cleverca22

3 ms·

1.
by cleverca22 4y ago
the rpi-open-firmware codebase is going the route of doing as little as possible on the VPU, and giving the arm control fairly early i found that a bit limiting, with the lack of threads/drivers/modularity thats why i ported littl
2.
by cleverca22 4y ago
yep, thats why ive been focusing a lot on porting linux drivers over to little-kernel on the vpu, and getting things working without linux https://www.youtube.com/watch?v=l7lIewA9fm4 is an example of a VPU accelerated mande
3.
by cleverca22 4y ago
some peripherals like the dram controller are rigged up so the arm can never control them others like the 2d core default to the same mode, but can be re-configured to allow the arm to control it there may be more peripherals that behave th
4.
by cleverca22 4y ago
libcamera also supports the rpi and moves all of that control loop stuff into linux userland, so you would think there are no secrets left but the actual register writes to drive the ISP are still in the blob, and libcamera is just telling
5.
by cleverca22 4y ago
i have seen evidence that RPF cant properly modify some of the h264 blobs so they are instead patching the blob at runtime
6.
by cleverca22 5y ago
lk-overlay contains many different projects using the vc4-stage1, vc4-stage2, and rpi2-test projects together, you can do the entire boot chain (dram init and loading linux) using open source code other projects act as demo's or tests
7.
by cleverca22 6y ago
https://www.raspberrypi.org/forums/viewtopic.php?p=576143 > a China knockoff version of R-Pi camera board > It's happened to the company I work with, they were marketing a cheap copy of our consumer electron
8.
by cleverca22 6y ago
yeah, you can either do baremetal arm under the official firmware (quad-core arm, up to 1.8ghz depending on the model) or you can do baremetal VPU and skip the firmware entirely 500mhz dual-core VPU 128kb of L2 cache for both code and data
9.
by cleverca22 6y ago
from what ive heard, the RSA support is present, but disabled on the pi4 boards my theory is that its only there to protect the non-rpi customers, now that the hmac-sha1 layer has been cracked