README
======
This README discusses issues unique to NuttX configurations for the
STMicro STM32F746G-DISCO development board featuring the STM32F746NGH6
MCU. The STM32F746NGH6 is a 216MHz Cortex-M7 operation with 1024Kb Flash
memory and 300Kb SRAM. The board features:
- On-board ST-LINK/V2 for programming and debugging,
- Mbed-enabled (mbed.org)
- 4.3-inch 480x272 color LCD-TFT with capacitive touch screen
- Camera connector
- SAI audio codec
- Audio line in and line out jack
- Stereo speaker outputs
- Two ST MEMS microphones
- SPDIF RCA input connector
- Two pushbuttons (user and reset)
- 128-Mbit Quad-SPI Flash memory
- 128-Mbit SDRAM (64 Mbits accessible)
- Connector for microSD card
- RF-EEPROM daughterboard connector
- USB OTG HS with Micro-AB connectors
- USB OTG FS with Micro-AB connectors
- Ethernet connector compliant with IEEE-802.3-2002
Refer to the http://www.st.com website for further information about this
board (search keyword: stm32f746g-disco)
Contents
========
- Development Environment
- LEDs and Buttons
- Serial Console
- FPU
- STM32F746G-DISCO-specific Configuration Options
- Configurations
Development Environment
=======================
The Development environments for the STM32F746G-DISCO board are identical
to the environments for other STM32F boards. For full details on the
environment options and setup, see the README.txt file in the
config/stm32f746g-disco directory.
LEDs and Buttons
================
LEDs
----
The STM32F746G-DISCO board has numerous LEDs but only one, LD1 located
near the reset button, that can be controlled by software (LD2 is a power
indicator, LD3-6 indicate USB status, LD7 is controlled by the ST-Link).
LD1 is controlled by PI1 which is also the SPI2_SCK at the Arduino
interface. One end of LD1 is grounded so a high output on PI1 will
illuminate the LED.
This LED is not used by the board port unless CONFIG_ARCH_LEDS is defined.
In that case, the usage by the board port is defined in include/board.h
and src/stm32_leds.c. The LEDs are used to encode OS-related events as
follows:
SYMBOL Meaning LD1
------------------- ----------------------- ------
LED_STARTED NuttX has been started OFF
LED_HEAPALLOCATE Heap has been allocated OFF
LED_IRQSENABLED Interrupts enabled OFF
LED_STACKCREATED Idle stack created ON
LED_INIRQ In an interrupt N/C
LED_SIGNAL In a signal handler N/C
LED_ASSERTION An assertion failed N/C
LED_PANIC The system has crashed FLASH
Thus is LD1 is statically on, NuttX has successfully booted and is,
apparently, running normally. If LD1 is flashing at approximately
2Hz, then a fatal error has been detected and the system has halted.
Buttons
-------
Pushbutton B1, labelled "User", is connected to GPIO PI11. A high
value will be sensed when the button is depressed.
Serial Console
==============
These configurations assume that you are using a standard Arduio RS-232
shield with the serial interface with RX on pin D0 and TX on pin D1:
-------- ---------------
STM32F7
ARDUIONO FUNCTION GPIO
-- ----- --------- -----
DO RX USART6_RX PC7
D1 TX USART6_TX PC6
-- ----- --------- -----
FPU
===
FPU Configuration Options
-------------------------
There are two version of the FPU support built into the STM32 port.
1. Lazy Floating Point Register Save.
This is an implementation that saves and restores FPU registers only on
context switches. This means: (1) floating point registers are not
stored on each context switch and, hence, possibly better interrupt
performance. But, (2) since floating point registers are not saved,
you cannot use floating point operations within interrupt handlers.
This logic can be enabled by simply adding the following to your .config
file:
CONFIG_ARCH_FPU=y
CONFIG_ARMV7M_CMNVECTOR=y
CONFIG_ARMV7M_LAZYFPU=y
2. Non-Lazy Floating Point Register Save
Mike Smith has contributed an extensive re-write of the ARMv7-M exception
handling logic. This includes verified support for the FPU. These changes
have not yet been incorporated into the mainline and are still considered
experimental. These FPU logic can be enabled with:
CONFIG_ARCH_FPU=y
CONFIG_ARMV7M_CMNVECTOR=y
You will probably also changes to the ld.script in if this option is selected.
