Kernels compiled on evbarm/aarch64 are 100MB bigger than kernels compiled on x86-64

[Jason Mitchell <jmitchel%bigjar.com@localhost>]

Hello,

I noticed this a while back, but didn’t have the time to track it down. 
As the subject says, kernels compiled on aarch64 machines (using either 
build.sh or config/make depend/make) are roughly 100Mb bigger than 
kernels compiled on x86-64 machines (both on NetBSD and MacOS). I tested 
this with a custom kernel config file and also the evbarm GENERIC64 
kernel config.

The strange thing is that the kernel size looks fine when reported by 
the compiler (this kernel has an 100Mb ramdisk):

NetBSD box:

NetBSD 9.3 (ARMNUK) #0: Wed Aug 30 15:16:30 UTC 2023
   text    data     bss     dec     hex filename
8276380 105652143       1534088 115462611       6e1d1d3 netbsd

<snip>

NetBSD_machine# ls -al netbsd
-rwxr-xr-x  1 root  wsrc  219535264 Aug 30 15:33 netbsd


Here’s the same kernel compiled on MacOS:

MacOS_machine:src jmitchel$ cd sys/arch/evbarm/compile/obj/ARMNUK/
MacOS_machine:ARMNUK jmitchel$ ls -al netbsd
-rwxr-xr-x  1 jmitchel  staff  117846720 Aug 30 13:27 netbsd

Back to the NetBSD evbarm box. Here’s the GENERIC64 kernel:


NetBSD_machine:/usr/src/NetBSD9.3/sys/arch/evbarm/compile/obj/GENERIC64# 
ls -al netbsd
-rwxr-xr-x  1 root  wheel  112193776 Aug 30 18:46 netbsd

Anyway, I’m happy to help troubleshoot this further, please just let me 
know what I can do.

Thanks,

Jason M.