add paragraph about firmware address

diff --git a/HDL_workflow/ls2.mdwn b/HDL_workflow/ls2.mdwn
index ec647175a0eb6c42dd41f627b3d38fe5f7634fc8..af04de74a27f3aadece22838508c4c5bf805340d 100644 (file)
--- a/HDL_workflow/ls2.mdwn
+++ b/HDL_workflow/ls2.mdwn
@@ -72,3 +72,21 @@ In fact any core can be used with ls, as long as it is compliant with
 the interfaces.  Both Wishbone Interfaces must be WB4 Pipeline
 compliant (proper stall handling) or the stall signal faked externally
 with a wrapper: `stall=stb&~ack`
+
+# Using ls2 with verilator
+
+first you need to build hello_world (or any other firmware) to start at 
+0xff000000. Then you can run build ls.v using that firmware:
+
+    python3 src/ls2.py sim /tmp/ff000000_hw.bin
+
+The output of that command is:
+
+    platform sim /tmp/ff000000_hw.bin None
+    fpga sim firmware /tmp/ff000000_hw.bin
+    ddr pins None
+    spiflash pins None
+    ethmac pins None
+    hyperram pins [<lambdasoc.periph.hyperram.HyperRAMPads object at 0x735e9940dd30>]
+    fw at address ff000000
+    SRAM 0x8000 at address 0x0
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