README
^^^^^^
This README discusses issues unique to NuttX configurations for the Atmel
SAM4E-EK development. This board features the SAM4E16 MCU running at 96
or 120MHz.
Contents
^^^^^^^^
- Development Environment
- GNU Toolchain Options
- IDEs
- NuttX EABI "buildroot" Toolchain
- NuttX OABI "buildroot" Toolchain
- NXFLAT Toolchain
- Atmel Studio 6.1
- LEDs
- Serial Console
- SAM4E-EK-specific Configuration Options
- Configurations
Development Environment
^^^^^^^^^^^^^^^^^^^^^^^
Either Linux or Cygwin on Windows can be used for the development environment.
The source has been built only using the GNU toolchain (see below). Other
toolchains will likely cause problems. Testing was performed using the Cygwin
environment.
GNU Toolchain Options
^^^^^^^^^^^^^^^^^^^^^
The NuttX make system can be configured to support the various different
toolchain options. All testing has been conducted using the NuttX buildroot
toolchain. To use alternative toolchain, you simply need to add change of
the following configuration options to your .config (or defconfig) file:
CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery under Windows
CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYL=y : CodeSourcery under Linux
CONFIG_ARMV7M_TOOLCHAIN_ATOLLIC=y : Atollic toolchain for Windos
CONFIG_ARMV7M_TOOLCHAIN_DEVKITARM=y : devkitARM under Windows
CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT=y : NuttX buildroot under Linux or Cygwin (default)
CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIL=y : Generic GCC ARM EABI toolchain for Linux
CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIW=y : Generic GCC ARM EABI toolchain for Windows
You may also have to modify the PATH in the setenv.h file if your
make cannot find the tools.
NOTE about Windows native toolchains
------------------------------------
There are basically three kinds of GCC toolchains that can be used:
1. A Linux native toolchain in a Linux environment,
2. The buildroot Cygwin tool chain built in the Cygwin environment,
3. A Windows native toolchain.
There are several limitations to using a Windows based toolchain (#3) in a
Cygwin environment. The three biggest are:
1. The Windows toolchain cannot follow Cygwin paths. Path conversions are
performed automatically in the Cygwin makefiles using the 'cygpath'
utility but you might easily find some new path problems. If so, check
out 'cygpath -w'
2. Windows toolchains cannot follow Cygwin symbolic links. Many symbolic
links are used in Nuttx (e.g., include/arch). The make system works
around these problems for the Windows tools by copying directories
instead of linking them. But this can also cause some confusion for
you: For example, you may edit a file in a "linked" directory and find
that your changes had no effect. That is because you are building the
copy of the file in the "fake" symbolic directory. If you use a
Windows toolchain, you should get in the habit of making like this:
make clean_context all
An alias in your .bashrc file might make that less painful.
3. Dependencies are not made when using Windows versions of the GCC. This
is because the dependencies are generated using Windows paths which do
not work with the Cygwin make.
MKDEP = $(TOPDIR)/tools/mknulldeps.sh
IDEs
^^^^
NuttX is built using command-line make. It can be used with an IDE, but some
effort will be required to create the project (There is a simple RIDE project
in the RIDE subdirectory).
Makefile Build
--------------
Under Eclipse, it is pretty easy to set up an "empty makefile project" and
simply use the NuttX makefile to build the system. That is almost for free
under Linux. Under Windows, you will need to set up the "Cygwin GCC" empty
makefile project in order to work with Windows (Google for "Eclipse Cygwin" -
there is a lot of help on the internet).
Native Build
------------
Here are a few tips before you start that effort:
1) Select the toolchain that you will be using in your .config file
2) Start the NuttX build at least one time from the Cygwin command line
before trying to create your project. This is necessary to create
certain auto-generated files and directories that will be needed.
3) Set up include pathes: You will need include/, arch/arm/src/sam34,
arch/arm/src/common, arch/arm/src/armv7-m, and sched/.
4) All assembly files need to have the definition option -D __ASSEMBLY__
on the command line.
Startup files will probably cause you some headaches. The NuttX startup file
is arch/arm/src/sam34/sam_vectors.S. You may need to build NuttX
one time from the Cygwin command line in order to obtain the pre-built
startup object needed by RIDE.
NuttX EABI "buildroot" Toolchain
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
A GNU GCC-based toolchain is assumed. The files */setenv.sh should
be modified to point to the correct path to the Cortex-M3 GCC toolchain (if
different from the default in your PATH variable).
