replace *(.init_array .init_array.*) with KEEP(*(.init_array .init_array.*)).
The KEEP statement within a linker script will instruct the linker to keep the specified section, even if no symbols inside it are referenced. This statement is used within the SECTIONS section of the linker script. This becomes relevant when garbage collection is performed at link time, enabled by passing the --gc-sections switch to the linker. The KEEP statement instructs the linker to use the specified section as a root node when creating a dependency graph, looking for unused sections. Essentially forcing the section to be marked as used.
Signed-off-by: cuiziwei <cuiziwei@xiaomi.com>
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README
======
This README discusses issues unique to NuttX configurations for the ST
Nucleo-l432kc board from ST Micro. See
http://www.st.com/nucleo-l432kc
NucleoL432KC:
Microprocessor: 32-bit ARM Cortex M4 at 80MHz STM32L432KCU6
Memory: 256 KB Flash and 64 KB SRAM
ADC: 1×12-bit, 5 MSPS A/D converter: up to 10 channels
DMA: 16-stream DMA controllers with FIFOs and burst support
Timers: Up to 11 timers: up to five 16-bit, one 32-bit, two low-power
16 bit timers, two watchdog timers, and a SysTick timer
GPIO: Up to 26 I/O ports with interrupt capability, most 5v tolerant
I2C: Up to 2 × I2C interfaces
USARTs: Up to 3 USARTs, 2 UARTs, 1 LPUART
SPIs: Up to 2 SPIs
SAIs: 1 dual-channel audio interface
CAN interface
QSPI interface
USB: USB 2.0 full-speed device/host/OTG controller with on-chip PHY
CRC calculation unit
RTC
Board features:
Peripherals: 1 led
Debug: Serial wire debug and JTAG interfaces via on-board micro-usb stlink v2.1
Expansion I/F Arduino Nano Headers
Uses a STM32F103 to provide a ST-Link for programming, debug similar to the
OpenOcd FTDI function - USB to JTAG front-end.
See http://mbed.org/platforms/ST-Nucleo-L432KC for more
information about these boards.
Contents
========
- Nucleo-32 Boards
- Development Environment
- GNU Toolchain Options
- IDEs
- NuttX EABI "buildroot" Toolchain
- NXFLAT Toolchain
- Hardware
- Button
- LED
- USARTs and Serial Consoles
- QFN32
- mbed
- SPI Flash support
- Configurations
Nucleo-32 Boards
================
The Nucleo-L432KC is a member of the Nucleo-64 board family. The Nucleo-64
is a standard board for use with several STM32 parts in the LQFP64 package.
Variants include
Order code Targeted STM32
------------- --------------
NUCLEO-F031K6 STM32F031K6T6
NUCLEO-F042K6 STM32F042K6T6
NUCLEO-F303K8 STM32F303K8T6
NUCLEO-L011K4 STM32L011K4T6
NUCLEO-L031K6 STM32L031K6T6
NUCLEO-L432KC STM32L432KCU6
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.
GNU Toolchain Options
=====================
Toolchain Configurations
------------------------
The NuttX make system has been modified to support the following different
toolchain options.
1. The NuttX buildroot Toolchain (see below), or
2. Any generic arm-none-eabi GNU toolchain.
All testing has been conducted using the NuttX CodeSourcery toolchain. To use
a different toolchain, you simply need to modify the configuration. As an
example:
CONFIG_ARM_TOOLCHAIN_GNU_EABI : Generic arm-none-eabi toolchain
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.
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).
Using Sourcery CodeBench from http://www.mentor.com/embedded-software/sourcery-tools/sourcery-codebench/overview
Download and install the latest version (as of this writing it was
sourceryg++-2013.05-64-arm-none-eabi)
Import the project from git.
File->import->Git-URI, then import a Exiting code as a Makefile progject
from the working directory the git clone was done to.
Select the Sourcery CodeBench for ARM EABI. N.B. You must do one command line
build, before the make will work in CodeBench.