This should work:
-ENTRY(_stext)
+ENTRY(__start) /* Treat __start as the anchor for dead code stripping */
+EXTERN(_vectors) /* Force the vectors to be included in the output */
STM32F746G-DISCO-specific Configuration Options
===============================================
CONFIG_ARCH - Identifies the arch/ subdirectory. This should
be set to:
CONFIG_ARCH=arm
CONFIG_ARCH_family - For use in C code:
CONFIG_ARCH_ARM=y
CONFIG_ARCH_architecture - For use in C code:
CONFIG_ARCH_CORTEXM4=y
CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory
CONFIG_ARCH_CHIP=stm32
CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
chip:
CONFIG_ARCH_CHIP_STM32F746=y
CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG - Enables special STM32 clock
configuration features.
CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG=n
CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD=STM32F746G-DISCO (for the STM32F746G-DISCO development board)
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_STM32F746G_DISCO=y
CONFIG_ARCH_LOOPSPERMSEC - Must be calibrated for correct operation
of delay loops
CONFIG_ENDIAN_BIG - define if big endian (default is little
endian)
CONFIG_RAM_SIZE - Describes the installed DRAM (SRAM in this case):
CONFIG_RAM_SIZE=0x00010000 (64Kb)
CONFIG_RAM_START - The start address of installed DRAM
CONFIG_RAM_START=0x20000000
In order to use FSMC SRAM, the following additional things need to be
present in the NuttX configuration file:
CONFIG_STM32F7_FSMC_SRAM - Indicates that SRAM is available via the
FSMC (as opposed to an LCD or FLASH).
CONFIG_HEAP2_BASE - The base address of the SRAM in the FSMC address space (hex)
CONFIG_HEAP2_SIZE - The size of the SRAM in the FSMC address space (decimal)
CONFIG_ARCH_FPU - The STM32F746G-DISCO supports a floating point unit (FPU)
CONFIG_ARCH_FPU=y
CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to boards that
have LEDs
CONFIG_ARCH_INTERRUPTSTACK - This architecture supports an interrupt
stack. If defined, this symbol is the size of the interrupt
stack in bytes. If not defined, the user task stacks will be
used during interrupt handling.
CONFIG_ARCH_STACKDUMP - Do stack dumps after assertions
CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to board architecture.
CONFIG_ARCH_CALIBRATION - Enables some build in instrumentation that
cause a 100 second delay during boot-up. This 100 second delay
serves no purpose other than it allows you to calibratre
CONFIG_ARCH_LOOPSPERMSEC. You simply use a stop watch to measure
the 100 second delay then adjust CONFIG_ARCH_LOOPSPERMSEC until
the delay actually is 100 seconds.
Individual subsystems can be enabled:
APB1
----
CONFIG_STM32F7_TIM2 TIM2
CONFIG_STM32F7_TIM3 TIM3
CONFIG_STM32F7_TIM4 TIM4
CONFIG_STM32F7_TIM5 TIM5
CONFIG_STM32F7_TIM6 TIM6
CONFIG_STM32F7_TIM7 TIM7
CONFIG_STM32F7_TIM12 TIM12
CONFIG_STM32F7_TIM13 TIM13
CONFIG_STM32F7_TIM14 TIM14
CONFIG_STM32F7_LPTIM1 LPTIM1
CONFIG_STM32F7_RTC RTC
CONFIG_STM32F7_BKP BKP Registers
CONFIG_STM32F7_WWDG WWDG
CONFIG_STM32F7_IWDG IWDG
CONFIG_STM32F7_SPI2 SPI2
CONFIG_STM32F7_I2S2 I2S2
CONFIG_STM32F7_SPI3 SPI3
CONFIG_STM32F7_I2S3 I2S3
CONFIG_STM32F7_SPDIFRX SPDIFRX
CONFIG_STM32F7_USART2 USART2
CONFIG_STM32F7_USART3 USART3
CONFIG_STM32F7_UART4 UART4
CONFIG_STM32F7_UART5 UART5
CONFIG_STM32F7_I2C1 I2C1
