Hello World,

I am working on a pretty old ARM system (CLPS7500). I have tried to compile MAD and execute it on CLPS7500 (madplay) I found the decoder does not work properly. It gives not sound at all. The same executable runs perfectly on other ARM system. Can someone tells me what is happening?

Has anyone ported MAD to older ARM system? If I am about to do so myself, can someone points out where the problem is? This may save me a lot of time.

Yick

Hi Rob,

I mean the output samples are wrong (but not all zeros).

That is what I did:

I ran the following command in 3 different systems:

madplay --output=raw:/tmp/eb7312 xxx.mp3 in EP7312 madplay --output=raw:/tmp/clps7500 xxx.mp3 in CLPS7500 madplay --output=raw:/tmp/pc xxx.mp3 in PC

The madplay in EP7312 and CLPS7500 are the same. I have compiled it using the following options:

CC=arm-linux-gcc RANLIB=arm-linux-ranlib LD=arm-linux-ld ./configure --enable-speed --disable-debugging --enable-fpm=arm --enable-aso --target=arm make

Then I do: cat pc > /dev/dsp in PC cat clps7500 > /dev/dsp in PC cat eb7312 > /dev/dsp in PC

The quality of pc file is the best. Then eb7312 file is fair, but I hear no sound from the file clps7500.

I have checked the contents of the files and they are all different.

Please kindly indicates me some clues to fix the problem

Yick Hong Kong, China

Do you mean the output samples are wrong (all zero perhaps)? Can you compare the output using -o with the output from another ARM system that works?

Or do you mean the sound module isn't working? Are there other programs on the system which do produce sound?

-rob

armccurdy@yahoo.co.uk wrote:

Yick,

...

I ran the following command in 3 different systems:

madplay --output=raw:/tmp/clps7500 xxx.mp3 in CLPS7500

As far as I know, the ARM7 core in the ARM7500FE processor lacks the enhanced multiply instructions of the later ARM7TDMI core which the ARM assembler routines and multiply macros rely on. Worse still, I don't think an undefined instruction exception is generated.

The only multiply instructions available are MUL and MLA, which both return only the lower 32bits of a 32x32 multiply.

To run MAD on an ARM7500FE, try configuring MAD with --disable-aso and --enable-fpm=default. Then compile with gcc using -mcpu=arm7. The result will be fairly low quality, and very slow, but it should be music.

Good luck... :-)

Andre

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Dear Sir,

I have tried what you said and it works!!! but I like to try improving the decoding..

I would like to implement the 32bits x 32 bit instrution using macro: but I am not familiar with assembly code in gcc. I have written the following very simple function, it compiles successfully. However when I run it, I got segmentation fault....

In the C program side, I wrote (main.c):

--------------------------------------------------------------------------------------- #include <stdio.h> #include <stdlib.h>

long mul(long a, long b, long *c, long *d);

int main(int argc, char **argv) { long a, b, c, d;

a=atol(argv[1]); b=atol(argv[2]);

mul(a, b, &c, &d); fprintf(stderr, "%ld %ld\n", a, b); fprintf(stderr, "%lx %lx %lx %lx\n", a, b, c, d); } -------------------------------------------------------------------------------------------

The mul fuction is written in Assembly (mul.S) as follow: (not finished Yet, just simple function doing nothing) ---------------------------------------------------------------------- .text .align

.global mul .global _mul

mul: _mul: stmdb sp!, {r4-r12, lr} @ push everything onto the stack... adr r0, Rm_backup str r1, [r0] ldmia sp!, {r4-r12, pc} @ return with <lr> destroyed

Rm_backup: .word 12 Rs_backup: .word 12 ip_backup: .word 12

.end ---------------------------------------------------------------------------

The Makefile is --------------------------------------------------------------------------- CC=arm-linux-gcc CFLAGS= -Wall -O \ -fforce-mem -fforce-addr -fthread-jumps -fcse-follow-jumps \ -fcse-skip-blocks -fexpensive-optimizations -fregmove\ -fschedule-insns2 -fstrength-reduce -finline-functions\ -fomit-frame-pointer

all: main

main: mul.o main.o $(CC) $(CFLAGS) -o main mul.o main.o

main.o: main.c $(CC) $(CFLAGS) -c main.c -o main.o

mul.o: mul.S $(CC) $(CFLAGS) -c mul.S -o mul.o -------------------------------------------------------------------------------

The intention in mul.S is to declare 3 local variables, Rm_backup, Rs_backup and ip_backup and store value of r1 into it but when I run, I got segmentatin fault immediately. Why???

Can you tell me how can I implement the following C functions in ARM assembly language:

1) long mul(long a, long b, long *c, long *d) { long e=3;

*c=a+e; *d=*c; return *d; }

2) long mul(long a) { c=a; // c is global variable return d; // d is global variable... }

Yick