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Great help, mr, thank you.
Regarding my initial question, I have found out that it is in fact possible to define symbols in C that
can be used in asm, like this:
#define PARTICULAR_OPTION 1
#if PARTICULAR_OPTION
#pragma asm "PARTICULAR_OPTION equ 1"
#else
#pragma asm "PARTICULAR_OPTION equ 0"
#endif
#pragma asm "xdef PARTICULAR_OPTION"
Then in asm
xref PARTICULAR_OPTION
ld r0,#PARTICULAR_OPTION
To get true conditional assembly I would prefer this method:
#define PARTICULAR_OPTION 1
#if PARTICULAR_OPTION
#pragma asm "PARTICULAR_OPTION" // becomes a program label
#pragma asm "xdef PARTICULAR_OPTION"
#endif
and in asm:
xref PARTICULAR_OPTION
ifdef PARTICULAR_OPTION
ld r0,#1234
else
ld r0,#5678
endif
To my great disappointment, however, the ifdef directive does not work properly on the assembler,
because it treats any xref'ed symbol as being defined, so the above will always end up with r0 = 1234.
With my current project settings, C puts variables in a segment called FAR_BSS. So I did this in asm:
segment FAR_BSS
_my_asm_variable ds 4
xdef _my_asm_variable
Then in C:
extern unsigned int my_asm_variable;
After rebuild, this variable had the same address in the asm listing and the C listing.
It works in the reverse direction too. In C:
static unsigned int my_c_variable;
#pragma asm "xdef _my_c_variable"
and in asm:
xref _my_c_variable
ld r0,_my_c_variable
They got the same address also.
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