README
======
This README file describes the port of NuttX to the SAMA5D2 Xplained Ulta
development board. This board features the Atmel SAMA5D27 microprocessor.
See http://www.atmel.com for further information.
Contents
========
- STATUS
- Loading Code into SRAM with J-Link
- DRAMBOOT, AT25BOOT, SRAMBOOT
- Running NuttX from SDRAM
- Buttons and LEDs
- Serial Console
- SAMA5D2-XULT Configuration Options
- Configurations
STATUS
======
1. Most of this document is a partially corrected clone of the SAMA5D4-EK
README.txt and still contains errors and inconsistencies.
2. Coding is complete for the basic SAMA5D2-XULT NSH configuration, but
is completely untested as of this writing (2015-09-15). The primary
issue is that I have not yet determine how to load and test code.
Loading Code into SRAM with J-Link
==================================
REVISIT: Unverified, cloned text from the SAMA5D4-EK README.txt
Loading code with the Segger tools and GDB
------------------------------------------
1) Change directories into the directory where you built NuttX.
2) Start the GDB server and wait until it is ready to accept GDB
connections.
3) Then run GDB like this:
$ arm-none-eabi-gdb
(gdb) target remote localhost:2331
(gdb) mon reset
(gdb) load nuttx
(gdb) ... start debugging ...
Loading code using J-Link Commander
----------------------------------
J-Link> r
J-Link> loadbin <file> <address>
J-Link> setpc <address of __start>
J-Link> ... start debugging ...
DRAMBOOT, AT25BOOT, SRAMBOOT
----------------------------
See also boards/arm/sama5/sama5d4-xult/README.txt for a description of the DRAMBOOT
program. This is a tiny version of NuttX that can run out of internal
SRAM. If you put this program on the HSMCI1 microSD card as boot.bin, then
it will boot on power up and you can download NuttX directly into DRAM by
sending the nuttx.hex file over the serial connection.
The boards/arm/sama5/sama5d4-xult/README.txt also describes variants AT25BOOT and
SRAMBOOT. This have not yet been ported to the SAMA5D2-XULT, but are
available if they are useful too you.
Running NuttX from SDRAM
========================
REVISIT: Unverified, cloned text from the SAMA5D4-EK README.txt
NuttX may be executed from SDRAM. But this case means that the NuttX
binary must reside on some other media (typically NAND FLASH, Serial
FLASH) or transferred over some interface (perhaps a UARt or even a
TFTP server). In these cases, an intermediate bootloader such as U-Boot
or Barebox must be used to configure the SAMA5D2 clocks and SDRAM and
then to copy the NuttX binary into SDRAM.
- NuttX Configuration
- Boot sequence
- NAND FLASH Memory Map
- Programming the AT91Boostrap Binary
- Programming U-Boot
- Load NuttX with U-Boot on AT91 boards
TODO: Some drivers may require some adjustments to run from SDRAM. That
is because in this case macros like BOARD_MCK_FREQUENCY are not constants
but are instead function calls: The MCK clock frequency is not known in
advance but instead has to be calculated from the bootloader PLL configuration.
See the TODO list at the end of this file for further information.
NuttX Configuration
-------------------
In order to run from SDRAM, NuttX must be built at origin 0x20008000 in
SDRAM (skipping over SDRAM memory used by the bootloader). The following
configuration option is required:
CONFIG_SAMA5_BOOT_SDRAM=y
CONFIG_BOOT_RUNFROMSDRAM=y
These options tell the NuttX code that it will be booting and running from
SDRAM. In this case, the start-logic will do to things: (1) it will not
configure the SAMA5D2 clocking. Rather, it will use the clock configuration
as set up by the bootloader. And (2) it will not attempt to configure the
SDRAM. Since NuttX is already running from SDRAM, it must accept the SDRAM
configuration as set up by the bootloader.
Boot sequence
-------------
Reference: http://www.at91.com/linux4sam/bin/view/Linux4SAM/GettingStarted
Several pieces of software are involved to boot a Nutt5X into SDRAM. First
is the primary bootloader in ROM which is in charge to check if a valid
application is present on supported media (NOR FLASH, Serial DataFlash,
NAND FLASH, SD card).
