I received an i.MX7D SABRE-SD last week. All relevant documents, code, etc. was downloaded. One thing I noted is pretty much all documents are packaged for i.MX6SoloX. Likely not a big deal but even the FreeRTOS source references i.MX6SX not i.MX7.
First I simply powered up with the provided uSD. Get the openEmbedded GUI and all. Looks good.
Unarchived the rel_imx_4.1.15_1.1.0_ga.tar.bz2 image, installed latest cross compilers on my Linux workstation, built the image, loaded and ran. Good. Did more work on the kernel - tracked down relevant 4.1.15 RT patch set, applied, fought the gpu-viv code for a while (until I realized it isn't needed for i.MX7 build), updated imx-sdma.c as documented in meta-fsl-arm rt. Replaced rootfs with minimal Debian. Fired everything up and it runs.
Today back to original rel_imx_4.1.15_1.1.0_ga image and working to light up the M4. Pulled the necessary compilers from launchpad.net, set up the ARMGCC_DIR environmental variable and built rpmsg pingpong demo. Everything looks good so far. Copy the .bin onto the FAT section of uSD. Open terminals to ttyUSB0 & ttyUSB1. Plug uSD (in carrier) into the i.MX7D SABRE-SD and powered on. Interrupted uboot during boot and copied bin image into memory using the instructions here, i.MX 7Dual SABRE Board|NXP No joy. Nothing in M4 console terminal.
Ok, backed away from rpmsg, let's just do "hello_world" to verify things. Same behavior. It seems there are at least three points of possible failure - bad build, bad ttyUSB1 circuitry, bad silicon.
There are no errors on the build. Output of CMakeOutput.log
The target system is: Generic - - arm
The host system is: Linux - 3.19.0-61-generic - x86_64
Checking whether the ASM compiler is GNU using "--version" matched "(GNU assembler)|(GCC)|(Free Software Foundation)":
arm-none-eabi-gcc (GNU Tools for ARM Embedded Processors) 5.3.1 20160307 (release) [ARM/embedded-5-branch revision 234589]
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Where can I find a known good binary to eliminate the build image? Are there other techniques to determine whether the M4 is running but silent (possibly indicating a tty issue)? Looking for some ideas and/or guidance.
Thank you in advance, Joe