AR100 driver fails to load its firmware #18

New issue

Closed

opened 2026-08-27 23:22:26 +00:00 by tiagoagueda · 1 comment

tiagoagueda commented

2026-08-27 23:22:26 +00:00

Owner

At every boot:

sunxi-arisc 8100000.coprocessor: Direct firmware load for sun9i-a80-arisc.bin failed with error -2

The driver carries on and works, because it talks to the vendor firmware already resident in
the coprocessor from boot0 — but that means the AR100 state depends on what the vendor
bootloader left behind, which is not something a mainline driver should rely on.

firmware/arisc-v0.0.80.bin in this repo is the board-matched blob, recovered from the eMMC
before it was repartitioned; it exists nowhere else.

Done when

decide whether the driver should load firmware at all, or document that it deliberately
adopts the running instance
if it should load it, install the blob under the expected name and verify the handshake
still completes

At every boot: ``` sunxi-arisc 8100000.coprocessor: Direct firmware load for sun9i-a80-arisc.bin failed with error -2 ``` The driver carries on and works, because it talks to the vendor firmware already resident in the coprocessor from boot0 — but that means the AR100 state depends on what the *vendor* bootloader left behind, which is not something a mainline driver should rely on. `firmware/arisc-v0.0.80.bin` in this repo is the board-matched blob, recovered from the eMMC before it was repartitioned; it exists nowhere else. **Done when** - [ ] decide whether the driver should load firmware at all, or document that it deliberately adopts the running instance - [ ] if it should load it, install the blob under the expected name and verify the handshake still completes

tiagoagueda added the

kernel

P3-normal

labels

2026-08-27 23:22:26 +00:00

tiagoagueda commented

2026-08-28 14:22:10 +00:00

Author

Owner

Resolved 2026-08-28.

The coprocessor firmware now loads and the AR100 comes up on every boot. Two changes were
needed:

the blob is carried in an initramfs, so request_firmware() can succeed before the
rootfs is mounted - populate_rootfs() is a rootfs_initcall and runs before any driver
probes. Setup in tools/initramfs/.
the driver waits 3 s before its first request rather than starting as early as
possible.

That second point is a workaround for a real fault, not a fix, and is tracked on its own as
#47. See 45-a15-cluster-solved.md.

**Resolved 2026-08-28.** The coprocessor firmware now loads and the AR100 comes up on every boot. Two changes were needed: - the blob is carried in an **initramfs**, so `request_firmware()` can succeed before the rootfs is mounted - `populate_rootfs()` is a `rootfs_initcall` and runs before any driver probes. Setup in [tools/initramfs/](../src/branch/main/tools/initramfs/). - the driver **waits 3 s** before its first request rather than starting as early as possible. That second point is a workaround for a real fault, not a fix, and is tracked on its own as #47. See [45-a15-cluster-solved.md](../src/branch/main/45-a15-cluster-solved.md).

tiagoagueda closed this issue

2026-08-28 14:22:10 +00:00