Vishal, typing "install" at the "boot: " prompt gives an error ("could not find kernel image: install") to the default one.
After mounting the ISO (first in Windows, then inside an Ubuntu VM), I looked inside its "isolinux" directory. Despite being the same size (366 bytes), my ISO's isolinux.cfg file is empty. This file, seen on one of the mirrors, contains the following text:
default linux
prompt 1
timeout 600
display boot.msg
F1 boot.msg
F2 options.msg
F3 general.msg
F4 param.msg
F5 rescue.msg
label linux
kernel vmlinuz
append initrd=initrd.img
label text
kernel vmlinuz
append initrd=initrd.img text
label ks
kernel vmlinuz
append ks initrd=initrd.img
label local
localboot 1
label memtest86
kernel memtest
append -
Update: I typed "vmlinuz" (as the isolinux.cfg on the mirror suggested), and a kernel began initializing! Unfortunately, a kernel panic is reported after a few seconds: "unable to mount root fs on unknown block...."
ISO mili bhi toh gadbad! I'll try to replace the contents of /isolinux and then report back to you all.