The boot sequence of linux4SAM is done in several steps :
1. The ROM bootloader checks if a valid application is present in FLASH
and if it is the case downloads it into internal SRAM. This program
is usually a second level bootloader called AT91BootStrap.
2. AT91Bootstrap is the second level bootloader. It is in charge of the
hardware configuration. It downloads U-Boot / Barebox binary from
FLASH to SDRAM / DDRAM and starts the third level bootloader
(U-Boot / Barebox)
(see http://www.at91.com/linux4sam/bin/view/Linux4SAM/AT91Bootstrap).
3. The third level bootloader is either U-Boot or Barebox. The third
level bootloader is in charge of downloading NuttX binary from FLASH,
network, SD card, etc. It then starts NuttX.
4. Then NuttX runs from SDRAM
NAND FLASH Memory Map
---------------------
Reference: http://www.at91.com/linux4sam/bin/view/Linux4SAM/GettingStarted
0x0000:0000 - 0x0003:ffff: AT91BootStrap
0x0004:0000 - 0x000b:ffff: U-Boot
0x000c:0000 - 0x000f:ffff: U-Boot environment
0x0010:0000 - 0x0017:ffff: U-Boot environment redundant
0x0018:0000 - 0x001f:ffff: Device tree (DTB)
0x0020:0000 - 0x007f:ffff: NuttX
0x0080:0000 - end: Available for use as a NAND file system
Programming the AT91Boostrap Binary
-----------------------------------
Reference: http://www.at91.com/linux4sam/bin/view/Linux4SAM/AT91Bootstrap
This section describes how to program AT91Bootstrap binary into the boot
media with SAM-BA tool using NandFlash as boot media.
1. Get AT91BootStrap binaries. Build instructions are available here:
http://www.at91.com/linux4sam/bin/view/Linux4SAM/AT91Bootstrap#Build_AT91Bootstrap_from_sources
A pre-built AT91BootStrap binary is available here:
ftp://www.at91.com/pub/at91bootstrap/AT91Bootstrap3.6.1/sama5d3_xplained-nandflashboot-uboot-3.6.1.bin
2. Start the SAM-BA GUI Application:
- Connect the USB Device interface to your host machine using the USB
Device Cable.
- Make sure that the chip can execute the SAM-BA Monitor.
- Start SAM-BA GUI application.
- Select the board in the drop-down menu and choose the USB connection.
3. In the SAM-BA GUI Application:
- Choose the "NandFlash" tab in the SAM-BA GUI interface.
- Initialize the NandFlash by choosing the "Enable NandFlash" action in
the Scripts rolling menu, then press "Execute" button.
- Erase the NandFlash device by choosing the "Erase All" action, then
press "Execute" button.
- Enable the PMECC by choosing the "Enable OS PMECC parameters" action,
then press "Execute" button.
PMECC
Number of sectors per page: 4
Spare Size: 64
Number of ECC bits required: 4
Size of the ECC sector: 512
ECC offset: 36
- Choose "Send Boot File" action, then press Execute button to select the
at91bootstrap binary file and to program the binary to the NandFlash.
- Close SAM-BA, remove the USB Device cable.
Programming U-Boot
-------------------
Reference http://www.at91.com/linux4sam/bin/view/Linux4SAM/U-Boot
1. Get U-Boot Binaries. Build instructions are available here:
http://www.at91.com/linux4sam/bin/view/Linux4SAM/U-Boot#Build_U_Boot_from_sources
A pre-Built binary image is available here:
ftp://www.at91.com/pub/uboot/u-boot-v2013.07/u-boot-sama5d3_xplained-v2013.07-at91-r1.bin
2. Start the SAM-BA GUI Application:
- Connect the USB Device interface to your host machine using the USB
Device Cable.
- Make sure that the chip can execute the SAM-BA Monitor.
- Start SAM-BA GUI application.
- Select the board in the drop-down menu and choose the USB connection.
3. In the SAM-BA GUI Application:
- Choose the NandFlash tab in the SAM-BA GUI interface.
- Initialize the NandFlash by choosing the "Enable NandFlash" action in
the Scripts rolling menu, then press Execute button.
- Enable the PMECC by choosing the "Enable OS PMECC parameters" action,
then press Execute button.