If you have no Cortex-M3 toolchain, one can be downloaded from the NuttX
SourceForge download site (https://sourceforge.net/projects/nuttx/files/buildroot/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
1. You must have already configured Nuttx in <some-dir>/nuttx.
cd tools
./configure.sh sam4e-ek/<sub-dir>
2. Download the latest buildroot package into <some-dir>
3. unpack the buildroot tarball. The resulting directory may
have versioning information on it like buildroot-x.y.z. If so,
rename <some-dir>/buildroot-x.y.z to <some-dir>/buildroot.
4. cd <some-dir>/buildroot
5. cp configs/cortexm3-eabi-defconfig-4.6.3 .config
6. make oldconfig
7. make
8. Edit setenv.h, if necessary, so that the PATH variable includes
the path to the newly built binaries.
See the file configs/README.txt in the buildroot source tree. That has more
details PLUS some special instructions that you will need to follow if you are
building a Cortex-M3 toolchain for Cygwin under Windows.
NOTE: Unfortunately, the 4.6.3 EABI toolchain is not compatible with the
the NXFLAT tools. See the top-level TODO file (under "Binary loaders") for
more information about this problem. If you plan to use NXFLAT, please do not
use the GCC 4.6.3 EABI toochain; instead use the GCC 4.3.3 OABI toolchain.
See instructions below.
NuttX OABI "buildroot" Toolchain
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The older, OABI buildroot toolchain is also available. To use the OABI
toolchain:
1. When building the buildroot toolchain, either (1) modify the cortexm3-eabi-defconfig-4.6.3
configuration to use EABI (using 'make menuconfig'), or (2) use an exising OABI
configuration such as cortexm3-defconfig-4.3.3
2. Modify the Make.defs file to use the OABI conventions:
+CROSSDEV = arm-nuttx-elf-
+ARCHCPUFLAGS = -mtune=cortex-m3 -march=armv7-m -mfloat-abi=soft
+NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-gotoff.ld -no-check-sections
-CROSSDEV = arm-nuttx-eabi-
-ARCHCPUFLAGS = -mcpu=cortex-m3 -mthumb -mfloat-abi=soft
-NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-pcrel.ld -no-check-sections
NXFLAT Toolchain
^^^^^^^^^^^^^^^^
If you are *not* using the NuttX buildroot toolchain and you want to use
the NXFLAT tools, then you will still have to build a portion of the buildroot
tools -- just the NXFLAT tools. The buildroot with the NXFLAT tools can
be downloaded from the NuttX SourceForge download site
(https://sourceforge.net/projects/nuttx/files/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
1. You must have already configured Nuttx in <some-dir>/nuttx.
cd tools
./configure.sh sam4e-ek/<sub-dir>
2. Download the latest buildroot package into <some-dir>
3. unpack the buildroot tarball. The resulting directory may
have versioning information on it like buildroot-x.y.z. If so,
rename <some-dir>/buildroot-x.y.z to <some-dir>/buildroot.
4. cd <some-dir>/buildroot
5. cp configs/cortexm3-defconfig-nxflat .config
6. make oldconfig
7. make
8. Edit setenv.h, if necessary, so that the PATH variable includes
the path to the newly builtNXFLAT binaries.
Atmel Studio 6.1
^^^^^^^^^^^^^^^^
You can use Atmel Studio 6.1 to load and debug code.
- To load code into FLASH:
Tools menus: Tools -> Device Programming.
Configure the debugger and chip and you are in business.
- Debugging the NuttX Object File:
1) Rename object file from nutt to nuttx.elf. That is an extension that
will be recognized by the file menu.
2) Select the project name, the full path to the NuttX object (called
just nuttx with no extension), and chip. Take the time to resolve
all of the source file linkages or else you will not have source
level debug!
File menu: File -> Open -> Open object file for debugging
- Select nuttx.elf object file
- Select AT91SAM4E16
- Select files for symbols as desired
- Select debugger
3) Debug menu: Debug -> Start debugging and break
- This will reload the nuttx.elf file into FLASH
LEDs
^^^^
The SAM4E-EK board has three, user-controllable LEDs labelled D2 (blue),
D3 (amber), and D4 (green) on the board. Usage of these LEDs is defined
in include/board.h and src/up_leds.c. They are encoded as follows:
SYMBOL Meaning D3* D2 D4
------------------- ----------------------- ------- ------- -------
LED_STARTED NuttX has been started OFF OFF OFF
LED_HEAPALLOCATE Heap has been allocated OFF OFF ON
LED_IRQSENABLED Interrupts enabled OFF ON OFF
LED_STACKCREATED Idle stack created OFF ON ON
LED_INIRQ In an interrupt** N/C FLASH N/C
LED_SIGNAL In a signal handler*** N/C N/C FLASH
LED_ASSERTION An assertion failed FLASH N/C N/C
LED_PANIC The system has crashed FLASH N/C N/C
* If D2 and D4 are statically on, then NuttX probably failed to boot
and these LEDs will give you some indication of where the failure was
** The normal state is D3=OFF, D4=ON and D2 faintly glowing. This faint
glow is because of timer interrupts that result in the LED being
illuminated on a small proportion of the time.