CONFIG_STM32F7_I2C2 I2C2
CONFIG_STM32F7_I2C3 I2C3
CONFIG_STM32F7_I2C4 I2C4
CONFIG_STM32F7_CAN1 CAN1
CONFIG_STM32F7_CAN2 CAN2
CONFIG_STM32F7_HDMICEC HDMI-CEC
CONFIG_STM32F7_PWR PWR
CONFIG_STM32F7_DAC DAC
CONFIG_STM32F7_UART7 UART7
CONFIG_STM32F7_UART8 UART8
APB2
----
CONFIG_STM32F7_TIM1 TIM1
CONFIG_STM32F7_TIM8 TIM8
CONFIG_STM32F7_USART1 USART1
CONFIG_STM32F7_USART6 USART6
CONFIG_STM32F7_ADC ADC1 - ADC2 - ADC3
CONFIG_STM32F7_SDMMC1 SDMMC1
CONFIG_STM32F7_SPI1 SPI1
CONFIG_STM32F7_SPI4 SPI4
CONFIG_STM32F7_SYSCFG SYSCFG
CONFIG_STM32F7_EXTI EXTI
CONFIG_STM32F7_TIM9 TIM9
CONFIG_STM32F7_TIM10 TIM10
CONFIG_STM32F7_TIM11 TIM11
CONFIG_STM32F7_SPI5 SPI5
CONFIG_STM32F7_SPI6 SPI6
CONFIG_STM32F7_SAI1 SAI1
CONFIG_STM32F7_SAI2 SAI2
CONFIG_STM32F7_LTDC LCD-TFT
AHB1
----
CONFIG_STM32F7_CRC CRC
CONFIG_STM32F7_BKPSRAM BKPSRAM
CONFIG_STM32F7_DMA1 DMA1
CONFIG_STM32F7_DMA2 DMA2
CONFIG_STM32F7_ETHMAC Ethernet MAC
CONFIG_STM32F7_DMA2D Chrom-ART (DMA2D)
CONFIG_STM32F7_USBOTGHS USB OTG HS
AHB2
----
CONFIG_STM32F7_USBOTGFS USB OTG FS
CONFIG_STM32F7_DCMI DCMI
CONFIG_STM32F7_CRYP CRYP
CONFIG_STM32F7_HASH HASH
CONFIG_STM32F7_RNG RNG
AHB3
----
CONFIG_STM32F7_FSMC FSMC control registers
CONFIG_STM32F7_QUADSPI QuadSPI Control
Timer devices may be used for different purposes. One special purpose is
to generate modulated outputs for such things as motor control. If CONFIG_STM32F7_TIMn
is defined (as above) then the following may also be defined to indicate that
the timer is intended to be used for pulsed output modulation, ADC conversion,
or DAC conversion. Note that ADC/DAC require two definition: Not only do you have
to assign the timer (n) for used by the ADC or DAC, but then you also have to
configure which ADC or DAC (m) it is assigned to.
CONFIG_STM32F7_TIMn_PWM Reserve timer n for use by PWM, n=1,..,14
CONFIG_STM32F7_TIMn_ADC Reserve timer n for use by ADC, n=1,..,14
CONFIG_STM32F7_TIMn_ADCm Reserve timer n to trigger ADCm, n=1,..,14, m=1,..,3
CONFIG_STM32F7_TIMn_DAC Reserve timer n for use by DAC, n=1,..,14
CONFIG_STM32F7_TIMn_DACm Reserve timer n to trigger DACm, n=1,..,14, m=1,..,2
For each timer that is enabled for PWM usage, we need the following additional
configuration settings:
CONFIG_STM32F7_TIMx_CHANNEL - Specifies the timer output channel {1,..,4}
NOTE: The STM32 timers are each capable of generating different signals on
each of the four channels with different duty cycles. That capability is
not supported by this driver: Only one output channel per timer.
JTAG Enable settings (by default only SW-DP is enabled):
CONFIG_STM32F7_JTAG_FULL_ENABLE - Enables full SWJ (JTAG-DP + SW-DP)
CONFIG_STM32F7_JTAG_NOJNTRST_ENABLE - Enables full SWJ (JTAG-DP + SW-DP)
but without JNTRST.
CONFIG_STM32F7_JTAG_SW_ENABLE - Set JTAG-DP disabled and SW-DP enabled
STM32F746G-DISCO specific device driver settings
CONFIG_U[S]ARTn_SERIAL_CONSOLE - selects the USARTn (n=1,2,3) or UART
m (m=4,5) for the console and ttys0 (default is the USART1).
CONFIG_U[S]ARTn_RXBUFSIZE - Characters are buffered as received.
This specific the size of the receive buffer
CONFIG_U[S]ARTn_TXBUFSIZE - Characters are buffered before
being sent. This specific the size of the transmit buffer
CONFIG_U[S]ARTn_BAUD - The configure BAUD of the UART. Must be
CONFIG_U[S]ARTn_BITS - The number of bits. Must be either 7 or 8.