PMECC
Number of sectors per page: 4
Spare Size: 64
Number of ECC bits required: 4
Size of the ECC sector: 512
ECC offset: 36
- Press the "Send File Name" Browse button
- Choose u-boot.bin binary file and press Open
- Enter the proper address on media in the Address text field:
0x00040000
- Press the "Send File" button
- Close SAM-BA, remove the USB Device cable.
You should now be able to interrupt with U-Boot via the DBGU interface.
Load NuttX with U-Boot on AT91 boards
-------------------------------------
Reference http://www.at91.com/linux4sam/bin/view/Linux4SAM/U-Boot
Preparing NuttX image
U-Boot does not support normal binary images. Instead you have to
create an uImage file with the mkimage tool which encapsulates kernel
image with header information, CRC32 checksum, etc.
mkimage comes in source code with U-Boot distribution and it is built
during U-Boot compilation (u-boot-source-dir/tools/mkimage). There
are also sites where you can download pre-built mkimage binaries. For
example: http://www.trimslice.com/wiki/index.php/U-Boot_images
See the U-Boot README file for more information. More information is
also available in the mkimage man page (for example,
http://linux.die.net/man/1/mkimage).
Command to generate an uncompressed uImage file (4) :
mkimage -A arm -O linux -C none -T kernel -a 20008000 -e 20008000 \
-n nuttx -d nuttx.bin uImage
Where:
-A arm: Set architecture to ARM
-O linux: Select operating system. bootm command of u-boot changes
boot method by os type.
-T kernel: Set image type.
-C none: Set compression type.
-a 20008000: Set load address.
-e 20008000: Set entry point.
-n nuttx: Set image name.
-d nuttx.bin: Use image data from nuttx.bin.
This will generate a binary called uImage. If you have the path to
mkimage in your PATH variable, then you can automatically build the
uImage file by adding the following to your .config file:
CONFIG_RAW_BINARY=y
CONFIG_UBOOT_UIMAGE=y
CONFIG_UIMAGE_LOAD_ADDRESS=0x20008000
CONFIG_UIMAGE_ENTRY_POINT=0x20008040
The uImage file can them be loaded into memory from a variety of sources
(serial, SD card, JFFS2 on NAND, TFTP).
STATUS:
2014-4-1: So far, I am unable to get U-Boot to execute the uImage
file. I get the following error messages (in this case
trying to load from an SD card):
U-Boot> fatload mmc 0 0x22000000 uimage
reading uimage
97744 bytes read in 21 ms (4.4 MiB/s)
U-Boot> bootm 0x22000000
## Booting kernel from Legacy Image at 0x22000000 ...
Image Name: nuttx
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 97680 Bytes = 95.4 KiB
Load Address: 20008000
Entry Point: 20008040
Verifying Checksum ... OK
XIP Kernel Image ... OK
FDT and ATAGS support not compiled in - hanging
### ERROR ### Please RESET the board ###
This, however, appears to be a usable workaround:
U-Boot> fatload mmc 0 0x20008000 nuttx.bin
mci: setting clock 257812 Hz, block size 512
mci: setting clock 257812 Hz, block size 512
mci: setting clock 257812 Hz, block size 512
gen_atmel_mci: CMDR 00001048 ( 8) ARGR 000001aa (SR: 0c100025) Command Time Out
mci: setting clock 257812 Hz, block size 512
mci: setting clock 22000000 Hz, block size 512
reading nuttx.bin
108076 bytes read in 23 ms (4.5 MiB/s)
U-Boot> go 0x20008040
## Starting application at 0x20008040 ...
NuttShell (NSH) NuttX-7.2
nsh>
Loading through network
On a development system, it is useful to get the kernel and root file
system through the network. U-Boot provides support for loading
binaries from a remote host on the network using the TFTP protocol.
To manage to use TFTP with U-Boot, you will have to configure a TFTP
server on your host machine. Check your distribution manual or Internet
resources to configure a Linux or Windows TFTP server on your host:
- U-Boot documentation on a Linux host:
http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.6.