*** D4 may also flicker normally if signals are processed.
Serial Console
^^^^^^^^^^^^^^
By default, all of these configurations use UART0 for the NuttX serial
console. UART0 corresponds to the DB-9 connector labelled "UART". This
is a male connector and will require a female-to-female, NUL modem cable
to connect to a PC.
An alternate is USART1 which connects to the other DB-9 connector labeled
"USART". USART1 is not enabled by default unless specifically noted
otherwise in the configuration description. A NUL modem cable must be
used with the port as well.
NOTE: One of the USART1 pins is shared with the audio CODEC. The audio
CODEC cannot be used of USART1 is enabled.
By default serial console is configured for 115000, 8-bit, 1 stop bit, and
no parity.
SAM4E-EK-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_CORTEXM3=y
CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory
CONFIG_ARCH_CHIP="sam34"
CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
chip:
CONFIG_ARCH_CHIP_SAM34
CONFIG_ARCH_CHIP_SAM3U
CONFIG_ARCH_CHIP_ATSAM3U4
CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD=sam4e-ek (for the SAM4E-EK development board)
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_SAM4EEK=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=0x00020000 (128Kb)
CONFIG_RAM_START - The start address of installed DRAM
CONFIG_RAM_START=0x20000000
CONFIG_ARCH_IRQPRIO - The SAM3U supports interrupt prioritization
CONFIG_ARCH_IRQPRIO=n
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:
CONFIG_SAM34_SPI0 - Serial Peripheral Interface 0 (SPI0)
CONFIG_SAM34_SPI1 - Serial Peripheral Interface 1 (SPI1)
CONFIG_SAM34_SSC - Synchronous Serial Controller (SSC)
CONFIG_SAM34_TC0 - Timer/Counter 0 (TC0)
CONFIG_SAM34_TC1 - Timer/Counter 1 (TC1)
CONFIG_SAM34_TC2 - Timer/Counter 2 (TC2)
CONFIG_SAM34_TC3 - Timer/Counter 3 (TC3)
CONFIG_SAM34_TC4 - Timer/Counter 4 (TC4)
CONFIG_SAM34_TC5 - Timer/Counter 5 (TC5)
CONFIG_SAM34_TC6 - Timer/Counter 6 (TC6)
CONFIG_SAM34_TC7 - Timer/Counter 7 (TC6)
CONFIG_SAM34_TC8 - Timer/Counter 6 (TC8)
CONFIG_SAM34_PWM - Pulse Width Modulation (PWM) Controller
CONFIG_SAM34_TWIM0 - Two-wire Master Interface 0 (TWIM0)
CONFIG_SAM34_TWIS0 - Two-wire Slave Interface 0 (TWIS0)
CONFIG_SAM34_TWIM1B - Two-wire Master Interface 1 (TWIM1)
CONFIG_SAM34_TWIS1 - Two-wire Slave Interface 1 (TWIS1)
CONFIG_SAM34_UART0 - UART 0
CONFIG_SAM34_UART1 - UART 1
CONFIG_SAM34_USART0 - USART 0
CONFIG_SAM34_USART1 - USART 1
CONFIG_SAM34_USART2 - USART 2
CONFIG_SAM34_USART3 - USART 3
CONFIG_SAM34_AFEC0 - Analog Front End 0
CONFIG_SAM34_AFEC1 - Analog Front End 1
CONFIG_SAM34_DACC - Digital-to-Analog Converter
CONFIG_SAM34_ACC - Analog Comparator
CONFIG_SAM34_EMAC - Ethernet MAC
CONFIG_SAM34_CAN0 - CAN 0
CONFIG_SAM34_CAN1 - CAN 1
CONFIG_SAM34_SMC - Static Memory Controller
CONFIG_SAM34_NAND - NAND support
CONFIG_SAM34_PDCA - Peripheral DMA controller
CONFIG_SAM34_DMAC - DMA controller
CONFIG_SAM34_UDP - USB 2.0 Full-Speed device
CONFIG_SAM34_CHIPID - Chip ID
CONFIG_SAM34_RTC - Real Time Clock
CONFIG_SAM34_RTT - Real Time Timer
CONFIG_SAM34_WDT - Watchdog Timer
CONFIG_SAM34_EIC - Interrupt controller
CONFIG_SAM34_HSMCI - High Speed Multimedia Card Interface
Some subsystems can be configured to operate in different ways. The drivers
need to know how to configure the subsystem.
