mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-22 19:23:07 +00:00
3f6b4ea225
Back in the day on early board samples built-in Digilent JTAG probe was not functional so we used externally attached Ashling Opella-XD probe. But now with production units everything works as expected and so we anybody may enjoy readily avaialble built-in JTAG probe so we specify Digilent oprion on MDB's command line example. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
83 lines
3.6 KiB
Text
83 lines
3.6 KiB
Text
================================================================================
|
|
Useful notes on bulding and using of U-Boot on
|
|
ARC EM Software Development Platform (AKA EMSDP)
|
|
================================================================================
|
|
|
|
BOARD OVERVIEW
|
|
|
|
The DesignWare ARC EM Software Development Platform is FPGA-bases platform
|
|
for rapid software development on the ARC EM family of processors.
|
|
|
|
Since this board is based on FPGA it's possible to load and use different
|
|
versions of ARC EM CPUs. U-Boot is built to be run on the simplest
|
|
possible configuration which means the same one binary will work on more
|
|
advanced configurations as well.
|
|
|
|
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.
|
|
|
|
* 256 KiB of "ROM"
|
|
- This so-called "ROM" is a part of FPGA image and even though it
|
|
might be unlocked for writes its initial content will be restored
|
|
on the next power-on.
|
|
|
|
|
|
BUILDING U-BOOT
|
|
|
|
1. Configure U-Boot:
|
|
------------------------->8----------------------
|
|
make emsdp_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 EMSDP board is supposed to auto-start U-Boot image stored in ROM on
|
|
power-on. For that make sure VCCIO DIP-switches are all in "off" state.
|
|
|
|
2. Though it is possible to load U-Boot as a simple Elf file via JTAG right
|
|
in "ROM" and start it from the debugger. One important note here we first
|
|
need to enable writes into "ROM" by writing 1 to 0xf0001000.
|
|
|
|
2.1. In case of proprietary MetaWare debugger run:
|
|
------------------------->8----------------------
|
|
mdb -digilent -OK -preloadexec="eval *(int*)0xf0001000=0" u-boot
|
|
------------------------->8----------------------
|