- Another TFTP configuration reference:
http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch16_:_Telnet%2C_TFTP%2C_and_xinetd#TFTP
On the U-Boot side, you will have to setup the networking parameters:
1. Setup an Ethernet address (MAC address)
Check this U-Boot network BuildRootFAQ entry to choose a proper MAC
address: http://www.denx.de/wiki/DULG/EthernetDoesNotWork
setenv ethaddr 00:e0:de:ad:be:ef
2. Setup IP parameters:
The board ip address
setenv ipaddr 10.0.0.2
The server ip address where the TFTP server is running
setenv serverip 10.0.0.1
3. saving Environment to flash
saveenv
4. If Ethernet Phy has not been detected during former bootup, reset
the board to reload U-Boot : the Ethernet address and Phy
initialization shall be ok, now
5. Download the NuttX uImage and the root file system to a ram location
using the U-Boot tftp command (Cf. U-Boot script capability chapter).
6. Launch NuttX issuing a bootm or boot command.
If the board has both emac and gmac, you can use following to choose
which one to use:
setenv ethact macb0,gmacb0
setenv ethprime gmacb0
STATUS:
2014-3-30: These instructions were adapted from the Linux4SAM website
but have not yet been used.
Using JTAG
----------
This description assumes that you have a JTAG debugger such as Segger
J-Link connected to the SAMA5D3-Xplained.
1. Start the GDB server
2. Start GDB
3. Use the 'target remote localhost:xxxx' command to attach to the GDG
server
4. Do 'mon reset' then 'mon go' to start the internal boot loader (maybe
U-Boot).
5. Let the boot loader run until it completes SDRAM initialization, then
do 'mon halt'.
6. Now you have SDRAM initialized and you use 'load nuttx' to load the
ELF file into SDRAM.
7. Use 'file nuttx' to load symbols
8. Set the PC to the NuttX entry point 'mon pc 0x20008040' and start
nuttx using 'mon go'.
Buttons and LEDs
================
Buttons
-------
A single button, PB_USER1 (PB6), is available on the SAMA5D2-XULT
------------------------------ ------------------- -------------------------
SAMA5D2 PIO SIGNAL USAGE
------------------------------ ------------------- -------------------------
PB6 USER_PB_PB6 PB_USER push button
------------------------------ ------------------- -------------------------
Closing PB_USER will bring PB6 to ground so 1) PB6 should have a weak pull-up,
and 2) when PB_USER is pressed, a low value will be senses.
Support for pollable buttons is enabled with:
CONFIG_ARCH_BUTTONS=y
For interrupt driven buttons, add:
CONFIG_ARCH_IRQBUTTONS=y
Program interfaces for button access are described in nuttx/include/nuttx/arch.h
There is an example that can be enabled to test button interrupts. That
example is enabled like:
CONFIG_EXAMPLES_BUTTONS=y
CONFIG_EXAMPLES_BUTTONS_MAX=0
CONFIG_EXAMPLES_BUTTONS_MIN=0
CONFIG_EXAMPLES_BUTTONS_NAME0="PB_USER"
CONFIG_EXAMPLES_IRQBUTTONS_MAX=0
CONFIG_EXAMPLES_IRQBUTTONS_MIN=0
LEDs
----
There is an RGB LED on board the SAMA5D2-XULT. The RED component is driven by
the SDHC_CD pin (PA13) and so will not be used. The LEDs are provided VDD_LED
and so bringing the LED low will will illuminated the LED.
------------------------------ ------------------- -------------------------
SAMA5D2 PIO SIGNAL USAGE
------------------------------ ------------------- -------------------------
PA13 SDHC_CD_PA13 Red LED
PB5 LED_GREEN_PB5 Green LED
PB0 LED_BLUE_PB0 Blue LED
------------------------------ ------------------- -------------------------
When CONFIG_ARCH_LEDS is defined in the NuttX configuration, NuttX will
control the Green LED (only)as follows:
SYMBOL Meaning Green LED
------------------- ----------------------- ---------
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 if the Green LED is statically on, NuttX has successfully booted and
is, apparently, running normally. If LED is flashing at approximately
2Hz, then a fatal error has been detected and the system has halted.
