Hello,
I have been interested in running openwrt on my Deco S4 devices. In OpenWrt support for Deco S4 - #27 by Mork the FCC-ID was exposed as the same as a Deco M4RV2. I've built custom initramfs images with the default-mac partitioned out, but with an offset ox 0x8 and a size of 0x6, I'm not successfully retrieving the label mac address.
Here is the modified dts, target/linux/ath79/dts/qca9563_tplink_deco-m4r-v1.dts:
I've compared a hexdump of this block to a hexdump from a Deco M4 and found that:
The first 8 are similar, mostly zeroes
The next 8 for the Deco M4 are the label mac address, after this the remainder is FF; for the S4 the next 8 continue to be zeroes.
The next 24 for the S4 appear to be information, but not the label mac address, after this the remainder is FF.
With @bobthebuilder 's help, we found that the stock firmware describes the following default partitions:
partition fs-uboot base 0x00000 size 0x80000
partition product-info base 0x80000 size 0x05000
partition default-mac base 0x85000 size 0x01000
partition device-id base 0x86000 size 0x01000
partition support-list base 0x87000 size 0x10000
partition user-config base 0xa7000 size 0x10000
partition device-config base 0xb7000 size 0x10000
partition group-info base 0xc7000 size 0x10000
partition partition-table base 0xd7000 size 0x02000
partition soft-version base 0xd9000 size 0x10000
partition profile base 0xe9000 size 0x10000
partition default-config base 0xf9000 size 0x10000
partition url-sig base 0x1e0000 size 0x10000
partition radio base 0x1f0000 size 0x10000
partition os-image base 0x200000 size 0x200000
partition file-system base 0x400000 size 0xc00000
When plugging in the device, two lines before Autobooting in 1 seconds, the default mac address is printed to the console in the format of mac[XX-XX-XX-XX-XX-XX], line 28 in this snippet: https://pastebin.com/9tzKPCsc (I've removed the actual address from the linked snippet)
I'm at a loss for next steps. I've looked through the GPL source code but can't find anything that indicates how to successfully load the data out of the default-mac partition for this device.