CONFIG_U[S]ARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
CONFIG_U[S]ARTn_2STOP - Two stop bits
STM32F746G-DISCO CAN Configuration
CONFIG_CAN - Enables CAN support (one or both of CONFIG_STM32F7_CAN1 or
CONFIG_STM32F7_CAN2 must also be defined)
CONFIG_CAN_EXTID - Enables support for the 29-bit extended ID. Default
Standard 11-bit IDs.
CONFIG_CAN_FIFOSIZE - The size of the circular buffer of CAN messages.
Default: 8
CONFIG_CAN_NPENDINGRTR - The size of the list of pending RTR requests.
Default: 4
CONFIG_CAN_LOOPBACK - A CAN driver may or may not support a loopback
mode for testing. The STM32 CAN driver does support loopback mode.
CONFIG_CAN1_BAUD - CAN1 BAUD rate. Required if CONFIG_STM32F7_CAN1 is defined.
CONFIG_CAN2_BAUD - CAN1 BAUD rate. Required if CONFIG_STM32F7_CAN2 is defined.
CONFIG_CAN_TSEG1 - The number of CAN time quanta in segment 1. Default: 6
CONFIG_CAN_TSEG2 - the number of CAN time quanta in segment 2. Default: 7
CONFIG_CAN_REGDEBUG - If CONFIG_DEBUG is set, this will generate an
dump of all CAN registers.
STM32F746G-DISCO SPI Configuration
CONFIG_STM32F7_SPI_INTERRUPTS - Select to enable interrupt driven SPI
support. Non-interrupt-driven, poll-waiting is recommended if the
interrupt rate would be to high in the interrupt driven case.
CONFIG_STM32F7_SPI_DMA - Use DMA to improve SPI transfer performance.
Cannot be used with CONFIG_STM32F7_SPI_INTERRUPT.
STM32F746G-DISCO DMA Configuration
CONFIG_SDIO_DMA - Support DMA data transfers. Requires CONFIG_STM32F7_SDIO
and CONFIG_STM32F7_DMA2.
CONFIG_SDIO_PRI - Select SDIO interrupt prority. Default: 128
CONFIG_SDIO_DMAPRIO - Select SDIO DMA interrupt priority.
Default: Medium
CONFIG_SDIO_WIDTH_D1_ONLY - Select 1-bit transfer mode. Default:
4-bit transfer mode.
STM32 USB OTG FS Host Driver Support
Pre-requisites
CONFIG_USBDEV - Enable USB device support
CONFIG_USBHOST - Enable USB host support
CONFIG_STM32F7_OTGFS - Enable the STM32 USB OTG FS block
CONFIG_STM32F7_SYSCFG - Needed
CONFIG_SCHED_WORKQUEUE - Worker thread support is required
Options:
CONFIG_STM32F7_OTGFS_RXFIFO_SIZE - Size of the RX FIFO in 32-bit words.
Default 128 (512 bytes)
CONFIG_STM32F7_OTGFS_NPTXFIFO_SIZE - Size of the non-periodic Tx FIFO
in 32-bit words. Default 96 (384 bytes)
CONFIG_STM32F7_OTGFS_PTXFIFO_SIZE - Size of the periodic Tx FIFO in 32-bit
words. Default 96 (384 bytes)
CONFIG_STM32F7_OTGFS_DESCSIZE - Maximum size of a descriptor. Default: 128
CONFIG_STM32F7_OTGFS_SOFINTR - Enable SOF interrupts. Why would you ever
want to do that?
CONFIG_STM32F7_USBHOST_REGDEBUG - Enable very low-level register access
debug. Depends on CONFIG_DEBUG.
CONFIG_STM32F7_USBHOST_PKTDUMP - Dump all incoming and outgoing USB
packets. Depends on CONFIG_DEBUG.
Configurations
==============
Each STM32F746G-DISCO configuration is maintained in a sub-directory and
can be selected as follow:
cd tools
./configure.sh stm32f746g-disco/<subdir>
cd -
. ./setenv.sh
If this is a Windows native build, then configure.bat should be used
instead of configure.sh:
configure.bat STM32F746G-DISCO\<subdir>
Where <subdir> is one of the following:
nsh:
---
Configures the NuttShell (nsh) located at apps/examples/nsh. The
Configuration enables the serial interfaces on UART2. Support for
builtin applications is enabled, but in the base configuration no
builtin applications are selected (see NOTES below).
NOTES:
1. This configuration uses the mconf-based configuration tool. To
change this configuration using that tool, you should:
a. Build and install the kconfig-mconf tool. See nuttx/README.txt
see additional README.txt files in the NuttX tools repository.