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 paths: You will need include/, arch/arm/src/stm32,
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/stm32/stm32_vectors.S. With RIDE, I have 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 PATH environment variable 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
Bitbucket download site (https://bitbucket.org/nuttx/buildroot/downloads/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
1. You must have already configured NuttX in <some-dir>/nuttx.
$ tools/configure.sh nucleo-l432kc:nsh
$ make qconfig
$ V=1 make context all 2>&1 | tee mout
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 boards/cortexm3-eabi-defconfig-4.6.3 .config
6. make oldconfig
7. make
8. Make sure that the PATH variable includes the path to the newly built
binaries.
See the file boards/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 toolchain; instead use the GCC 4.3.3 EABI toolchain.
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 Bitbucket download site
(https://bitbucket.org/nuttx/nuttx/downloads/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
1. You must have already configured NuttX in <some-dir>/nuttx.
tools/configure.sh lpcxpresso-lpc1768:<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 boards/cortexm3-defconfig-nxflat .config
6. make oldconfig
7. make
8. Make sure that the PATH variable includes the path to the newly built
NXFLAT binaries.
mbed
====
The Nucleo-L432KC includes boot loader from mbed:
https://mbed.org/handbook/Homepage
Using the mbed loader:
1. Connect the Nucleo-L432kc to the host PC using the USB connector.
2. A new file system will appear called NUCLEO; open it with Windows
Explorer (assuming that you are using Windows).
3. Drag and drop nuttx.bin into the MBED window. This will load the
nuttx.bin binary into the Nucleo-L432kc. The NUCLEO window will
close then re-open and the Nucleo-L432KC will be running the new code.
Hardware
========
LEDs
----
The Nucleo L432KC provides a single user LED, LD3. LD3
is the green LED connected to Arduino signal D13 corresponding to MCU I/O
PB3 (pin 26).
- When the I/O is HIGH value, the LED is on.
- When the I/O is LOW, the LED is off.
These LEDs are 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/sam_leds.c. The LEDs are used to encode OS-related
events as follows when the LED is available:
SYMBOL Meaning LD3
------------------- ----------------------- -----------
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 No change
LED_SIGNAL In a signal handler No change
LED_ASSERTION An assertion failed No change
LED_PANIC The system has crashed Blinking
LED_IDLE MCU is is sleep mode Not used
Thus if LD3, NuttX has successfully booted and is, apparently, running
normally. If LD3 is flashing at approximately 2Hz, then a fatal error
has been detected and the system has halted.
Serial Consoles
===============
USART1
------
Pins and Connectors:
RXD: PA11 CN10 pin 14
PB7 CN7 pin 21
TXD: PA10 CN9 pin 3, CN10 pin 33
PB6 CN5 pin 3, CN10 pin 17
NOTE: You may need to edit the include/board.h to select different USART1
pin selections.
TTL to RS-232 converter connection:
Nucleo CN10 STM32L432KC
----------- ------------
Pin 21 PA9 USART1_RX *Warning you make need to reverse RX/TX on
Pin 33 PA10 USART1_TX some RS-232 converters
Pin 20 GND
Pin 8 U5V
To configure USART1 as the console:
CONFIG_STM32_USART1=y
CONFIG_USART1_SERIALDRIVER=y
CONFIG_USART1_SERIAL_CONSOLE=y
CONFIG_USART1_RXBUFSIZE=256
CONFIG_USART1_TXBUFSIZE=256
CONFIG_USART1_BAUD=115200
CONFIG_USART1_BITS=8
CONFIG_USART1_PARITY=0
CONFIG_USART1_2STOP=0
USART2
-----
Pins and Connectors:
RXD: PA3 CN9 pin 1 (See SB13, 14, 62, 63). CN10 pin 37
PD6
TXD: PA2 CN9 pin 2(See SB13, 14, 62, 63). CN10 pin 35
PD5
UART2 is the default in all of these configurations.
TTL to RS-232 converter connection:
Nucleo CN9 STM32L432KC
----------- ------------
Pin 1 PA3 USART2_RX *Warning you make need to reverse RX/TX on
Pin 2 PA2 USART2_TX some RS-232 converters
Solder Bridges. This configuration requires:
- SB62 and SB63 Closed: PA2 and PA3 on STM32 MCU are connected to D1 and D0
(pin 7 and pin 8) on Arduino connector CN9 and ST Morpho connector CN10
as USART signals. Thus SB13 and SB14 should be OFF.
