DSP Quick start - with Linux OS

Added by Paul Strutt about 3 years ago

We currently have a development on an OMAPL138 device that launches an FPGA and DSP image from the Linux OS. We are using the Arm (Linux) to run certain tasks (mainly communications) while using the DSP and FPGA to do most of the front end I/O handling.

The system works well except that there is a long delay between power up and the FPGA and DSP being started, and this can cause some issues with the hardware. One option we would like to explore is to load (a possibly cut-down) DSP image and FPGA image from U-Boot, and then load the Linux kernel in parallel. When Linux is up and running it will then either start talking to the DSP image that is already running or load a new DSP image to take over the hardware control and allow communication to the Linux OS.

The following wiki page documents how to start a DSP image from u-boot

Our current boot command loads the Linux kernel using the bootm command

sf probe 0;sf read 0xc0700000 0x100000 0x300000;bootm 0xC0700000

The Wiki above suggests it should be possible to load the dsp using a suitable read command and then calling bootdsp instead of bootm e.g.

sf probe 0; sf read 0xc0700000 0x400000 0x300000;bootdsp 0xc0700000

Is it possible to do both and are there any pitfalls to be aware of? e.g.

sf probe 0;sf read 0xc0700000 0x400000 0x300000;bootdsp 0xc0700000;sf read 0xc0700000 0x100000 0x300000;bootm 0xC0700000

Replies (1)

RE: DSP Quick start - with Linux OS - Added by Jonathan Cormier about 3 years ago

What immediately comes to my mind, is the concern that linux during boot touches a lot of registers, setting pinmuxes, configuring clocks, etc. You may run into a situation where the DSP tries to access a resource as the kernel is reconfiguring it and cause the DSP or kernel to crash. So you'd have to be careful with what peripherals you use and might need to modify certain drivers in the kernel so they don't reconfigure the particular interface if the DSP uses it.

I'm not sure if we've tried launching both at the same time. Perhaps someone else can add to this.

Loading the fpga from u-boot should be no problem, we do this all the time.

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