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. By default, this configuration uses the CodeSourcery toolchain
for Windows and builds under Cygwin (or probably MSYS). That
can easily be reconfigured, of course.
CONFIG_HOST_WINDOWS=y : Builds under Windows
CONFIG_WINDOWS_CYGWIN=y : Using Cygwin
CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery for Windows
3. This example supports the PWM test (apps/examples/pwm) but this must
be manually enabled by selecting:
CONFIG_PWM=y : Enable the generic PWM infrastructure
CONFIG_STM32F7_TIM4=y : Enable TIM4
CONFIG_STM32F7_TIM4_PWM=y : Use TIM4 to generate PWM output
See also apps/examples/README.txt
Special PWM-only debug options:
CONFIG_DEBUG_PWM
5. This example supports the Quadrature Encode test (apps/examples/qencoder)
but this must be manually enabled by selecting:
CONFIG_EXAMPLES_QENCODER=y : Enable the apps/examples/qencoder
CONFIG_SENSORS=y : Enable support for sensors
CONFIG_QENCODER=y : Enable the generic Quadrature Encoder infrastructure
CONFIG_STM32F7_TIM8=y : Enable TIM8
CONFIG_STM32F7_TIM2=n : (Or optionally TIM2)
CONFIG_STM32F7_TIM8_QE=y : Use TIM8 as the quadrature encoder
CONFIG_STM32F7_TIM2_QE=y : (Or optionally TIM2)
See also apps/examples/README.txt. Special debug options:
CONFIG_DEBUG_SENSORS
6. This example supports the watchdog timer test (apps/examples/watchdog)
but this must be manually enabled by selecting:
CONFIG_EXAMPLES_WATCHDOG=y : Enable the apps/examples/watchdog
CONFIG_WATCHDOG=y : Enables watchdog timer driver support
CONFIG_STM32F7_WWDG=y : Enables the WWDG timer facility, OR
CONFIG_STM32F7_IWDG=y : Enables the IWDG timer facility (but not both)
The WWDG watchdog is driven off the (fast) 42MHz PCLK1 and, as result,
has a maximum timeout value of 49 milliseconds. for WWDG watchdog, you
should also add the fillowing to the configuration file:
CONFIG_EXAMPLES_WATCHDOG_PINGDELAY=20
CONFIG_EXAMPLES_WATCHDOG_TIMEOUT=49
The IWDG timer has a range of about 35 seconds and should not be an issue.
7. USB Support (CDC/ACM device)
CONFIG_STM32F7_OTGFS=y : STM32 OTG FS support
CONFIG_USBDEV=y : USB device support must be enabled
CONFIG_CDCACM=y : The CDC/ACM driver must be built
CONFIG_NSH_BUILTIN_APPS=y : NSH built-in application support must be enabled
CONFIG_NSH_ARCHINIT=y : To perform USB initialization
8. Using the USB console.
The STM32F746G-DISCO NSH configuration can be set up to use a USB CDC/ACM
(or PL2303) USB console. The normal way that you would configure the
the USB console would be to change the .config file like this:
CONFIG_STM32F7_OTGFS=y : STM32 OTG FS support
CONFIG_USART2_SERIAL_CONSOLE=n : Disable the USART2 console
CONFIG_DEV_CONSOLE=n : Inhibit use of /dev/console by other logic
CONFIG_USBDEV=y : USB device support must be enabled
CONFIG_CDCACM=y : The CDC/ACM driver must be built
CONFIG_CDCACM_CONSOLE=y : Enable the CDC/ACM USB console.
NOTE: When you first start the USB console, you have hit ENTER a few
times before NSH starts. The logic does this to prevent sending USB data
before there is anything on the host side listening for USB serial input.
9. Here is an alternative USB console configuration. The following
configuration will also create a NSH USB console but this version
will use /dev/console. Instead, it will use the normal /dev/ttyACM0
USB serial device for the console:
CONFIG_STM32F7_OTGFS=y : STM32 OTG FS support
CONFIG_USART2_SERIAL_CONSOLE=y : Keep the USART2 console
CONFIG_DEV_CONSOLE=y : /dev/console exists (but NSH won't use it)
CONFIG_USBDEV=y : USB device support must be enabled
CONFIG_CDCACM=y : The CDC/ACM driver must be built
CONFIG_CDCACM_CONSOLE=n : Don't use the CDC/ACM USB console.
