ARM Software FAQs¶

Useful memory locations¶

Two useful linux memory tools: devmem2 and mem_util

AM57x TRM
https://www.ti.com/lit/ug/spruhz6l/spruhz6l.pdf

• Control Module
  Control Module base address: 0x4A00_2000
  AM57x TRM Table 18-28. CTRL_MODULE_CORE Registers Mapping Summary pg4213
  • Pinmux
    NOTE: TI says you can only change the pinmux from the MLO, so this should be read-only. See Setup Pinmux
    AM57x TRM 18.4.6.1.1 Pad Configuration Registers pg4174
    CTRL_CORE_PAD_UART1_RXD 0x4A00_37E0
    CTRL_CORE_PAD_UART1_TXD 0x4A00_37E4
• GPIO Modules
  AM57x TRM 27.6.1 General-Purpose Interface Instance Summary pg7108
  GPIO_OE Offset 0x0134
  GPIO_DATAIN Offset 0x0138
  GPIO_DATAOUT Offset 0x013C

USB1 3.0 Benchmark¶

Note you can use lsusb to check the link speed of your devices. One of the usb-storage drives is plugged into the 2.0 hub so is linked at 480M (USB2.0 speeds) and one is plugged into the USB-C connector and is linked at 5000M (USB3.0 speeds).

root@mitysom-am57x:~# lsusb -t
/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 5000M
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
        |__ Port 1: Dev 3, If 0, Class=Mass Storage, Driver=usb-storage, 480M
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 5000M
    |__ Port 1: Dev 2, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 480M

USB1

Testing using a USB-C nvme enclosure. "Rongdeson USB3.1 Type-C to NVMe M.2 SSD Enclosure" with a "Samsung 970 Evo NVMe M.2" drive

256MB/s write (2048Mbps), 359MB/s (2872Mbps) read (I get closer to 900MB/s read on my PC)

root@mitysom-am57x:/run/media/sda1# time bonnie++ -u root -d /run/media/sda1/ -n 1024 -m "1TB nvme USB-c AM57x" 
...
Version  1.04       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
1TB nvme USB-c A 4G 46175  98 235618  93 158226  68 50469  99 358888  79 +++++ +++
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
               1024 14813  97 38651  89 12437  84 14817  96 36224  91 11762  85
1TB nvme USB-c AM57x,4G,46175,98,235618,93,158226,68,50469,99,358888,79,+++++,+++,1024,14813,97,38651,89,12437,84,14817,96,36224,91,11762,85
real    10m 12.68s
user    2m 35.50s
sys     6m 41.97s

Tested rndis. Got 612Mb/s tx, 456Mb/s rx

root@mitysom-am57x:~# iperf3 -c 192.168.1.2
Connecting to host 192.168.1.2, port 5201
[  5] local 192.168.1.1 port 46708 connected to 192.168.1.2 port 5201
...
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   730 MBytes   612 Mbits/sec    0             sender
[  5]   0.00-10.00  sec   729 MBytes   612 Mbits/sec                  receiver

iperf Done.
root@mitysom-am57x:~# iperf3 -c 192.168.1.2 --reverse
Connecting to host 192.168.1.2, port 5201
Reverse mode, remote host 192.168.1.2 is sending
...
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   544 MBytes   456 Mbits/sec    0             sender
[  5]   0.00-10.00  sec   543 MBytes   456 Mbits/sec                  receiver

iperf Done.