Created attachment 200341 [details] patch see attached patch
Can you show error log? Also, changes should be submitted upstream first. Without upstreaming aarch64 support will degrade over time. If unlucky this can happen as soon as the next Firefox release. I can't submit to Skia upstream on your behalf due to lack of Google Account and can't help with libc crate due to lack of aarch64 hardware (bug 221185).
I didn't save the log, from memory, the problem with skia is the missing getauxval implementation on FreeBSD/aarch64 and the problem with rust/libc is that 'char' is unsigned on aarch64 (https://svnweb.freebsd.org/ports/head/lang/rust/files/patch-src_liblibc_src_unix_bsd_freebsdlike_freebsd_aarch64.rs?revision=474978&view=markup)
huh, I recently fixed the unsigned char in libstd https://github.com/rust-lang/rust/pull/56640 — surprisingly haven't noticed that in libc, probably due to not testing enough libc-using crates… The patches look good, though I'm not sure about 'In FreeBSD 11 and later, ss_sp is actually a void*' becoming 'if (aarch64) void* else char*'. Does this not matter on amd64 somehow?
A commit references this bug: Author: jbeich Date: Fri Mar 1 19:14:40 UTC 2019 New revision: 494312 URL: https://svnweb.freebsd.org/changeset/ports/494312 Log: www/firefox: unbreak on aarch64 and powerpc64 PR: 234253 Submitted by: Mika?l Urankar Changes: head/mail/thunderbird/files/patch-bug1530098 head/mail/thunderbird/files/patch-gfx_skia_skia_src_core_SkCpu.cpp head/www/cliqz/files/patch-bug1530098 head/www/cliqz/files/patch-mozilla-release_gfx_skia_skia_src_core_SkCpu.cpp head/www/firefox/files/patch-bug1530098 head/www/firefox/files/patch-gfx_skia_skia_src_core_SkCpu.cpp head/www/firefox-esr/files/patch-bug1530098 head/www/firefox-esr/files/patch-gfx_skia_skia_src_core_SkCpu.cpp