PRU-framework

PRUSS support for newer kernels (3.14 and above). A complete communication framework between ARM and PRUSS.

##How to build.

###Kernel Module.

1. Install the correct kernel headers.

   sudo apt-get install linux-headers-uname -r

2. Make backup of existing pruss_remoteproc driver (if any)

   sudo cp /lib/modules/$(uname -r)/kernel/drivers/remoteproc/pruss_remoteproc.ko /lib/modules/$(uname -r)/kernel/drivers/remoteproc/pruss_remoteproc.ko.back

3. cd to /drivers/remoteproc in cloned repo and run 'make' command

   make

4. Install the compiled module

   make install

###PRU firmware

1. Install TI-PRU Code generation tool from this link

2. Clone TI's PRU software package library from this link to any suitable directory

   Example:

   cd /usr/share

   git clone git://git.ti.com/pru-software-support-package/pru-software-support-package.git

3. Edit /firmware/Makefile variable SWDIR to the directory in which you cloned repo in Step 2 (skip this step if you cloned in /usr/share)

4. cd to /firmware

   make

5. Install firmware

   if above steps are performed on host PC make install-tobb

   if above steps are perfomed on BBB make install-frombb

###User Library and Examples.

1. cd to /userspace and run 'make' command. This will compile the library and examples

   make

###How to use library.

(Assumes you have followed previous steps correctly)

1. Copy pru firmware to /lib/firmware. Firmware name for pru0 must be 'rproc-pru0-fw' and for pru1 it must be 'rproc-pru1-fw'. (without ' ')

2. Load driver by using modprobe pruss_remoteproc.

3. This will load the pru firmwares and boot the remote processors.

4. cd to /userspace/examples

5. Execute ./poll ( program waits for interrupt from PRU )

6. In another terminal execute ./write

###Library functions

int pruss_write(unsigned const int mem_name, int wordoffset, int *data, size_t bytelength)

Writes buffer pointed at by 'data' pointer to PRU memory.
@mem_name : can take PRU_DRAM0 / PRU_DRAM1 / PRU_SHRAM as values
@wordoffset : offset within specified memory type.
@bytelength : length of data to be copied (in bytes).

Returns 0 on success.

---

int pruss_read(unsigned const int mem_name, int wordoffset, int *data, size_t bytelength)

Reads into 'data' pointer from PRU memory.
@mem_name : can take PRU_DRAM0 / PRU_DRAM1 / PRU_SHRAM as values
@wordoffset : offset within specified memory type.
@bytelength : length of data to be copied (in bytes).

Returns 0 on success.

---

int pruss_interrupt(int sysevent)

Send user provided sysevent to PRU INTC.

@sysevent : Sysevent number ( 0 – 63 )

Returns 0 on success.

---

bool check_device_status(int pru_num)

@pru_num : PRU core id ( 0 or 1 )

Returns true if specified core is powered up. Otherwise false.

---

int hostevt_poll( int hostevt, void (*callback)(int) )

This function can either be blocking or non-blocking depending on timeout provided by user ( in libpru.h )

@hostevt : EVTOUT0 – EVTOUT7
@callback : user provided callback function. Host event int is argument. No return.
@TIMEOUT (in libpru.h): -1 for indefinite block
>0 wait time before releasing poll

---

int pruss_boot(char *fwname,int pru_num)

Boots the PRU core.

@fwname : path to PRU firmware
@pru_num: PRU0 / PRU1

Returns 0 on success

---

int pruss_shutdown(int pru_num)

Shutdown PRU core.

@pru_num: PRU0 / PRU1

Returns 0 on success