I am working at DM6437. Something about CMD file puzzled me.
Take led.prj for example. It consist of two source files: main.c and led.c
main.c
#include "stdio.h"
#include "mk6437.h"
extern Int16 led_test( );
void main( void )
{
/* Initialize BSL */
MK6437_init( );
led_test();
}
led.c
#include "mk6437_gpio.h"
Int16 led_test( )
{
Int16 i;
MK6437_GPIO_init();
MK6437_GPIO_setDir(GPIO00,0);
MK6437_GPIO_setDir(GPIO01,0);
MK6437_GPIO_setDir(GPIO02,0);
MK6437_GPIO_setDir(GPIO03,0);
for(i=0;i<1000;i++)
{
MK6437_GPIO_setOutput(GPIO00,1);
MK6437_GPIO_setOutput(GPIO01,1);
MK6437_GPIO_setOutput(GPIO02,1);
MK6437_GPIO_setOutput(GPIO03,1);
_waitusec( 125000 );
MK6437_GPIO_setOutput(GPIO00,0);
MK6437_GPIO_setOutput(GPIO01,0);
MK6437_GPIO_setOutput(GPIO02,0);
MK6437_GPIO_setOutput(GPIO03,0);
_waitusec( 125000 );
}
return 0;
}
link.cmd
/*
* Linker command file
*/
-l rts64plus.lib
-l ../../lib/mk6437bsl.lib
-stack 0x00001000 /* Stack Size */
-heap 0x00001000 /* Heap Size */
MEMORY
{
L2RAM: o = 0x10800000 l = 0x00020000
DDR2: o = 0x80000000 l = 0x10000000
}
SECTIONS
{
.bss > L2RAM
.cinit > L2RAM
.cio > L2RAM
.const > L2RAM
.data > L2RAM
.far > L2RAM
.stack > DDR2
.switch > L2RAM
.sysmem > L2RAM
.text > DDR2
.ddr2 > DDR2
}
Please note the section in red.
When place the .stack at L2RAM, it works well. LEDs on boards wink at the frequency of 4Hz. But when place the .stack at DDR2, something is wrong. LEDs on boards wink at the frequency of about 1Hz.
At the second case, we can find the contents in “led.map” showing like these:
led.map
******************************************************************************
TMS320C6x COFF Linker PC v6.0.8
******************************************************************************
>> Linked Sun Dec 30 20:49:00 2012
OUTPUT FILE NAME: <./Debug/led.out>
ENTRY POINT SYMBOL: "_c_int00" address: 80002300
MEMORY CONFIGURATION
name origin length used unused attr fill
---------------------- -------- --------- -------- -------- ---- --------
L2RAM 10800000 00020000 00000208 0001fdf8 RWIX
DDR2 80000000 10000000 00003460 0fffcba0 RWIX
SECTION ALLOCATION MAP
output attributes/
section page origin length input sections
-------- ---- ---------- ---------- ----------------
.ddr2 0 80000000 00000000 UNINITIALIZED
.text 0 80000000 00002460
80000000 00000660 mk6437bsl.lib : mk6437_pll.obj (.text)
80000660 00000520 : mk6437.obj (.text)
80000b80 00000460 : mk6437_flash_id.obj (.text)
80000fe0 00000340 : mk6437_i2c.obj (.text)
80001320 000002e0 : mk6437_psc.obj (.text)
80001600 00000240 : mk6437_gpio.obj (.text)
80001840 000001e0 : mk6437_flash.obj (.text)
80001a20 000001c0 : mk6437_ddr.obj (.text)
80001be0 000001a0 rts64plus.lib : mpyd.obj (.text:__mpyd)
80001d80 00000160 led_test.obj (.text)
80001ee0 00000100 rts64plus.lib : frcmpyd.obj (.text:__frcmpyd)
80001fe0 00000100 : exit.obj (.text:_exit)
800020e0 000000e0 : autoinit.obj (.text:__auto_init)
800021c0 000000a0 : fixdu.obj (.text:__fixdu)
80002260 000000a0 : memcpy64.obj (.text:_memcpy)
80002300 00000060 : boot.obj (.text:_c_int00)
80002360 00000040 main.obj (.text)
800023a0 00000040 rts64plus.lib : args_main.obj (.text:__args_main)
800023e0 00000040 : fltud.obj (.text:__fltud)
80002420 00000020 : _lock.obj (.text:__nop)
80002440 00000020 : exit.obj (.text:_abort)
.stack 0 80002460 00001000 UNINITIALIZED
80002460 00000008 rts64plus.lib : boot.obj (.stack)
.cio 0 10800000 00000000 UNINITIALIZED
Obviously, .stack is placed into DDR2 following the instruction in link.cmd. But, by the contents above, only the boot section from rts64plus.lib exits in .stack section.
Would anyone interpret this behavior?
