Useful Stuff

Drop point for anything useful, notes and cribs that doesn't fit anywhere else....

BeagleBone Black notes

Ethernet

Originally during the BBB development it was envisaged that the MAC address for Ethernet would need to be provided on the SPI EEPROM. Space was provisioned for just this purpose, however the AM335x SoC has unique Ethernet MAC addresses on-board. Whilst this can be overridden in uboot (or from the kernel) the MAC is correctly loaded at boot time by uboot and passed to the kernel. That said, it is occasionally useful to read the MAC from the SoC directly.

From the AM335x TRM (section 9.3.1.23 of TRM rev L) we can see that the MAC address is held at offset 0x0630 of the Control Module. The full address is therefore 0x44E1 0630.

USB Hot Plug

BBB did not deal with USB Hotplug until revision A6A. The change despite not being documented is a hardware issue (contra to popular belief that this was a software issue fixed from BBB rev C) is the increase of C106 from 100nF to 1uF. I have successfully modified revision A5C boards by stacking several 100nF caps - I have found a minimum of 300nF is required to make this work, 1uF is preferred.

NOTE C106 has an 0402 footprint. This is not trivial to change by hand unless you have the right equipment and know what you are doing! You have been warned.

board picture

kernel options...

Drivers

Options

Locations

armmp support

USB Core

CONFIG_USB_SUPPORT

USB Support

Y


CONFIG_USB

USB Support
Support for Host-side USB

Y

MUSB Controller

USB Support

CONFIG_USB_MUSB_HDRC

Inventra Highspeed Dual Role

Y

CONFIG_USB_MUSB_DUAL_ROLE

MUSB Mode Selection (Dual Role mode)

Y

CONFIG_USB_MUSB_DSPS

USB Support

m

Inventra Highspeed Dual Role

Platform Glue Layer

TI DSPS platforms

USB PHY

USB Support

USB Physical Layer drivers

CONFIG_AM335X_PHY_USB

AM335x USB PHY Driver

m

CPPI41 DMA

CONFIG_DMADEVICES

DMA Engine support

Y

CONFIG_TI_CPPI41

AM33xx CPPI41 DMA support

m

USB Support

Inventra Highspeed Dual Role

CONFIG_USB_TI_CPPI41_DMA

MUSB DMA mode (TI CPPI 4.1 (AM335x))

not set

armmp support is comparing 4.3.0-rc6 with https://packages.debian.org/sid/armhf/linux-image-4.2.0-1-armmp/download

See also http://processors.wiki.ti.com/index.php/MUSB_Linux_Driver_Configuration

OpenTAC_defconfig may be found in arch/arm/configs in VA Git repo kernel branch

Modules list compared to armmp

Missing in current ARMMP

# CONFIG_I2C_MUX_PCA954x is not set
# CONFIG_SENSORS_PWM_FAN is not set
# CONFIG_USB_SERIAL_CONSOLE is not set
# CONFIG_USB_TI_CPPI41_DMA is not set

Requirements for missing configs:

CONFIG_I2C_MUX_PCA954x=m
CONFIG_SENSORS_PWM_FAN=m
CONFIG_USB_SERIAL_CONSOLE=y
CONFIG_USB_TI_CPPI41_DMA=y

Available as modules in ARMMP

CONFIG_TI_CPPI41=m
CONFIG_TI_AM335X_ADC=m
CONFIG_PWM_TIEHRPWM=m
CONFIG_AM335X_CONTROL_USB=m
CONFIG_AM335X_PHY_USB=m
CONFIG_USB_SERIAL_FTDI_SIO=m
CONFIG_USB_MUSB_DSPS=m
CONFIG_USB_DWC3=m
CONFIG_USB_MUSB_AM335X_CHILD=m

Already enabled but differ from multi_v7_defconfig

CONFIG_USB=y
CONFIG_USB_SUPPORT=y
CONFIG_DMADEVICES=y
CONFIG_USB_MUSB_HDRC=y
CONFIG_PWM_TIPWMSS=y
CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
CONFIG_USB_MUSB_DUAL_ROLE=y
CONFIG_USB_MON=y
CONFIG_USB_SERIAL_GENERIC=y

VeroApparatus: OpenTACUsefulNotes (last edited 2015-11-24 22:15:52 by NeilWilliams)