From 0921f9294bd10b6639c24623bed6d9ddfa24404f Mon Sep 17 00:00:00 2001 From: Alexey Brodkin Date: Fri, 15 Jun 2018 18:20:59 +0300 Subject: [PATCH] ARC: EMDK: Add readme Signed-off-by: Alexey Brodkin --- board/synopsys/emdk/README | 82 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 board/synopsys/emdk/README diff --git a/board/synopsys/emdk/README b/board/synopsys/emdk/README new file mode 100644 index 0000000000..706b547a9e --- /dev/null +++ b/board/synopsys/emdk/README @@ -0,0 +1,82 @@ +================================================================================ +Useful notes on bulding and using of U-Boot on ARC EM Development Kit (AKA EMDK) +================================================================================ + + BOARD OVERVIEW + + The DesignWare ARC EM Development Kit 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 emdk_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 EMDK 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 -dll=opxdarc.so -OK -preloadexec="eval *(int*)0xf0001000=0" u-boot + ------------------------->8----------------------