0020000	0x00010000 (64k)	VCD
0xb8000000	0xf0030000	0x00010000 (64k)	APB, more I/O devices
0x06400000	0xf0100000	0x02000000 (32M)	VCD memory, part of RAM

Note that the VCDMEM mapping is longer than it should be: 0x06400000 + 0x02000000 = 0x08400000. As a result, the first 4 MiB of RAM are also accessible to all userspace.

References

• Memory map: AMI, ATEN