From: Groepaz (groepaz_at_gmx.net)
Date: 2003-09-24 06:16:50
mmmh... i was wondering if this is possible...
in one project i am using a real lot of macros for readability, but while
thats nice for actual coding, it can be a major drawback when debugging and
additionally, it makes any form of automatic optimizing (a peephole run would
make a lot of sence here) kindof impossible.
so is there a possibility to make ca65 ouput the "preprocessed" assembler
code? something like the list-file, but in a format that can be assembled by
ca65 again?
tjam, then for a totally different thingy.... a compiler option that would
make the compiler threat "int" as "signed long" (ie 32 vs 16 bit ints) could
be really useful when you are porting code and are wondering why the hell it
doesnt work as intended...if it changes behaviour with 32 bit ints, you know
whats the problem atleast :=P (no idea how deep the 16bit thing is hardcoded
into the compiler though, making it an option might be anything from easy to
impossible depending on the implementation :=P)
gpz
ps...oh and i noticed another thing....on your FAQ page there is a big
paragraph about the .org directive and the difference between ca65/ld65 and
other simplier assemblers, but yet it doesnt tell how to exactly "emulate"
their simplier behaviour (and your suggestion is somewhat misleading too
IMHO) .... since this is something ppl tend to ask me every now and then, why
not add this snippet ... :o)
Q: I just want to use ca65 the same way i was using the infamous TASS on the
C64 before, i dont need the additional features provided by the linker - so
how to do this?
A: You need to use some of the ca65 emulation features to simulate the
behaviour of such simple assemblers, for example like this:
1) prepare your sourcecode like this:
; if you want TASS style labels without colons
.feature labels_without_colons
; if you want TASS style character constants ("a" instead of the default 'a')
.feature loose_char_term
.word *+2 ; the cbm load address
[yourcode here]
notice that the two emulation features are mostly useful for porting sources
originally written in/for TASS, they are not needed for the actual "simple
assembler operation" and are not recommended if you are writing new code from
scratch.
2) replace all programcounter assignments (which are not possible in ca65 by
default, and the respective emulation feature works different from what you'd
expect too) by another way to skip to another memory location, for example
the .res directive
; *=$2000
.res $2000-* ; reserve memory up to $2000
notice that other than the original TASS, ca65 can never move the
programmcounter backwards - think of it as if you are assembling to disc with
TASS.
3) conditional assembly (.ifeq/.endif/.goto etc) must be rewritten to match
ca65 syntax - most importantly notice that due to the lack of .goto
everything involving loops must be replaced by .repeat (consult the ca65 docs
for more)
4) to assemble code to a different address than it is executed at, use the
.org directive instead of .offs-constructs
.org $1800
[floppy code here]
.reloc ; back to normal
5) then assemble like this:
cl65 --start-addr 0x0ffe -t none myprog.s -o myprog.prg
notice that you need to use the actual start address minus two, since two
bytes are used for the cbm loadaddress
....
mmmh, maybe rephrase it a bit, but other than that it should give those a clue
who come from other assemblers to ca65 :) (and yeah, its actually possible to
do without making any linker configs :))
oh and in ca65 docs you suggest using "pc_assignment" for emulating xa65...
are you sure about this? in TASS (and several crossassembler that are clones
of it) atleast a programmcounter assignment really moves the programcounter
(ie, both run AND load address) and not only the (run-)address (eh tricky
terminology here...so whats the correct term for "the address we are
assembling to" and "the address we are currently assembling at" ? :=P)
so...not sure if the "progcount assignment means .org" is really accurate
.... TASS and derivates use .offs for what is .org in ca65, and i _think_
there is a simelar thing in xa65 too.
tjam...that reminds me of the "ca65 vs other assemblers" table i have started
once...maybe i should bring it into a useable state too :=P (can anyone
recommend a way to layout a large table? its currently in html, but not
really useful due to its size - lots of scrolling involved etc :/)
mmhz...that became much more text than intended :=P so...lets stop :=P
gpz
----------------------------------------------------------------------
To unsubscribe from the list send mail to majordomo_at_musoftware.de with
the string "unsubscribe cc65" in the body(!) of the mail.
This archive was generated by hypermail 2.1.3 : 2003-09-24 06:22:19 CEST