CONFIG_NSH_USBCONSOLE=y : Instead use some other USB device for the console
The particular USB device that is used is:
CONFIG_NSH_USBCONDEV="/dev/ttyACM0"
The advantage of this configuration is only that it is easier to
bet working. This alternative does has some side effects:
- When any other device other than /dev/console is used for a user
interface, linefeeds (\n) will not be expanded to carriage return /
linefeeds (\r\n). You will need to set your terminal program to account
for this.
- /dev/console still exists and still refers to the serial port. So
you can still use certain kinds of debug output (see include/debug.h, all
of the interfaces based on lowsyslog will work in this configuration).
- But don't enable USB debug output! Since USB is console is used for
USB debug output and you are using a USB console, there will be
infinite loops and deadlocks: Debug output generates USB debug
output which generatates USB debug output, etc. If you want USB
debug output, you should consider enabling USB trace
(CONFIG_USBDEV_TRACE) and perhaps the USB monitor (CONFIG_SYSTEM_USBMONITOR).
See the usbnsh configuration below for more information on configuring
USB trace output and the USB monitor.
10. USB OTG FS Host Support. The following changes will enable support for
a USB host on the STM32F746G-DISCO, including support for a mass storage
class driver:
Device Drivers ->
CONFIG_USBDEV=n : Make sure tht USB device support is disabled
CONFIG_USBHOST=y : Enable USB host support
CONFIG_USBHOST_ISOC_DISABLE=y
Device Drivers -> USB Host Driver Support
CONFIG_USBHOST_MSC=y : Enable the mass storage class
System Type -> STM32 Peripheral Support
CONFIG_STM32F7_OTGHS=y : Enable the STM32 USB OTG FH block (FS mode)
CONFIG_STM32F7_SYSCFG=y : Needed for all USB OTF HS support
RTOS Features -> Work Queue Support
CONFIG_SCHED_WORKQUEUE=y : High priority worker thread support is required
CONFIG_SCHED_HPWORK=y : for the mass storage class driver.
File Systems ->
CONFIG_FS_FAT=y : Needed by the USB host mass storage class.
Board Selection ->
CONFIG_LIB_BOARDCTL=y : Needed for CONFIG_NSH_ARCHINIT
Application Configuration -> NSH Library
CONFIG_NSH_ARCHINIT=y : Architecture specific USB initialization
: is needed for NSH
With those changes, you can use NSH with a FLASH pen driver as shown
belong. Here NSH is started with nothing in the USB host slot:
NuttShell (NSH) NuttX-x.yy
nsh> ls /dev
/dev:
console
null
ttyS0
After inserting the FLASH drive, the /dev/sda appears and can be
mounted like this:
nsh> ls /dev
/dev:
console
null
sda
ttyS0
nsh> mount -t vfat /dev/sda /mnt/stuff
nsh> ls /mnt/stuff
/mnt/stuff:
-rw-rw-rw- 16236 filea.c
And files on the FLASH can be manipulated to standard interfaces:
nsh> echo "This is a test" >/mnt/stuff/atest.txt
nsh> ls /mnt/stuff
/mnt/stuff:
-rw-rw-rw- 16236 filea.c
-rw-rw-rw- 16 atest.txt
nsh> cat /mnt/stuff/atest.txt
This is a test
nsh> cp /mnt/stuff/filea.c fileb.c
nsh> ls /mnt/stuff
/mnt/stuff:
-rw-rw-rw- 16236 filea.c
-rw-rw-rw- 16 atest.txt
-rw-rw-rw- 16236 fileb.c
To prevent data loss, don't forget to un-mount the FLASH drive
before removing it:
nsh> umount /mnt/stuff
11. I used this configuration to test the USB hub class. I did this
testing with the following changes to the configuration (in addition
to those listed above for base USB host/mass storage class support):
Drivers -> USB Host Driver Support
CONFIG_USBHOST_HUB=y : Enable the hub class
CONFIG_USBHOST_ASYNCH=y : Asynchonous I/O supported needed for hubs
Board Selection ->
CONFIG_STM32F746GDISCO_USBHOST_STACKSIZE=2048 (bigger than it needs to be)
RTOS Features -> Work Queue Support
CONFIG_SCHED_LPWORK=y : Low priority queue support is needed
CONFIG_SCHED_LPNTHREADS=1
CONFIG_SCHED_LPWORKSTACKSIZE=1024
NOTES:
1. It is necessary to perform work on the low-priority work queue
(vs. the high priority work queue) because deferred hub-related
work requires some delays and waiting that is not appropriate on
the high priority work queue.
2. Stack usage make increase when USB hub support is enabled because
the nesting depth of certain USB host class logic can increase.
