i have solved this problem.
My hunch that the problem is due to the ramdisk init file was partially right.
The solution indeed required modifying the ramdisk but it wasn't the init file to be exact. It was the fstab configuration file. In my case, where I am developing on sabre-sdb(imx6quad) Lollipop 5.1 BSP, the ramdisk has a file named 'fstab.freescale'. Opening the fstab file for the problematic image ramdisk, the contents were as below:
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# Android fstab file.
#<src> <mnt_point> <type> <mnt_flags and options> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK
/devices/soc0/soc.0/2100000.aips-bus/2198000.usdhc/mmc_host /mnt/media_rw/extsd vfat defaults voldmanaged=extsd:auto
/devices/soc0/soc.0/2100000.aips-bus/2184000.usb/ci_hdrc.0 /mnt/media_rw/udisk vfat defaults voldmanaged=udisk:auto
/dev/block/mmcblk3p5 /system ext4 ro,barrier=1 wait,verify
/dev/block/mmcblk3p4 /data ext4 nosuid,nodev,nodiratime,noatime,nomblk_io_submit,noauto_da_alloc,errors=panic wait,encryptable=/dev/block/mmcblk3p9
/dev/block/mmcblk3p6 /cache ext4 nosuid,nodev,nomblk_io_submit wait
/dev/block/mmcblk3p7 /device ext4 ro,nosuid,nodev wait
/dev/block/mmcblk3p1 /boot emmc defaults defaults
/dev/block/mmcblk3p2 /recovery emmc defaults defaults
/dev/block/mmcblk3p8 /misc emmc defaults defaults
/dev/block/mmcblk3boot0 /bootloader emmc defaults defaults
/dev/block/zram0 none swap defaults zramsize=314572800
========================================
In comparision, opening the same fstab.freescale file in the functional ramdisk, the contents were as below:
====================================
# Android fstab file.
#<src> <mnt_point> <type> <mnt_flags and options> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK
/devices/soc0/soc.0/2100000.aips-bus/2194000.usdhc/mmc_host /mnt/media_rw/extsd vfat defaults voldmanaged=extsd:auto
/devices/soc0/soc.0/2100000.aips-bus/2184000.usb/ci_hdrc.0 /mnt/media_rw/udisk vfat defaults voldmanaged=udisk:auto
/dev/block/mmcblk2p5 /system ext4 ro,barrier=1 wait,verify
/dev/block/mmcblk2p4 /data ext4 nosuid,nodev,nodiratime,noatime,nomblk_io_submit,noauto_da_alloc,errors=panic wait,encryptable=/dev/block/mmcblk2p9
/dev/block/mmcblk2p6 /cache ext4 nosuid,nodev,nomblk_io_submit wait
/dev/block/mmcblk2p7 /device ext4 ro,nosuid,nodev wait
/dev/block/mmcblk2p1 /boot emmc defaults defaults
/dev/block/mmcblk2p2 /recovery emmc defaults defaults
/dev/block/mmcblk2p8 /misc emmc defaults defaults
/dev/block/mmcblk2 /bootloader emmc defaults defaults
/dev/block/zram0 none swap defaults zramsize=314572800
=====================================
As you can see the problematic version has been all set to 'mmcblk3' which is identical to the log retrieved from the log, which is shown in the main post.
Thus what I had to do was switch the problematic fstab.freescale file with the functional version.
I repacked the image(kernel+ramdisk+dtb) with mkbootimage (be sure to properly set the boot addresses for each), and checked that it works!