Preliminary Notes on Porting BFD -------------------------------- The 'host' is the system a tool runs *on*. The 'target' is the system a tool runs *for*, i.e. a tool can read/write the binaries of the target. Porting to a new host --------------------- Pick a name for your host. Call that <host>. (<host> might be sun4, ...) Create a file hosts/<host>.mh. Porting to a new target ----------------------- Pick a name for your target. Call that <target>. Call the name for your CPU architecture <cpu>. You need to create <target>.c and config/<target>.mt, and add a case for it to a case statements in bfd/configure.host and bfd/config.bfd, which associates each canonical host type with a BFD host type (used as the base of the makefile fragment names), and to the table in bfd/configure.in which associates each target vector with the .o files it uses. config/<target>.mt is a Makefile fragment. The following is usually enough: DEFAULT_VECTOR=<target>_vec SELECT_ARCHITECTURES=bfd_<cpu>_arch See the list of cpu types in archures.c, or "ls cpu-*.c". If your architecture is new, you need to add it to the tables in bfd/archures.c, opcodes/configure.in, and binutils/objdump.c. For more information about .mt and .mh files, see config/README. The file <target>.c is the hard part. It implements the bfd_target <target>_vec, which includes pointers to functions that do the actual <target>-specific methods. Porting to a <target> that uses the a.out binary format ------------------------------------------------------- In this case, the include file aout-target.h probaby does most of what you need. The program gen-aout generates <target>.c for you automatically for many a.out systems. Do: make gen-aout ./gen-aout <target> > <target>.c (This only works if you are building on the target ("native"). If you must make a cross-port from scratch, copy the most similar existing file that includes aout-target.h, and fix what is wrong.) Check the parameters in <target>.c, and fix anything that is wrong. (Also let us know about it; perhaps we can improve gen-aout.c.) TARGET_IS_BIG_ENDIAN_P Should be defined if <target> is big-endian. N_HEADER_IN_TEXT(x) See discussion in ../include/aout/aout64.h. BYTES_IN_WORD Number of bytes per word. (Usually 4 but can be 8.) ARCH Number of bits per word. (Usually 32, but can be 64.) ENTRY_CAN_BE_ZERO Define if the extry point (start address of an executable program) can be 0x0. TEXT_START_ADDR The address of the start of the text segemnt in virtual memory. Normally, the same as the entry point. TARGET_PAGE_SIZE SEGMENT_SIZE Usually, the same as the TARGET_PAGE_SIZE. Alignment needed for the data segment. TARGETNAME The name of the target, for run-time lookups. Usually "a.out-<target>"