Revamped parameters a bit, added -b and -f to set BSS start and flags…

…, globally and per file. Added diagnostic cart support

readme.md

@@ -1,25 +1,42 @@
 USM
----
+===
 
 Small tool to ease the creation of Atari ST cart images.
 
 Usage
-=====
+-----
 
 From the command line:
 
-`usm [s] image_filename <list_of_programs_to_add>`
+`usm [-s] [-d] [-bX] [-fY] image_filename <list of programs to add with optional -b and -f>`
 
-where *s* is optional and allows creation of STEem Engine compatible carts, *image_filename* is the filename of the cart image and *list_of_programs_to_add* is a list of ST PRG programs to add to the image.
+where:
+
+- *-s* is optional and allows creation of STEem Engine compatible carts
+- *-d* enables creation of diagnostic cartridges (only one program allowed, which will relocate to $fa0004)
+- *-bX* allows setting the BSS address to an address other than the default ($20000)
+- *-fY* allows setint the INIT flag. y can be
+  - 0       Execute prior to display memory and interrupt vector initialization
+  - 1       Execute just before GEMDOS is initialized
+  - 3       Execute prior to boot disk
+  - 5       Application is a Desk Accessory
+  - 6       Application is not a GEM application
+  - 7       Application needs parameters
+- *image_filename* is the filename of the cart image
+- *list of programs to add with optional -b and -f* is a list of ST PRG programs to add to the image, optionally postfixed by a *-b* and/or *-f* to set the parameters for the current file only
+
+More on defaults: The default value for *-b* is $20000, and the default value for *-f* is nothing. Passing *-b* and/or *-f* at the start of the parameter list will override the default values. Passing *-b* and/or *-f* after each program in the list, will override the defaults for that file only.
 
 Caveats (boy, here we go)
-=========================
+-------------------------
 
-- Only use single file PRG programs. Programs that try to load external files will not work.
+- Only use single file PRG programs. Programs that try to load external files will not work
 - TODO: Some sanity checks are performed, but the program is far from bullet proof
-- TODO: Programs that contain BSS should normally not work. For now, we point the bss to the hardcoded address of $20000. This will be user definable in the future. (Unfotunately it doesn't seem possible to do this automatically. If anyone has an idea on how to do this, happy to discuss!)
+- TODO: The BSS start address has to be supplied by user (or accept the default value of $20000). Unfotunately it doesn't seem possible to do this automatically. If anyone has an idea on how to do this, happy to discuss!
 - On BSS: programs that access the BSS using PC relative code will most likely fail
-- TODO: CA_INIT bitfields are not yet available to the user, so we simply add the programs as if they're meant to be run from desktop as GEM applications
 - TODO: Date and Time are still set to bogus vaules
 
+Building
+--------
 
+Use the provided scripts. Or Visual Studio.