From aa2289c2a3faf0f198e47943dcb29e0c16223be8 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 3 May 1999 07:29:11 +0000 Subject: Initial revision --- bfd/PORTING | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 bfd/PORTING (limited to 'bfd/PORTING') diff --git a/bfd/PORTING b/bfd/PORTING new file mode 100644 index 0000000000..c8bfd77b96 --- /dev/null +++ b/bfd/PORTING @@ -0,0 +1,83 @@ + 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 . +( might be sun4, ...) +Create a file hosts/.mh. + +Porting to a new target +----------------------- +Pick a name for your target. Call that . +Call the name for your CPU architecture . +You need to create .c and config/.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/.mt is a Makefile fragment. +The following is usually enough: +DEFAULT_VECTOR=_vec +SELECT_ARCHITECTURES=bfd__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 .c is the hard part. It implements the +bfd_target _vec, which includes pointers to +functions that do the actual -specific methods. + +Porting to a 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 .c for +you automatically for many a.out systems. Do: + make gen-aout + ./gen-aout > .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 .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 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-" -- cgit v1.2.1