Serial Console
==============
DEBUG / DBGU Port (J1). There is a TTL serial connection available on
pins 2 and 3 of the DEBUG connector. This may be driven by UART1,
depending upon the setting of JP2 (DBGU_PE on the schematic, DEBUG_DIS
on the board):
---- ------------------------ -------------
J1 SCHEMATIC SAMA5D2
PIN NAME(s) PIO FUNCTION
---- ------------------------ -------------
2 DBGU_TXD DBGU_UTXD1_PD3 PD3 UTXD1
3 DBGU_RXD DBGU_URXD1_PD2 PD2 URXD1
---- ------------------------ -------------
Standard UART on Arduino connector (J21) is FLEXCOM4.
Terminology: FLEXCOM is the same as USART in previous SAMA5D versions.
---- ------- -------------
J21 BOARD SAMA5D2
PIN NAME PIO FUNCTION
---- ------- -------------
7 F4_TXD PD12 FLEXCOM4
8 F4_RXD PD13 FLEXCOM4
---- ------- -------------
Other USARTs are available on J22:
---- ------- -------------
J22 BOARD SAMA5D2
PIN NAME PIO FUNCTION
---- ------- -------------
3 F0_TXD PB28 FLEXCOM0
4 F0_RXD PB29 FLEXCOM0
5 F3_TXD PB23 FLEXCOM3
6 F3_RXD PB22 FLEXCOM3
---- ------- -------------
UARTs available of EXT1
---- ------- -------------
EXT1 BOARD SAMA5D2
PIN NAME PIO FUNCTION
---- ------- -------------
13 UART_RX PA23 FLEXCOM1
14 UART_TX PA24 FLEXCOM1
---- ------- ---- --------
UARTs available of EXT2
---- ------- -------------
EXT2 BOARD SAMA5D2
PIN NAME PIO FUNCTION
---- ------- -------------
13 UART_RX PB29 FLEXCOM0
14 UART_TX PB28 FLEXCOM0
---- ------- ---- --------
By default, the standard UART on Arduino connector (J21, FLEXCOM4) is
enabled in all of these configurations unless otherwise noted.
REVISIT: UART1 on the DBGU connect might be a better choice for the
default serial console
SAMA5D2-XULT 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_CORTEXA5=y
CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory
CONFIG_ARCH_CHIP="sama5"
CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
chip:
CONFIG_ARCH_CHIP_SAMA5=y
CONFIG_ARCH_CHIP_ATSAMA5D27=y
CONFIG_ARCH_BOARD - Identifies the boards/ subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD="sama5d2-xult" (for the SAMA5D2-XULT development board)
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_SAMA5D2_XULT=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=0x0002000 (128Kb)
CONFIG_RAM_START - The physical start address of installed DRAM
CONFIG_RAM_START=0x20000000
CONFIG_RAM_VSTART - The virtual start address of installed DRAM
CONFIG_RAM_VSTART=0x20000000
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.
Individual subsystems can be enabled:
REVISIT: Unverified, cloned text from the SAMA5D4-EK README.txt
CONFIG_SAMA5_DBGU - Debug Unit
CONFIG_SAMA5_PIT - Periodic Interval Timer
CONFIG_SAMA5_WDT - Watchdog timer
CONFIG_SAMA5_HSMC - Multi-bit ECC
CONFIG_SAMA5_SMD - SMD Soft Modem
CONFIG_SAMA5_FLEXCOM0 - Flexcom 0
CONFIG_SAMA5_FLEXCOM1 - Flexcom 0
CONFIG_SAMA5_FLEXCOM2 - Flexcom 0
CONFIG_SAMA5_FLEXCOM3 - Flexcom 0
CONFIG_SAMA5_FLEXCOM4 - Flexcom 0
CONFIG_SAMA5_UART0 - UART 0
CONFIG_SAMA5_UART1 - UART 1
CONFIG_SAMA5_UART2 - UART 2
CONFIG_SAMA5_UART3 - UART 3
CONFIG_SAMA5_UART4 - UART 4
CONFIG_SAMA5_TWI0 - Two-Wire Interface 0
CONFIG_SAMA5_TWI1 - Two-Wire Interface 1
CONFIG_SAMA5_SDMMC0 - SD MMC card interface 0
CONFIG_SAMA5_SDMMC1 - SD MMC card interface 1
CONFIG_SAMA5_SPI0 - Serial Peripheral Interface 0
CONFIG_SAMA5_SPI1 - Serial Peripheral Interface 1
CONFIG_SAMA5_TC0 - Timer Counter 0 (ch. 0, 1, 2)