CONFIG_GPIOA_IRQ
CONFIG_GPIOB_IRQ
CONFIG_GPIOC_IRQ
CONFIG_GPIOD_IRQ
CONFIG_GPIOE_IRQ
CONFIG_GPIOF_IRQ
CONFIG_GPIOG_IRQ
CONFIG_GPIOH_IRQ
CONFIG_GPIOJ_IRQ
CONFIG_GPIOK_IRQ
CONFIG_GPIOL_IRQ
CONFIG_GPIOM_IRQ
CONFIG_GPION_IRQ
CONFIG_GPIOP_IRQ
CONFIG_GPIOQ_IRQ
CONFIG_USART0_ISUART
CONFIG_USART1_ISUART
CONFIG_USART2_ISUART
CONFIG_USART3_ISUART
SAM3U specific device driver settings
CONFIG_U[S]ARTn_SERIAL_CONSOLE - selects the USARTn (n=0,1,2,3) 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
LCD Options. Other than the standard LCD configuration options
(see configs/README.txt), the SAM4E-EK driver also supports:
CONFIG_LCD_PORTRAIT - Present the display in the standard 240x320
"Portrait" orientation. Default: The display is rotated to
support a 320x240 "Landscape" orientation.
Configurations
^^^^^^^^^^^^^^
Information Common to All Configurations
----------------------------------------
Each SAM4E-EK configuration is maintained in a sub-directory and
can be selected as follow:
cd tools
./configure.sh sam4e-ek/<subdir>
cd -
. ./setenv.sh
Before sourcing the setenv.sh file above, you should examine it and perform
edits as necessary so that BUILDROOT_BIN is the correct path to the directory
than holds your toolchain binaries.
And then build NuttX by simply typing the following. At the conclusion of
the make, the nuttx binary will reside in an ELF file called, simply, nuttx.
make
The <subdir> that is provided above as an argument to the tools/configure.sh
must be is one of the following.
NOTES:
1. These configurations use the mconf-based configuration tool. To
change any of these configurations using that tool, you should:
a. Build and install the kconfig-mconf tool. See nuttx/README.txt
and misc/tools/
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. Unless stated otherwise, all configurations generate console
output on UART0 (J3).
3. Unless otherwise stated, the configurations are setup for
Linux (or any other POSIX environment like Cygwin under Windows):
Build Setup:
CONFIG_HOST_LINUX=y : Linux or other POSIX environment
4. All of these configurations use the older, OABI, buildroot toolchain
(unless stated otherwise in the description of the configuration). That
toolchain selection can easily be reconfigured using 'make menuconfig'.
Here are the relevant current settings:
Build Setup:
CONFIG_HOST_LINUX=y : Linux or other pure POSIX invironment
: (including Cygwin)
System Type -> Toolchain:
CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT=y : Buildroot toolchain
CONFIG_ARMV7M_OABI_TOOLCHAIN=y : Older, OABI toolchain
If you want to use the Atmel GCC toolchain, for example, here are the
steps to do so:
Build Setup:
CONFIG_HOST_WINDOWS=y : Windows
CONFIG_HOST_CYGWIN=y : Using Cygwin or other POSIX environment
System Type -> Toolchain:
CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIW=y : General GCC EABI toolchain under windows
Library Routines ->
CONFIG_CXX_NEWLONG=n : size_t is an unsigned int, not long
This re-configuration should be done before making NuttX or else the
subsequent 'make' will fail. If you have already attempted building
NuttX then you will have to 1) 'make distclean' to remove the old
configuration, 2) 'cd tools; ./configure.sh sam4e-ek/ksnh' to start
with a fresh configuration, and 3) perform the configuration changes
above.
Also, make sure that your PATH variable has the new path to your
Atmel tools. Try 'which arm-none-eabi-gcc' to make sure that you
are selecting the right tool. setenv.sh is available for you to
use to set or PATH variable. The path in the that file may not,
however, be correct for your installation.
