questions about port rtems to ARM CPU am1707?

[郑小军]

 Dear all:
I am a newbie to rtems, i'm porting rtems to TI's ARM arm1707, now rtems can
run on my board, but i still have some questions about rtems.
1. vector address? in file cpukit\score\cpu\arm\cpu.c
function _CPU_ISR_install_vector() install vector at address 0x0,but i need
to install at high address,does rtems provide a standard way to do it? i do
not find a standard way to do it, so i modify the file directly, but i think
it is not a good way.
2. about task context switch time,
i measure the time use this way:
task1()
{
for(;;)
{
wait at a message queue;
toggle gpio;
}
}
 Init()
{
...
for(;;)
{
send message;
toggle gpio;
sleep;
}
}
the time is about 27us, i have read a title about the time, but it gives the
time is about 2~3us.Did I do something wrong?
     3.how to measure the interrupt context switch time?


 English is not my native language, hope you can understand what i say. And
give me some advice about English. thank you .
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/users/attachments/20110815/7b6bc6b2/attachment.html>