CONFIG_SAMA5_TC1 - Timer Counter 1 (ch. 3, 4, 5)
CONFIG_SAMA5_PWM - Pulse Width Modulation Controller
CONFIG_SAMA5_ADC - Touch Screen ADC Controller
CONFIG_SAMA5_XDMAC0 - XDMA Controller 0
CONFIG_SAMA5_XDMAC1 - XDMA Controller 1
CONFIG_SAMA5_UHPHS - USB Host High Speed
CONFIG_SAMA5_UDPHS - USB Device High Speed
CONFIG_SAMA5_EMAC0 - Ethernet MAC 0 (GMAC0)
CONFIG_SAMA5_EMAC1 - Ethernet MAC 1 (GMAC1)
CONFIG_SAMA5_LCDC - LCD Controller
CONFIG_SAMA5_ISI - Image Sensor Interface
CONFIG_SAMA5_SSC0 - Synchronous Serial Controller 0
CONFIG_SAMA5_SSC1 - Synchronous Serial Controller 1
CONFIG_SAMA5_SHA - Secure Hash Algorithm
CONFIG_SAMA5_AES - Advanced Encryption Standard
CONFIG_SAMA5_TDES - Triple Data Encryption Standard
CONFIG_SAMA5_TRNG - True Random Number Generator
CONFIG_SAMA5_ARM - Performance Monitor Unit
CONFIG_SAMA5_FUSE - Fuse Controller
CONFIG_SAMA5_MPDDRC - MPDDR controller
Some subsystems can be configured to operate in different ways. The drivers
need to know how to configure the subsystem.
CONFIG_SAMA5_PIOA_IRQ - Support PIOA interrupts
CONFIG_SAMA5_PIOB_IRQ - Support PIOB interrupts
CONFIG_SAMA5_PIOC_IRQ - Support PIOD interrupts
CONFIG_SAMA5_PIOD_IRQ - Support PIOD interrupts
CONFIG_USART0_SERIALDRIVER - Flexcom0 is configured as a UART
CONFIG_USART1_SERIALDRIVER - Flexcom1 is configured as a UART
CONFIG_USART2_SERIALDRIVER - Flexcom2 is configured as a UART
CONFIG_USART3_SERIALDRIVER - Flexcom3 is configured as a UART
CONFIG_USART4_SERIALDRIVER - Flexcom4 is configured as a UART
AT91SAMA5 specific device driver settings
CONFIG_SAMA5_DBGU_SERIAL_CONSOLE - selects the DBGU
for the console and ttyDBGU
CONFIG_SAMA5_DBGU_RXBUFSIZE - Characters are buffered as received.
This specific the size of the receive buffer
CONFIG_SAMA5_DBGU_TXBUFSIZE - Characters are buffered before
being sent. This specific the size of the transmit buffer
CONFIG_SAMA5_DBGU_BAUD - The configure BAUD of the DBGU.
CONFIG_SAMA5_DBGU_PARITY - 0=no parity, 1=odd parity, 2=even parity
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 DBGU).
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_PARITY - 0=no parity, 1=odd parity, 2=even parity
CONFIG_U[S]ARTn_2STOP - Two stop bits
AT91SAMA5 USB Host Configuration
Pre-requisites
CONFIG_USBDEV - Enable USB device support
CONFIG_USBHOST - Enable USB host support
CONFIG_SAMA5_UHPHS - Needed
CONFIG_SAMA5_OHCI - Enable the STM32 USB OTG FS block
CONFIG_SCHED_WORKQUEUE - Worker thread support is required
Options:
CONFIG_SAMA5_OHCI_NEDS
Number of endpoint descriptors
CONFIG_SAMA5_OHCI_NTDS
Number of transfer descriptors
CONFIG_SAMA5_OHCI_TDBUFFERS
Number of transfer descriptor buffers
CONFIG_SAMA5_OHCI_TDBUFSIZE
Size of one transfer descriptor buffer
CONFIG_USBHOST_INT_DISABLE
Disable interrupt endpoint support
CONFIG_USBHOST_ISOC_DISABLE
Disable isochronous endpoint support
CONFIG_USBHOST_BULK_DISABLE
Disable bulk endpoint support
config SAMA5_OHCI_REGDEBUG
Configurations
==============
Information Common to All Configurations
----------------------------------------
Each SAMA5D2-XULT configuration is maintained in a sub-directory and
can be selected as follow:
tools/configure.sh sama5d2-xult:<subdir>
Before building, make sure the PATH environment variable includes 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
see additional README.txt files in the NuttX tools repository.
