update readme

README.md

@@ -8,7 +8,34 @@ An OMF linker for Merlin 8/16+ REL files.  Why?  ummm....
 * `-X`: inhibit expressload segment
 * `-C`: inhibit super relocation records
 * `-D`: define an absolute label.  value can use `$`, `0x`, or `%` prefix.
-* `-o`: specify output file. default is `gs.out`
+* `-S`: treat input file as a linker command file
+* `-o`: specify output file. default is `omf.out`
+* `-v`: be verbose
+
+If there is one input file and it ends with `.S` (case insensitive), it is treated as a linker command file.
+
+### Linker Command File
+
+The following opcodes are supported:
+
+`END`,`DAT`, `PFX`, `TYP`, `ADR`, `ORG`, `KND`, `ALI`, `DS`, `LKV`, `VER`, `LNK`, `IMP`, `SAV`, `KBD`,
+`POS`, `LEN`, `EQ`, `EQU`, `=`, `GEQ`, `EXT`, `DO`, `ELS`, `FIN`
+
+* `VER`: only allows OMF version 2.
+* `LKV`: 0 (binary), 1 (single segment OMF), 2 (multi segment OMF)
+* `IMP`: (qasm) - import a binary file. Entry name is the file name with non alphanumerics converted to `_`
+* `KBD`: won't prompt if label was previously defined (via `-D` for example)
+
+
+No operand math is allowed at this time.
+
+
+
+
+### Current Status
+
+Usable, if you can find a use for it.  Linking Marinetti (after assembling with Merlin 16+) generates an equivalent
+OMF file.  The file is not identical due to differences in relocation records but OMF Analyzer COMPARE considers them identical.
 
 ### Building
 
@@ -19,4 +46,3 @@ make
 ```
 
 Requires a c++17 compiler. (ie, ubuntu bionic or OS X 10.13).  Also assumes a little-endian environment :/
-