From ae8dbd0b5e77ca25476ff371ffce4c127453a95d Mon Sep 17 00:00:00 2001
From: Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>
Date: Thu, 4 Feb 2021 07:29:57 +0100
Subject: [PATCH] README: update xilinx section

---
 README.md | 34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index 1fb5f6d..9ef8b70 100644
--- a/README.md
+++ b/README.md
@@ -264,29 +264,45 @@ configured in SPI mode and sfl primitive used to access EPCQ SPI flash.**
 This interface is used for SPI communication only when the dedicated svf is
 loaded in RAM, rest of the time, user is free to use for what he want.**
 
-### ARTY and Spartan Edge Accelerator Board
+### <span style="text-decoration:underline">Xilinx based boards</span>
 
 To simplify further explanations, we consider the project is generated in the
 current directory.
 
-**Note: Spartan Edge Accelerator Board has only pinheader, so the cable must be
-provided**
+**Note:**
+1. Spartan Edge Accelerator Board has only pinheader, so the cable must be provided
+2. a *JTAG* <-> *SPI* bridge (used to write bitstream in FLASH) is available for some device, see
+[spiOverJtag](https://github.com/trabucayre/openFPGALoader/tree/master/spiOverJtag) to check if your model is supported
 
-#### loading in memory:
+<span style="color:red">**Warning** *.bin* may be loaded in memory or in flash, but this extension is a classic extension
+for CPU firmware and, by default, *openFPGALoader* load file in memory, double check
+*-m* / *-f* when you want to use a firmware for a softcore
+(or anything, other than a bitstream) to write somewhere in the FLASH device).</span>
 
 *.bit* file is the default format generated by *vivado*, so nothing special
 task must be done to generates this bitstream.
 
+*.bin* is not, by default, produces. To have access to this file you need to configure the tool:
+- **GUI**: *Tools* -> *Settings* -> *Bitstreams* -> check *-bin_file*
+- **TCL**: append your *TCL* file with `set_property STEPS.WRITE_BITSTREAM.ARGS.BIN_FILE true [get_runs impl_1]`
+
+#### loading in memory:
+
+<span style="text-decoration:underline">*.bit* and *.bin* are allowed to be loaded in memory.</span>
+
 __file load:__
 ```bash
-openFPGALoader -b arty *.runs/impl_1/*.bit
+openFPGALoader [-m] -b arty *.runs/impl_1/*.bit (or *.bin)
 ```
 or
 ```bash
-openFPGALoader -b spartanEdgeAccelBoard -c digilent_hs2 *.runs/impl_1/*.bit
+openFPGALoader [-m] -b spartanEdgeAccelBoard -c digilent_hs2 *.runs/impl_1/*.bit (or *.bin)
 ```
 
-#### SPI flash (only for ARTY):
+#### SPI flash:
+
+<span style="text-decoration:underline">*.bit*, *.bin*, and *.mcs* are supported for FLASH.</span>
+
 .mcs must be generates through vivado with a tcl script like
 ```tcl
 set project [lindex $argv 0]
@@ -309,8 +325,10 @@ vivado -nolog -nojournal -mode batch -source script.tcl -tclargs myproject
 
 __file load:__
 ```bash
-openFPGALoader -b arty *.runs/impl_1/*.mcs
+openFPGALoader -f -b arty *.runs/impl_1/*.mcs (or .bit / .bin)
 ```
+**Note: *-f* is required to write bitstream (without them *.bit* and *.bin* are loaded in memory)**
+
 ### MachXO2/MachXO3 Starter Kit
 
 #### Flash memory: