From: Oleg Uzenkov <o.uzenkov@unicore.co.ua>
To: Edgar Grimberg <edgar.grimberg@gmail.com>,
Rainer Arndt <arndt@ibehs.de>
Cc: eCos Discussion <ecos-discuss@sourceware.org>
Subject: Re: [ECOS] small custom bootloader to start an app stored in flash
Date: Thu, 23 Oct 2014 15:03:00 -0000 [thread overview]
Message-ID: <544918B9.7000601@unicore.co.ua> (raw)
In-Reply-To: <CAPrjMDCdT9ddPowRvQmaKh396tYwt7yWLzKNQB+83Asi0f71jw@mail.gmail.com>
Hi again,
At last got some progress! :-)
The jump from the bootloader now works (but with one minor problem. plz
see below)
I found that the problem was caused by optimisation.
(and it was dumb of me not to pay attention to a warning: optimization
may eliminate reads and/or writes to register variables)
I should have not used -O option when I use a register variable.
Here is bootloader's code:
#define HAL_PLF_ARCH_GETRESETVECTOR(__reset,__vector) \
{ \
__reset = *((unsigned long*)(__vector+4)); \
register volatile CYG_ADDRESS __stack_ptr asm("sp");\
__stack_ptr = (*((unsigned long*)(__vector))); \
}
static volatile unsigned long exec;
int main (void) {
diag_printf( "JUMP\n" );
HAL_PLF_ARCH_GETRESETVECTOR(exec, 0x08020000);
((void (*)(void))exec)();
while (1);
return 0;
}
Here is app's code:
int main (void) {
diag_printf( "HELLO1\n" );
diag_printf( "HELLO2\n" );
while (1);
return 0;
}
But there is still some minor problem:
Please have a look at the terminal output:
JUMPC!â11=â
HELLO2
Notice that instead of "HELLO1" a garbage (C!â11=â) is printed out.
Where as the next HELLO2 is ok.
It is either something related to diag_print() that was not initialised
properly.
or may be something to do with thumb mode on Cortex-4?
here:
$ arm-none-eabi-nm -n app.elf | grep hal_reset_vsr
08020984 T hal_reset_vsr
where as exec is (08020984+1):
(gdb) next
28 ((void (*)(void))exec)();
(gdb) print/x exec
$3 = 0x8020985
any ideas?
Thank you very much for you help!!!
Oleg
--
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next prev parent reply other threads:[~2014-10-23 15:03 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-21 8:27 Oleg Uzenkov
2014-10-21 11:02 ` Gary Thomas
2014-10-21 13:25 ` Edgar Grimberg
[not found] ` <CAPrjMDAi=cqTSQ-d-c9FF53W-c6=v0j8rzSLQfuTcBQUY43Zpw@mail.gmail.com>
2014-10-22 11:08 ` Oleg Uzenkov
2014-10-22 13:17 ` Edgar Grimberg
2014-10-22 14:40 ` Oleg Uzenkov
2014-10-23 9:55 ` Edgar Grimberg
2014-10-23 12:53 ` Edgar Grimberg
2014-10-23 15:03 ` Oleg Uzenkov [this message]
2014-10-23 19:25 ` Rainer Arndt
2014-10-23 21:21 ` Sergei Gavrikov
2014-10-24 7:44 ` Oleg Uzenkov
2014-10-24 8:36 ` Sergei Gavrikov
2014-10-24 9:13 ` Oleg Uzenkov
2014-10-24 9:13 ` Sergei Gavrikov
2014-10-22 19:01 ` Rainer Arndt
2014-10-23 11:50 ` Oleg Uzenkov
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