Differences between Jetson TX2 revisions B02,D00, and D02

Is there functional differences between different Jetson TX2 board revisions?
I encountered some anomaly when using Jetpack 3.3.3 , 4.4 and 4.4.1 versions on B02 and D02 module revisions. D00 is working presumably as same as B02 (not 100 % sure what memory is in D00)

B02 is using Samsung 8Gb per die memories while D02 is using Micron 16Gb per die memory.
However when checking from U-boot and from Linux available memory is not the same with B02 and D02 revision modules.

U-boot reports roughly 7.8 gigabytes available memory on B02 revision board with Jetpacks 3.3.3 ,4.4 and 4.4.1. However D02 reports only 7.7 gigabytes of available memory.

See details below:

U-boot bdinfo from B02 and Jetpack 4.4.1

arch_number = 0x00000000
boot_params = 0x00000000
DRAM bank = 0x00000000
-> start = 0x80000000
-> size = 0x70000000
DRAM bank = 0x00000001
-> start = 0xF0200000
-> size = 0x185600000
DRAM bank = 0x00000002
-> start = 0x275E00000
-> size = 0x00200000
DRAM bank = 0x00000004
-> start = 0x277000000
-> size = 0x00200000

< removed most of empty banks due size restriction in post>

DRAM bank = 0x00000400
-> start = 0x00000000
-> size = 0x00000000
DRAM bank = 0x00000401
-> start = 0x00000000
-> size = 0x00000000
baudrate = 115200 bps
TLB addr = 0xFFFF0000
relocaddr = 0xFFF37000
reloc off = 0x7FEB7000
irq_sp = 0xFFB2E210
sp start = 0xFFB2E210

U-boot bdinfo from D02 and Jetpack 4.4.1

arch_number = 0x00000000
boot_params = 0x00000000
DRAM bank = 0x00000000
-> start = 0x80000000
-> size = 0x70000000
DRAM bank = 0x00000001
-> start = 0xF0200000
-> size = 0x179E00000
DRAM bank = 0x00000002
-> start = 0x26A600000
-> size = 0x00200000
DRAM bank = 0x00000003
-> start = 0x26AE00000
-> size = 0x00200000

< removed most of empty banks due size restriction in post>

DRAM bank = 0x00000400
-> start = 0x00000000
-> size = 0x00000000
DRAM bank = 0x00000401
-> start = 0x00000000
-> size = 0x00000000
baudrate = 115200 bps
TLB addr = 0xFFFF0000
relocaddr = 0xFFF37000
reloc off = 0x7FEB7000
irq_sp = 0xFFB2E210
sp start = 0xFFB2E210

Also sheer amount of DRAM banks in both cases is overwhelming. However main issue is that with B02 DRAM Bank 1 has settings like:

DRAM bank = 0x00000001
-> start = 0xF0200000
-> size = 0x185600000

However with D02 this not the same:

DRAM bank = 0x00000001
-> start = 0xF0200000
-> size = 0x179E00000

Difference is around 184 megabytes, which is bit odd from my point of view as there should not be size difference.
Rest of the valid DRAM banks are the same in both revisions (however, why there is so many empty DRAM banks defined is beyond me).

Any ideas what is causing this?

Hi, there should be no functional difference among them. There might be some memory config difference on memory chip of different vendor which is acceptable. You can file a topic if really meet a issue on this.

Hi,

From related PCN I got impression that Jetpack 3.3.3 and Jetpack 4.4 (or later) should have support for the Micron memory. With Jetpack 3.2 where support does not exist, D02 revision board which we have, will not boot correctly as there is no memory configuration present for the Micron memory. With 4.4.1 device boots correctly, but amount of memory available is not the same as with B02 revision board.

I’ll discuss internally at our end how this will be handled.