RTEMS Intel i386 Applications Supplement
As discussed above, the call instruction does not automatically save any registers. RTEMS uses the registers EAX, ECX, and EDX as scratch registers. These registers are not preserved by RTEMS directives therefore, the contents of these registers should not be assumed upon return from any RTEMS directive.
RTEMS Intel i386 Applications Supplement
Copyright © 1988-2000 OAR Corporation