how does tombstones works in android-kernel

Question

   mkdir /data/tombstones 0771 system system
   symlink /data/tombstones /tombstones
   mkdir /tombstones/mdm 0771 system system
   mkdir /tombstones/modem 0771 system system
   mkdir /tombstones/lpass 0771 system system

   # For firmwares
   mkdir /firmware_radio 0771 system system
   mkdir /firmware_q6 0771 system system
   mkdir /firmware_dsps 0771 system system
   mkdir /vendor 0771 system system
   mkdir /vendor/firmware 0771 system system

   devwait emmc@radio
   mount vfat emmc@radio /firmware_radio ro shortname=lower
   devwait emmc@adsp
   mount vfat emmc@adsp /firmware_q6 ro shortname=lower

   exec /system/bin/sh /system/etc/init.qcom.radio_links.sh
   exec /system/bin/sh /system/etc/init.qcom.q6_links.sh

   mkdir /data/qcks 0770 system system
   mkdir /data/efs 0771 system system

How does the mkdir/tombstones/modem works? I have a htc phone where we have our firmware in different partitions but how it grabs them from the partitions without symlinks? I ported 3.4 kernel for my device (we officially got the 3.0.16) in the 3.4 the kickstart and qcks doesnt support through ttyhsl anymore with the rom I'm porting it use this tombstones way..just wondering how it works...the official ramdisk have the images in this format.

symlink /vendor/firmware/misc_mdm/image/dbl.mbn /vendor/firmware/dbl.mbn

So how does the tombstones works?? I'm a little confused here.