Raspberry Pi camera under NetBSD current

[Dave Tyson <dtyson%anduin.org.uk@localhost>]

I have been trying to get the raspberry pi camera to work on a model B under a 
recent current snapshot. 

 NetBSD 9.99.88 (RPI) #0: Fri Sep 24 18:47:29 UTC 2021
 mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/evbarm/compile/RPI

As standard booting off the sdcard works fine with the default config.txt,
but to use the camera you need to modify this to add  start_x=1 and set the 
gpu mem to 128.  With the changed options you need different microcode files 
in the /boot partition start_x.elf and fixup_x.dat. NetBSD doesn't supply 
these, but I pulled versions from the git repository.

The problem is that the system boots, but fails to attach the sdcard and thus 
cannot find root, Looking at the dmesg's from the two boots (screen shots for 
the failing one) it seems something goes wrong, but the error is poorly 
reported, A sort of diff between the dmesgs shows:

 -[     1.000000] total memory = 384 MB
 -[     1.000000] avail memory = 366 MB
+[     1.000000] total memory = 128 MB
+[     1.000000] avail memory = 115 MB

 -[     1.000000] genfb0: framebuffer at 0x5e6fa000, size 1280x1024, depth 32, 
stride 5120
+[     1.000000] genfb0: framebuffer at 0x4e6fa000, size 1280x1024, depth 32, 
stride 5120

 [     1.180396] sdmmc0: direct I/O error 5, r=6 p=0xc8733f14 write
-[     1.230495] sdmmc0: SD card status: 4-bit, C6
-[     1.230495] ld0 at sdmmc0: <0x03:0x5344:SU08G:0x80:0x020d4db4:0x0c5>
-[     1.230495] ld0: 7580 MB, 3850 cyl, 64 head, 63 sec, 512 bytes/sect x 
15523840 sectors
-[     1.240524] ld0: 4-bit width, High-Speed/SDR25, 50.000 MHz
+                sdmmc0: autoconfiguration error: can't get SD status 5
+                sdmmc0: autoconfiguration error: mem init failed
+                sdmmc0: autoconfiguration error: init failed 

At first I thought the sdmmc0: direct I/O error 5, r=6 p=0xc8733f14 write
message was the problem, but that appears on the successful boot as well.

Irritatingly FreeBSD seems to work OK with the camera - but I really would 
prefer NetBSD.

I can compile a kernel with some debugging for the sdcard, but thought others 
may have run into this problem....

Cheers,
Dave