[U-Boot] [PATCH] iot_dk: Add README
Alexey Brodkin
alexey.brodkin at synopsys.com
Wed Oct 31 15:44:05 UTC 2018
Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
---
board/synopsys/iot_devkit/README | 145 +++++++++++++++++++++++++++++++
1 file changed, 145 insertions(+)
create mode 100644 board/synopsys/iot_devkit/README
diff --git a/board/synopsys/iot_devkit/README b/board/synopsys/iot_devkit/README
new file mode 100644
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--- /dev/null
+++ b/board/synopsys/iot_devkit/README
@@ -0,0 +1,145 @@
+================================================================================
+Useful notes on bulding and using of U-Boot on
+ARC IoT Development Kit (AKA IoTDK)
+================================================================================
+
+ BOARD OVERVIEW
+
+ The DesignWare ARC IoT Development Kit is a versatile platform that includes
+ the necessary hardware and software to accelerate software development and
+ debugging of sensor fusion, voice recognition and face detection designs.
+
+ The ARC IoT Development Kit includes a silicon implementation of the
+ ARC Data Fusion IP Subsystem running at 144 MHz on SMIC's
+ 55-nm ultra-low power process, and a rich set of peripherals commonly used
+ in IoT designs such as USB, UART, SPI, I2C, PWM, SDIO and ADCs.
+
+ The board is shipped with pre-installed U-Boot in non-volatile memory
+ (eFlash) so on power-on user sees U-Boot start header and command line
+ prompt which might be used for U-Boot environment fine-tuning, manual
+ loading and execution of user application binaries etc.
+
+ The board has the following features useful for U-Boot:
+ * On-board 2-channel FTDI TTL-to-USB converter
+ - The first channel is used for serial debug port (which makes it possible
+ to use a serial connection on pretty much any host machine be it
+ Windows, Linux or Mac).
+ On Linux machine typucally FTDI serial port would be /dev/ttyUSB0.
+ There's no HW flow-control and baud-rate is 115200.
+
+ - The second channel is used for built-in Digilent USB JTAG probe.
+ That means no extra hardware is required to access ARC core from a
+ debugger on development host. Both proprietary MetaWare debugger and
+ open source OpenOCD + GDB client are supported.
+
+ - Also with help of this FTDI chip it is possible to reset entire
+ board with help of a special `rff-ftdi-reset` utility, see:
+ https://github.com/foss-for-synopsys-dwc-arc-processors/rff-ftdi-reset
+
+ * Micro SD-card slot
+ - U-Boot expects to see the very first partition on the card formatted as
+ FAT file-system and uses it for keeping its environment in `uboot.env`
+ file. Note uboot.env is not just a text file but it is auto-generated
+ file created by U-Boot on invocation of `saveenv` command.
+ It contains a checksum which makes this saved environment invalid in
+ case of maual modification.
+
+ - There might be more useful files on that first FAT partition like
+ user applications, data files etc.
+
+ * USB OTG connector
+ - U-Boot may access USB mass-storage devices attached to this connector.
+ Note only FAT file-system is supported. It might be used for storing
+ user application binaries as well as micro SD-card mentioned above.
+
+ * The following memories are avaialble on the board:
+ - eFlash: 256 KiB @ 0x0000_0000
+ A non-volatile memory from which ARC core may execute code directly.
+ Still is is not direcly writable, thus this is not an ordinary RAM.
+
+ - ICCM: 256 KiB @ 0x2000_0000
+ Instruction Closely Coupled Memory - fast on-chip memory primary used
+ for code being executed, still data could be placed in this memory too.
+ In that sense it's just a general purpose RAM.
+
+ - SRAM: 128 KiB @ 0x3000_0000
+ On-chip SRAM. From user perspective is the same as ICCM above.
+
+ - DCCM: 128 KiB @ 0x8000_0000
+ Data Closely Coupled Memory is similar to ICCM with a major difference -
+ ARC core cannot execute code from DCCM. So this is very special RAM
+ only suitable for data.
+
+ BUILDING U-BOOT
+
+ 1. Configure U-Boot:
+ ------------------------->8----------------------
+ make iot_devkit_defconfig
+ ------------------------->8----------------------
+
+ 2. To build Elf file (for example to be used with host debugger via JTAG
+ connection to the target board):
+ ------------------------->8----------------------
+ make mdbtrick
+ ------------------------->8----------------------
+
+ This will produce `u-boot` Elf file.
+
+ 3. To build binary image to be put in "ROM":
+ ------------------------->8----------------------
+ make u-boot.bin
+ ------------------------->8----------------------
+
+
+ EXECUTING U-BOOT
+
+ 1. The IoTDK board is supposed to auto-start U-Boot image stored in eFlash on
+ power-on. Note it's possible to update that image - follow instructions in
+ user's manual.
+
+ 2. Though it is possible to load and start U-Boot as a simple Elf file
+ via JTAG right in ICCM. For that it's required to re-configure U-Boot
+ so it gets linked to ICCM address 0x2000_0000 (remember eFlash is not
+ direcly writable).
+ Run U-Boot's configuration utility with "make menuconfig", go to
+ "Boot images" and change "Text Base" from default 0x00000000 to
+ 0x20000000. Exit & save new configuration. Now run "make mdbtrick" to
+ build new Elf.
+
+ 2.1. In case of proprietary MetaWare debugger run:
+ ------------------------->8----------------------
+ mdb -digilent u-boot
+ ------------------------->8----------------------
+
+ USING U-BOOT
+
+ Note due to limited memory size it's supposed that user will run binary
+ images of their applications instead of loading Elf files.
+
+ 1. To load and start application binary from micro SD-card execute
+ the following commands in U-Boot's shell:
+ ------------------------->8----------------------
+ fatload mmc 0 0x20000000 yourapp.bin
+ go 0x20000000
+ ------------------------->8----------------------
+
+ 2. To load and start application binary from USB mass-storage device execute
+ the following commands in U-Boot's shell:
+ ------------------------->8----------------------
+ usb start
+ fatload usb 0x20000000 yourapp.bin
+ go 0x20000000
+ ------------------------->8----------------------
+
+ 3. To have a sequence of commands executed on U-Boot start put those
+ commands in "bootcmd" with semicolon between them.
+ For example to get (1) done automatically:
+ ------------------------->8----------------------
+ setenv bootcmd fatload mmc 0 0x20000000 yourapp.bin\; go 0x20000000
+ saveenv
+ ------------------------->8----------------------
+
+ 4. To reboot the board just run:
+ ------------------------->8----------------------
+ reset
+ ------------------------->8----------------------
--
2.17.2
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