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. Unless stated otherwise, all configurations generate console
output on the DBGU (J23).
3. All of these configurations use the Code Sourcery for Windows 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_WINDOWS=y : Microsoft Windows
CONFIG_WINDOWS_CYGWIN=y : Using Cygwin or other POSIX environment
System Type -> Toolchain:
CONFIG_ARMV7A_TOOLCHAIN_GNU_EABI=y : GNU EABI toolchain
4. The SAMA5Dx is running at 528MHz by default in these configurations.
Board Selection -> CPU Frequency
CONFIG_SAMA5D2XULT_528MHZ=y : Enable 528MHz operation
CONFIG_BOARD_LOOPSPERMSEC=65775 : Calibrated on SAMA5D3-Xplained at
: 528MHz running from SDRAM
Configuration Sub-directories
-----------------------------
Summary: Some of the descriptions below are long and wordy. Here is the
concise summary of the available SAMA5D2-XULT configurations:
nsh: This is a basic NuttShell (NSH) configuration.
There may be issues with some of these configurations. See the details
for status of individual configurations.
Now for the gory details:
netnsh:
This is a network enabled configuration based on the NuttShell (NSH).
The CDC-ECM driver is enabled, so you can plug a USB cable into the
USB-Micro port (USB-A) and the board will appear as an CDC-ECM
ethernet adapter.
nsh:
This configuration directory provide the NuttShell (NSH). This is a
very simple NSH configuration upon which you can build further
functionality.
NOTES:
1. This configuration uses the UART1 (PD2 and PD3) for the serial
console. USART1 is available at the "DBGU" RS-232 connector (J24).
This is easily changed by reconfiguring to (1) enable a different
serial peripheral, and (2) selecting that serial peripheral as the
console device.
2. By default, this configuration is set up to build on Windows
under either a Cygwin or MSYS environment using a recent, Windows-
native, generic ARM EABI GCC toolchain (such as the ARM supported
toolchain). Both the build environment and the toolchain
selection can easily be changed by reconfiguring:
CONFIG_HOST_WINDOWS=y : Windows operating system
CONFIG_WINDOWS_CYGWIN=y : POSIX environment under windows
CONFIG_ARMV7A_TOOLCHAIN_EABIW=y : Generic GCC EABI toolchain for Windows
If you are running on Linux, make *certain* that you have
CONFIG_HOST_LINUX=y *before* the first make or you will create a
corrupt configuration that may not be easy to recover from. See
the warning in the section "Information Common to All Configurations"
for further information.
4. This configuration supports logging of debug output to a circular
buffer in RAM. This feature is discussed fully in this Wiki page:
https://cwiki.apache.org/confluence/display/NUTTX/SYSLOG . Relevant
configuration settings are summarized below:
File System:
Device Drivers:
CONFIG_RAMLOG=y : Enable the RAM-based logging feature.
CONFIG_RAMLOG_SYSLOG=y : This enables the RAM-based logger as the
system logger.
CONFIG_RAMLOG_NONBLOCKING=y : Needs to be non-blocking for dmesg
CONFIG_RAMLOG_BUFSIZE=16384 : Buffer size is 16KiB
NOTE: This RAMLOG feature is really only of value if debug output
is enabled. But, by default, no debug output is disabled in this
configuration. Therefore, there is no logic that will add anything
to the RAM buffer. This feature is configured and in place only
to support any future debugging needs that you may have.
If you don't plan on using the debug features, then by all means
disable this feature and save 16KiB of RAM!
NOTE: There is an issue with capturing data in the RAMLOG: If
the system crashes, all of the crash dump information will into
the RAMLOG and you will be unable to access it! You can tell that
the system has crashed because (a) it will be unresponsive and (b)
the RED LED will be blinking at about 2Hz.
That is another good reason to disable the RAMLOG!
