[syslinux] syslinux-6.03 failed to boot ESXI 6.7

[luckydog xf]

Hello, list,

   I'm buiding syslinux6.3 with ESXI6.7, but it says,

  * failed to load COM32 File
http://172.16.234.112/images/esxi67/mboot.c32*

Here is my config:

------------------

label esxi
  menu label ESXI-6.7 ^Installer
  kernel http://172.16.234.112/images/esxi67/mboot.c32
  append -c http://172.16.234.112/images/esxi67/boot.cfg
--------------------

Seeing from http access log, mboot.c32 was loading successfully.
172.16.235.99 - - [12/Mar/2019:17:59:15 +0800] "GET
/images/esxi67/mboot.c32 HTTP/1.0" 200 90088 "-" "Syslinux/6.03"

-------------------------

I read from Common problems of docs, and rename mboot.c32 to mboot
accordingly, it raises the same error.

But the way, where is the correct way of booting from local drive?

* localboot 0X80 * or -1 does not work.

Thanks,