See also the "NOTE about Windows native toolchains" in the section call
"GNU Toolchain Options" above.
Configuration sub-directories
-----------------------------
nsh:
Configures the NuttShell (nsh) located at examples/nsh. The
Configuration enables both the serial and telnetd NSH interfaces.
NOTES:
1. NSH built-in applications are supported. However, there are
no built-in applications built with the default configuration.
Binary Formats:
CONFIG_BUILTIN=y : Enable support for built-in programs
Applicaton Configuration:
CONFIG_NSH_BUILTIN_APPS=y : Enable starting apps from NSH command line
2. This configuration has been used for verifying the touchscreen on
on the SAM4E-EK LCD. With these modifications, you can include the
touchscreen test program at apps/examples/touchscreen as an NSH built-in
application. You can enable the touchscreen and test by modifying the
default configuration in the following ways:
Device Drivers
CONFIG_SPI=y : Enable SPI support
CONFIG_SPI_EXCHANGE=y : The exchange() method is supported
CONFIG_SPI_OWNBUS=y : Smaller code if this is the only SPI device
CONFIG_INPUT=y : Enable support for input devices
CONFIG_INPUT_ADS7843E=y : Enable support for the XPT2046
CONFIG_ADS7843E_SPIDEV=2 : Use SPI CS 2 for communication
CONFIG_ADS7843E_SPIMODE=0 : Use SPI mode 0
CONFIG_ADS7843E_FREQUENCY=1000000 : SPI BAUD 1MHz
CONFIG_ADS7843E_SWAPXY=y : If landscpe orientation
CONFIG_ADS7843E_THRESHX=51 : These will probably need to be tuned
CONFIG_ADS7843E_THRESHY=39
System Type -> Peripherals:
CONFIG_SAM34_SPI0=y : Enable support for SPI
System Type:
CONFIG_GPIO_IRQ=y : GPIO interrupt support
CONFIG_GPIOA_IRQ=y : Enable GPIO interrupts from port A
RTOS Features:
CONFIG_DISABLE_SIGNALS=n : Signals are required
Library Support:
CONFIG_SCHED_WORKQUEUE=y : Work queue support required
Applicaton Configuration:
CONFIG_EXAMPLES_TOUCHSCREEN=y : Enable the touchscreen built-int test
Defaults should be okay for related touchscreen settings. Touchscreen
debug output on UART0 can be enabled with:
Build Setup:
CONFIG_DEBUG=y : Enable debug features
CONFIG_DEBUG_VERBOSE=y : Enable verbose debug output
CONFIG_DEBUG_INPUT=y : Enable debug output from input devices
3. Enabling HSMCI support. The SAM3U-KE provides a an SD memory card
slot. Support for the SD slot can be enabled with the following
settings:
System Type->ATSAM3/4 Peripheral Support
CONFIG_SAM34_HSMCI=y : Enable HSMCI support
CONFIG_SAM34_DMAC=y : DMAC support is needed by HSMCI
System Type
CONFIG_SAM34_GPIO_IRQ=y : PIO interrupts needed
CONFIG_SAM34_GPIOA_IRQ=y : Card detect pin is on PIOA
Device Drivers -> MMC/SD Driver Support
CONFIG_MMCSD=y : Enable MMC/SD support
CONFIG_MMSCD_NSLOTS=1 : One slot per driver instance
CONFIG_MMCSD_HAVECARDDETECT=y : Supports card-detect PIOs
CONFIG_MMCSD_SDIO=y : SDIO-based MMC/SD support
CONFIG_SDIO_DMA=y : Use SDIO DMA
CONFIG_SDIO_BLOCKSETUP=y : Needs to know block sizes
Library Routines
CONFIG_SCHED_WORKQUEUE=y : Driver needs work queue support
Application Configuration -> NSH Library
CONFIG_NSH_ARCHINIT=y : NSH board-initialization
STATUS:
2013-6-28: The touchscreen is functional.
2013-6-29: Hmmm... but there appear to be conditions when the
touchscreen driver locks up. Looks like some issue with
managing the interrupts.
2013-6-30: Those lock-ups appear to be due to poorly placed
debug output statements. If you do not enable debug output,
the touchscreen is rock-solid.
2013-8-10: Added the comments above above enabling HSMCI memory
card support and verified that the configuration builds without
error. However, that configuration has not yet been tested (and
is may even be incomplete).
