| |
In lugnet.robotics.rcx.legos, Iain McInnes wrote:
> 1) Pass the variable to a function - the first function argument seems to be r0.
I need to access elements of a 2d array. I don't think this is an option for
that. Nevertheless, could you post code that demonstrates this?
> You can easily experiment with this by inspecting the assembler output from gcc.
How do I do that?
> 2) Figure out the assembler idiom for referring to symbols and use that.
???
> 3) I spent a bit of time surfing around the existing code, and there seems to be
> an assembler macro idiom where variables can be pasted directly into the
> assembler. I was too lazy to find the documentation on how to use it, but
> someone might post here to tell you ;)
Hmm... this sounds more like what I'm trying to do. Someone?
#include <conio.h>
#include <unistd.h>
unsigned short total;
int main(int argc, char **argv) {
cputs("hello");
sleep(1);
total = 255;
__asm__("
.text
.align 1
push.w r2
push.w r3
mov.b #0x00,r2h
mov.b #0x08,r2l
verticalxloop:
add.b #1,r2h
cmp.b r2h,r2l
bge loopout
bra verticalxloop
loopout:
mov.b r2h,@_total
pop.w r3
pop.w r2
");
cputw(total);
sleep(1);
cls();
return 0;
}
Here it compiles without an error, but it puts 00FF on the display, rather than
8. Obviously r2h was never actually moved into total at all...
Mike
|
|
Message has 4 Replies:
 | | Re: BrickOS Assembler
|
| (...) Hi Mike, Check out the source for memcpy.c in the C library. It's not immediately clear, but the directives at the end of the __asm__ section beginning with "r" associate the %n macros with the given variables. I'm not sure of the exact syntax (...) (20 years ago, 18-Jan-04, to lugnet.robotics.rcx.legos)
| | | Re: BrickOS Assembler
|
| (...) I recommend compiling with the -gstabs+ option (by modifying the makefile). After your .lx file is generated use "h8300-hms-objdump --disassemble-all --source > my.lst" to get a disassembled file with the C source intermixed.into the file (...) (20 years ago, 19-Jan-04, to lugnet.robotics.rcx.legos)
| | | Re: BrickOS Assembler
|
| (...) In rethinking I think that compiling with the -S option will do what you want. It should create a file with a .s suffix. -S makes the compiler compile, but not assemble. Kevin "YOU ARE A GENIUS!!!!!! you can put that in your sig file!!!" Chris (...) (20 years ago, 19-Jan-04, to lugnet.robotics.rcx.legos)
| | | Re: BrickOS Assembler
|
| (...) One more answer... :-) Mark #include <unistd.h> #include <conio.h> int x = 10; int y = 5; int z; int main() { __asm__(" mov @_x,r0 mov @_y,r1 add r1,r0 mov r0,@_z "); lcd_int(z); msleep(5); return 0; } (20 years ago, 19-Jan-04, to lugnet.robotics.rcx.legos)
|
Message is in Reply To:
| | Re: BrickOS Assembler
|
| Hi, Michael. I had some trouble with getting variables into registers, as well. I can think of three ways: 1) Pass the variable to a function - the first function argument seems to be r0. You can easily experiment with this by inspecting the (...) (20 years ago, 18-Jan-04, to lugnet.robotics.rcx.legos)
|
11 Messages in This Thread:
  
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
This Message and its Replies on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
