On Mon, 23 Aug 2021 at 18:49, Tong Ho <tong...@xilinx.com> wrote: > > Add BBRAM and eFUSE usage to the Xilinx Versal Virt board > document. > > Signed-off-by: Tong Ho <tong...@xilinx.com> > --- > docs/system/arm/xlnx-versal-virt.rst | 49 ++++++++++++++++++++++++++++ > 1 file changed, 49 insertions(+) > > diff --git a/docs/system/arm/xlnx-versal-virt.rst > b/docs/system/arm/xlnx-versal-virt.rst > index 27f73500d9..84afac3734 100644 > --- a/docs/system/arm/xlnx-versal-virt.rst > +++ b/docs/system/arm/xlnx-versal-virt.rst > @@ -32,6 +32,8 @@ Implemented devices: > - OCM (256KB of On Chip Memory) > - XRAM (4MB of on chip Accelerator RAM) > - DDR memory > +- BBRAM (36 bytes of Battery-backed RAM) > +- eFUSE (3072 bytes of one-time field-programmable bit array) > > QEMU does not yet model any other devices, including the PL and the AI > Engine. > > @@ -175,3 +177,50 @@ Run the following at the U-Boot prompt: > fdt set /chosen/dom0 reg <0x00000000 0x40000000 0x0 0x03100000> > booti 30000000 - 20000000 > > +BBRAM File Backend > +"""""""""""""""""" > +BBRAM can have an optional file backend, which must a seekable
"must be" > +binary file with a size of 36 bytes or larger. A file with all > +binary 0s is a 'blank'. > + > +To add a file-backend for the BBRAM: > + > +.. code-block:: bash > + > + -drive if=pflash,index=0,file=versal-bbram.bin,format=raw > + > +To use a different index value, N, from default of 0, add: > + > +.. code-block:: bash > + > + -global xlnx,bbram-ctrl.drive-index=N > + > +eFUSE File Backend > +"""""""""""""""""" > +eFUSE can have an optional file backend, which must a seekable "must be" > +binary file with a size of 3072 bytes or larger. A file with all > +binary 0s is a 'blank'. > + > +To add a file-backend for the eFUSE: > + > +.. code-block:: bash > + > + -drive if=pflash,index=1,file=versal-efuse.bin,format=raw > + > +To use a different index value, N, from default of 1, add: > + > +.. code-block:: bash > + > + -global xlnx,efuse.drive-index=N > + > +.. warning:: > + In actual physical Versal, BBRAM and eFUSE contain sensitive data. > + The QEMU device models do **not** encrypt nor obfuscate any data > + when holding them in models' memory or when writing them to their > + file backends. > + > + Thus, a file backend should be used with caution, and 'format=luks' > + is highly recommended (albeit with usage complexity). > + > + Better yet, do not use actual product data when running guest image > + on this Xilinx Versal Virt board. | Stray '|' at the end of the line. -- PMM
