How can I use the full flash available on AsiaRF AWM002 evaluation board

Hi!

I have AWM002 evaluation board with 32MB of RAM and 16MB of flash that I am using as 4G router. There are two options of firmware for this router:
awm002-evb-8M-squashfs-sysupgrade.bin
awm002-evb-4M-squashfs-sysupgrade.bin

I have flased 8M version and router saw only 8MB of flash and had only 3MB (82%) available for additional packages. How can I get full flash capacity?

I have another such router with Chaos Calmer 15.05. It shows 8MB (66%) available.

@Mishunja, welcome to the community!

Compile a firmware for the 32 MB board.

Thank you, Ileachii.
Please advise a parameter in config that changes flash size.

Is it possible to change mtd config instead of compliling from souce?
I compared kernel log of Openwrt 15.05 and 18.06

[    0.540000] m25p80 spi32766.0: found mx25l12805d, expected mx25l6405d
[    0.550000] m25p80 spi32766.0: mx25l12805d (16384 Kbytes)
[    0.560000] 4 ofpart partitions found on MTD device spi32766.0
[    0.570000] Creating 4 MTD partitions on "spi32766.0":
[    0.580000] 0x000000000000-0x000000030000 : "u-boot"
[    0.590000] 0x000000030000-0x000000040000 : "u-boot-env"
[    0.610000] 0x000000040000-0x000000050000 : "factory"
[    0.620000] 0x000000050000-0x000002000000 : "firmware"
[    0.630000] mtd: partition "firmware" extends beyond the end of device "spi32766.0" -- size truncated to 0xfb0000
[    0.800000] 2 uimage-fw partitions found on MTD device firmware
[    0.810000] 0x000000050000-0x00000015097b : "kernel"
[    0.820000] 0x00000015097b-0x000001000000 : "rootfs"
[    0.830000] mtd: device 5 (rootfs) set to be root filesystem
[    0.840000] 1 squashfs-split partitions found on MTD device rootfs
[    0.860000] 0x000000380000-0x000001000000 : "rootfs_data"
[    0.550000] m25p80 spi32766.0: mx25l12805d (16384 Kbytes)
[    0.560000] 4 ofpart partitions found on MTD device spi32766.0
[    0.570000] Creating 4 MTD partitions on "spi32766.0":
[    0.580000] 0x000000000000-0x000000030000 : "u-boot"
[    0.590000] 0x000000030000-0x000000040000 : "u-boot-env"
[    0.610000] 0x000000040000-0x000000050000 : "factory"
[    0.620000] 0x000000050000-0x000002000000 : "firmware"
[    0.630000] mtd: partition "firmware" extends beyond the end of device "spi32766.0" -- size truncated to 0xfb0000
[    0.800000] 2 uimage-fw partitions found on MTD device firmware
[    0.810000] 0x000000050000-0x00000015097b : "kernel"
[    0.820000] 0x00000015097b-0x000001000000 : "rootfs"
[    0.830000] mtd: device 5 (rootfs) set to be root filesystem
[    0.840000] 1 squashfs-split partitions found on MTD device rootfs
[    0.860000] 0x000000380000-0x000001000000 : "rootfs_data"```