Biktorgj
commented
1 year ago Yes and no,
I mean, I made it boot, got serial, USB, audio working somewhat, and got the ADSP to boot... but with Quectel's ADSP blobs.
There's two show-stopping issues with the BM818, and some other issues that need to be taken into account by anyone who'd want to use it:
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The ADSP firmware blobs included in the firmware are built as a single file that doesn't fit in RAM. In Linux, the files are split into sections and pushed into memory piece by piece. There are some tools to split the files, and they seem to do the splitting just fine, but the ADSP refuses to boot with them. I was able to boot the modem using Quectel's blobs, but that leads to a no-functional-imei and god knows how many EFS issues (this is the reason I haven't released anything)
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The modem has 128Mb of RAM, from which about 80-90 are allocated to the ADSP / Trustzone etc. This leaves me with 30Mb of RAM for both the kernel and the entire userspace, which is very very low. While there's just enough memory to boot, just pushing some files to the flash through ADB makes it exhaust the memory and kills it forcing to reboot.
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You need to repartition the modem and reformat the ADSP firmware partition so it can be mounted by linux and pushed to the adsp. I made some small tools for that, but that means your warranty is totally void from the second you try to flash it
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You need to replace the SBL in the modem, as the factory one will refuse to boot anything but its ThreadX kernel. You can flash Quectel's SBL into place, but this too will void your warranty
I made two tools related to the Broadmobi:
- A tool to backup and restore the IMEI (whenever you flash it, it destroys the EFS area and all the baseband settings and IMEI are gone)
- A tool to change the partition layout
I also have (although so far they're not publicly shared so nobody kills their modems):
- A firmware recovery package, just like with the Quectel repo
- A community firmware package, that boots you into a linux environment with ADB support (but with the issues mentioned above)
I basically ended up at a point where I'm not sure if it's worth to keep trying to make it work, as it'll be only a crippled down version of what's available for the Quectel, and probably prone to a lot of issues due to the low available memory, when you can put a different module in there and call it a day
carlosgonz0
Hi Any progress for the development of the firmware for L5 modem?