PR 252541: Early kernel panic on RPi4B (Too many early devmatch mappings)

[Mark Millard]

[I've cut the history.]

I've tried a from-scratch build via the script:

# more ~/sys_build_scripts.amd64-host/make-aarch64-debug-clang-default_config-amd64-host.sh
kldload -n filemon && \
script ~/sys_typescripts/typescript_make_aarch64_debug_clang_default_config-amd64-host-$(date +%Y-%m-%d:%H:%M:%S) \
env __MAKE_CONF=/dev/null SRCCONF=/dev/null SRC_ENV_CONF=/dev/null TARGET=arm64 TARGET_ARCH=aarch64 \
WITH_META_MODE=yes \
MAKEOBJDIRPREFIX="/usr/obj/aarch64dbg_default_config_clang/arm64.aarch64" \
make $*

on my existing source context ( 19cca0b9613d
with CommitDate 2021-01-09 16:21:33 -0800 
based ):

# ~/fbsd-based-on-what-freebsd-main.sh mm-src
19cca0b9613d7c3058e41baf0204245119732235
CommitDate: 2021-01-09 16:21:33 -0800
5d333ee67ac3 19cca0b9613d (HEAD -> mm-src) mm-src snapshot for mm's patched build in git context.

So defaults but for TARGET, TARGET_ARCH, WITH_META_MODE, and
MAKEOBJDIRPREFIX . WITH_META_MODE should not matter for a
from-scratch build as far as I know.

This is still a cross-build context. I used the 3 commands:

~/sys_build_scripts.amd64-host/make-aarch64-debug-clang-default_config-amd64-host.sh -j32 kernel-toolchain

~/sys_build_scripts.amd64-host/make-aarch64-debug-clang-default_config-amd64-host.sh -j32 buildkernel

~/sys_build_scripts.amd64-host/make-aarch64-debug-clang-default_config-amd64-host.sh -j32 installkernel DESTDIR=/usr/obj/DESTDIRs/clang-aarch64-installkernel-dbg-default_config

(I'll avoid documenting copying to the RPi4B /boot/kernel/ and such.)

It still failed to boot, with:

. . .
Hit [Enter] to boot immediately, or any other key for command prompt.
Booting [/boot/kernel/kernel]...               
Using DTB provided by EFI at 0x7ef0000.
EFI framebuffer information:
addr, size     0x3e2fe000, 0x7e9000
dimensions     1920 x 1080
stride         1920
masks          0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000
---<<BOOT>>---
panic: Too many early devmap mappings
cpuid = 0
time = 1
KDB: stack backtrace:
. . .

So my configuration files were not needed to have the failure
that I've been getting for the debug kernels.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)