First and foremost this application note draws on techniques described in Embecosm Application Notes 3-6 [7] [8] [9] [10]. These should be used as the primary source of additional information.
Verilator has its own website (www.veripool.org), providing guidance for downloading, installing and using the tool. In particular this application note should be read in conjunction with the Verilator user guide.
SystemC is defined by IEEE standard 1666, and the standardization documents are the ultimate reference. The SystemC standard [14] is a free PDF download (a novelty for the IEEE). The open source reference implementation from OSCI includes an introductory tutorial.
JTAG is also an IEEE standard (1149.1), and the standardization document is the ultimate reference. Unlike the SystemC standard, the JTAG standard [16] costs money. The Texas Instruments JTAG primer [15] is a useful free alternative.
The main user guide for GDB [21] provides a great deal of context about how GDB is intended to work. The GDB Internals document [12] is essential reading before and during any porting exercise. It is not complete, nor is it always up to date, but it provides the first place to look for explanation of what a particular function does.
The files making up the examples used in this application noted are comprehensively commented, and can be processed with Doxygen [23]. Each class, member and method's behavior, parameters and return value is described.