5. This configuration executes out of SDRAM flash and is loaded into
SDRAM from NAND, Serial DataFlash, SD card or from a TFTPC sever via
U-Boot, BareBox, or the DRAMBOOT configuration described above. Data
also is positioned in SDRAM.
The load address is different for the DRAMBOOT program and the Linux
bootloaders. This can easily be reconfigured, however:
CONFIG_SAMA5D2XULT_DRAM_BOOT=y
See the section above entitled "Creating and Using DRAMBOOT" above
for more information. Here is a summary of the steps that I used
to boot the NSH configuration:
a. Create the DRAMBOOT program as described above. It should be
configured with CONFIG_SAMA5D2XULT_DRAM_START=y so that DRAMBOOT
will immediately start the program. You may not want to do
this is your prefer to break in with GDB.
b. Write the DRAMBOOT program binary (nuttx.bin) to a microSD
card as "boot.bin". Insert the microSD card into the boar;
The ROM Booloader should now boot DRAMBOOT on reset and you
should see this message:
Send Intel HEX file now
c. Build the NSH version of NuttX. Send the Intel HEX of NSH
at the prompt. After the file is received, NSH should start
automatically.
At times the past, have have tested with nuttx.bin on an SD card and
booting with U-Boot. These are the commands that I used to boot NuttX
from the SD card:
U-Boot> fatload mmc 0 0x20008000 nuttx.bin
U-Boot> go 0x20008040
6. Board LEDs and buttons are supported as described under "Buttons and
LEDs". The interrupt button test is also enabled as an NSH built-in
commands. To run this test, you simply inter the command:
nsh>buttons [npresses]
The interrupt button test will log button press information to the
syslog. Since the RAMLOG is enabled, the SYSLOG output will be
captured to a circular buffer in ram and may be examined using the
NSH dmesg command:
nsh> buttons 2
nsh> dmesg
maxbuttons: 2
Attached handler at 200106f0 to button 0 [PB_USER], oldhandler:0
IRQ:81 Button 0:PB_USER SET:01:
PB_USER depressed
IRQ:81 Button 0:PB_USER SET:00:
PB_USER released
IRQ:81 Button 0:PB_USER SET:01:
PB_USER depressed
IRQ:81 Button 0:PB_USER SET:00:
PB_USER released
7. This configuration supports /dev/null, /dev/zero, and /dev/random.
CONFIG_DEV_NULL=y : Enables /dev/null
CONFIG_DEV_ZERO=y : Enabled /dev/zero
Support for /dev/random is implemented using the SAMA5D2's True
Random Number Generator (TRNG). See the section above entitled
"TRNG and /dev/random" for information about configuring /dev/random.
CONFIG_SAMA5_TRNG=y : Enables the TRNG peripheral
CONFIG_DEV_RANDOM=y : Enables /dev/random
8. This configuration has support for NSH built-in applications enabled.
No built-in applications are enabled, however.
9. This configuration has support for the FAT and PROCFS file
systems built in.
The FAT file system includes long file name support. Please be aware
that Microsoft claims patents against the long file name support (see
more discussion in the top-level NOTICE file).
CONFIG_FS_FAT=y : Enables the FAT file system
CONFIG_FAT_LCNAMES=y : Enable lower case 8.3 file names
CONFIG_FAT_LFN=y : Enables long file name support
CONFIG_FAT_MAXFNAME=32 : Arbitrarily limits the size of a path
segment name to 32 bytes
The PROCFS file system is enabled simply with:
CONFIG_FS_PROCFS=y : Enable PROCFS file system
10. The Real Time Clock/Calendar (RTC) is enabled in this configuration.
See the section entitled "RTC" above for detailed configuration
settings.
The RTC alarm is not enabled by default since there is nothing in
this configuration that uses it. The alarm can easily be enabled,
however, as described in the "RTC" section.
The time value from the RTC will be used as the NuttX system time
in all timestamp operations. You may use the NSH 'date' command
to set or view the RTC as described above in the "RTC" section.
NOTE: If you want the RTC to preserve time over power cycles, you
will need to install a battery in the battery holder (J12) and close
the jumper, JP13.
sdmmcnsh:
This is a configuration based on the NuttShell (NSH). The SDMMC
peripheral is enabled, and can read and write to a VFAT filesystem
on the SD Card.
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