How to have RAM/HEAP in page 0 and ROM/CODE in page 1?

[bengalack]

I'm on z80/MSX and try to have RAM in 0x0000-0x3FFF and ROM in 0x4000-07FFF

I'm on SDCC 4.2 and I was trying this:
sdcc --code-loc 0x4000 --data-loc 0x0000 -mz80 --no-std-crt0 empty_reverse_crt.rel ...

I thought I had to place RAM before ROM in my CRT, so my empty_reverse_crt.s is like ( I have barely no idea what I'm doing here):

.area _HEADER (ABS)
.area _HEAP
.area _DATA
.area _HOME
.area _GSINIT
.area _GSFINAL
.area _INITIALIZER
.area _ROMDATA
.area _INITIALIZED
.area _CODE

Also, there is no code in the CRT, no use of initializers.

But, still, RAM is placed AFTER my code. Any tips?

[Janko Stamenović]

My example needed data-loc non-zero: so --data-loc 0x1 worked as I wanted, as it was zero there, not. Also, just tangential: later, take care about the order of other areas later (that is relevant only if your compiled code uses them and you need specific placement, otherwise, you can ignore that).

[bengalack]

Thank you so much! will test ASAP when back at the computer.

[bengalack]

[bengalack]

Yes. Great. It works very well! No change from my normal crt.s file was needed either: no need to place .area _DATA or _HEAP in front of _CODE, it seems.