view leo-obj/README @ 215:d69f7512e3c1

Pirelli: documented and verified the checksum scheme used for the factory block
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 25 Dec 2016 23:48:16 +0000
parents 006d6de4ec6b
children
line wrap: on
line source

TI's TCS211 aka Leonardo firmware is a mixture of C sources and linkable object
modules (packaged into archive libraries) in the COFF format used by TI's TMS470
compiler toolchain.  One of the goals of the FreeCalypso project is to transform
this firmware into full C source by analyzing the COFF object blobs with a tool
that groks the symbolic information present therein, then replacing each blob
either with a matching source piece from another TI firmware leak (e.g., the one
in ftp.ifctf.org:/pub/GSM/LoCosto) or with newly written C code that exports
the same functions and global variables etc, with logic inside matching the
disassembly of the original.

The present directory tree holds the just-described project - running 'make'
here will first build the tiobjd tool, then run this tool on a bunch of TI's
objects, applying some hand-added disassembly hints in many cases.

It is noteworthy that there are two kinds of COFF object blobs present in the
TCS211 semi-src, with respect to the amount of symbolic information present
therein.  The objects contained in the binary libraries under
g23m/__out__/gsm_<blah>/lib have just the minimal amount of symbolic info
needed in order for these objects to be relocatable and linkable, whereas the
objects in the GPF libraries under gpf/LIB exhibit much richer "-g"-style
symbolic information.  Our tiobjd tool makes use of whatever symbolic info is
present.