[Etherboot-developers] undionly.kpxe suspended in main.c

[justhechuang <jus...@16...>]

Hi,
 
I tried the latest gPXE bootloader gpxe-0.9.5 and encounted a problem:
 
The bininary file undionly.kpxe works OK, but I am a little dispointed about the startup() process in main() of core/main.c, which takes 4 seconds or so to complete on a physical machine. Yet this time delay is milliseconds only on a VMWare virtual machine. 
 
So I tracked down startup() and eventually found out that this time delay is in undinet_call() of arch/i386/drivers/net/undinet.c. Exactly speaking, this cause belongs to the following code when the parameter function is specified as PXENV_UNDI_INITIALIZE:
 
__asm__ __volatile__ ( REAL_CODE ( "pushw %%es\n\t"
        "pushw %%di\n\t"
        "pushw %%bx\n\t"
        "lcall *%c3\n\t"
        "addw $6, %%sp\n\t" )
          : "=a" ( exit ), "=b" ( discard_b ),
            "=D" ( discard_D )
          : "p" ( __from_data16 ( &undinet_entry_point )),
            "b" ( function ),
            "D" ( __from_data16 ( &undinet_params ) )
          : "ecx", "edx", "esi", "ebp" );
 
 
It is a pity that I know little about assemble language, hope that somebody can help me.
My questions are:
(1)What does these codes do with PXENV_UNDI_INITIALIZE ?
(2)Why the time delay of a physical machine is different from VMWare? (4 seconds compared with milliseconds)
(3)Is it possible to be correlated to the network devices, such as a switch or a hub?
 
Thanks in advance!
soforth.