- SB13 and SB14 Open: PA2 and PA3 on STM32F103C8T6 (ST-LINK MCU) are
disconnected to PA3 and PA2 on STM32 MCU.
To configure USART2 as the console:
CONFIG_STM32_USART2=y
CONFIG_USART2_SERIALDRIVER=y
CONFIG_USART2_SERIAL_CONSOLE=y
CONFIG_USART2_RXBUFSIZE=256
CONFIG_USART2_TXBUFSIZE=256
CONFIG_USART2_BAUD=115200
CONFIG_USART2_BITS=8
CONFIG_USART2_PARITY=0
CONFIG_USART2_2STOP=0
Virtual COM Port
----------------
Yet another option is to use UART2 and the USB virtual COM port. This
option may be more convenient for long term development, but is painful
to use during board bring-up.
Solder Bridges. This configuration requires:
- SB62 and SB63 Open: PA2 and PA3 on STM32 MCU are disconnected to D1
and D0 (pin 7 and pin 8) on Arduino connector CN9 and ST Morpho
connector CN10.
- SB13 and SB14 Closed: PA2 and PA3 on STM32F103C8T6 (ST-LINK MCU) are
connected to PA3 and PA2 on STM32 MCU to have USART communication
between them. Thus SB61, SB62 and SB63 should be OFF.
Configuring USART2 is the same as given above.
Question: What BAUD should be configure to interface with the Virtual
COM port? 115200 8N1?
Default
-------
As shipped, SB62 and SB63 are open and SB13 and SB14 closed, so the
virtual COM port is enabled.
SPI Flash support:
=====================
We can use an external SPI Serial Flash with nucleo-l432kc board. In this
case we tested with AT45DB081D (8Mbit = 1MiB).
You can connect the AT45DB081D memory in the nucleo-l432kc board this way:
--------------------------------
| Memory nucleo-l432kc |
|------------------------------|
| SI ---> D11 (PB5) |
| SCK ---> D13 (PB3) |
| /RESET ---> 3V3 |
| /CS ---> D10 (PA11) |
| /WP ---> 3V3 |
| VCC ---> 3V3 |
| GND ---> GND |
| SO ---> D12 (PB4) |
--------------------------------
You can start with default "nucleo-l432kc/nsh" configuration option and
enable/disable these options using "make menuconfig" :
System Type --->
STM32L4 Peripheral Support --->
[*] SPI1
Device Drivers --->
-*- Memory Technology Device (MTD) Support --->
-*- SPI-based AT45DB flash
(1000000) AT45DB Frequency
File Systems --->
[*] NXFFS file system
Then after compiling and flashing the file nuttx.bin you can test the flash
this way:
nsh> ls /mnt
/mnt:
at45db/
nsh> echo "Testing" > /mnt/at45db/file.txt
nsh> ls /mnt/at45db
/mnt/at45db:
file.txt
nsh> cat /mnt/at45db/file.txt
Testing
nsh>
Configurations
==============
nsh:
---------
Configures the NuttShell (nsh) located at apps/examples/nsh for the
Nucleo-L432KC board. 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 ARM EABI toolchain
for Linux. That can easily be reconfigured, of course.
CONFIG_HOST_LINUX=y : Builds under Linux
CONFIG_ARM_TOOLCHAIN_GNU_EABI=y : GNU EABI toolchain for Linux
3. Although the default console is USART2 (which would correspond to
the Virtual COM port) I have done all testing with the console
device configured for USART1 (see instruction above under "Serial
Consoles). I have been using a TTL-to-RS-232 converter connected
as shown below:
Nucleo CN10 STM32L432KC
----------- ------------
Pin 21 PA9 USART1_RX *Warning you make need to reverse RX/TX on
Pin 33 PA10 USART1_TX some RS-232 converters
Pin 20 GND
Pin 8 U5V
spwm
----
Configures the sinusoidal PWM (SPWM) example which presents a simple use case
of the STM32L4 PWM lower-half driver without generic upper-half PWM logic.
It uses TIM1 to generate PWM and TIM6 to change waveform samples
At the moment, the waveform parameters are hardcoded, but it should be easy to
modify this example and make it more functional.
25eb09c3bb