Running armv7 on aarch64

Hi,

I’ve recently discovered that I can no longer run an armv7 binary on 
my aarch64 FreeBSD machine.

	$ /usr/local/poudriere/jails/pfSense_plus-devel-main_armv7/usr/bin/id
	ELF binary type "9" not known.
	/bin/sh: 
/usr/local/poudriere/jails/pfSense_plus-devel-main_armv7/usr/bin/id: 
Exec format error
	$ file 
/usr/local/poudriere/jails/pfSense_plus-devel-main_armv7/usr/bin/id
	/usr/local/poudriere/jails/pfSense_plus-devel-main_armv7/usr/bin/id: 
ELF 32-bit LSB executable, ARM, EABI5 version 1 (FreeBSD), dynamically 
linked, interpreter /libexec/ld-elf.so.1, FreeBSD-style, for FreeBSD 
14.0 (1400066), stripped
	$ readelf -e 
/usr/local/poudriere/jails/pfSense_plus-devel-main_armv7/usr/bin/id

	File: 
/usr/local/poudriere/jails/pfSense_plus-devel-main_armv7/usr/bin/id
	ELF Header:
	  Magic:   7f 45 4c 46 01 01 01 09 00 00 00 00 00 00 00 00
	  Class:                             ELF32
	  Data:                              2's complement, little endian
	  Version:                           1 (current)
	  OS/ABI:                            FreeBSD
	  ABI Version:                       0
	  Type:                              EXEC (Executable file)
	  Machine:                           ARM
	  Version:                           0x1
	  Entry point address:               0x20ef0
	  Start of program headers:          52 (bytes into file)
	  Start of section headers:          8912 (bytes into file)
	  Flags:                             0x5000400, Version5 EABI, VFP
	  Size of this header:               52 (bytes)
	  Size of program headers:           32 (bytes)
	  Number of program headers:         11
	  Size of section headers:           40 (bytes)
	  Number of section headers:         28
	  Section header string table index: 27

	Elf file type is EXEC (Executable file)
	Entry point 0x20ef0
	There are 11 program headers, starting at offset 52

	Program Headers:
	  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg 
Align
	  PHDR           0x000034 0x00010034 0x00010034 0x00160 0x00160 R   0x4
	  INTERP         0x000194 0x00010194 0x00010194 0x00015 0x00015 R   0x1
	      [Requesting program interpreter: /libexec/ld-elf.so.1]
	  LOAD           0x000000 0x00010000 0x00010000 0x00ccc 0x00ccc R   
0x10000
	  LOAD           0x000ccc 0x00020ccc 0x00020ccc 0x01294 0x01294 R E 
0x10000
	  LOAD           0x001f60 0x00031f60 0x00031f60 0x000c8 0x000c8 RW  
0x10000
	  LOAD           0x002028 0x00042028 0x00042028 0x000a0 0x00138 RW  
0x10000
	  DYNAMIC        0x001f68 0x00031f68 0x00031f68 0x000c0 0x000c0 RW  0x4
	  GNU_RELRO      0x001f60 0x00031f60 0x00031f60 0x000c8 0x000c8 R   0x1
	  GNU_STACK      0x000000 0x00000000 0x00000000 0x00000 0x00000 RW  0
	  NOTE           0x0001ac 0x000101ac 0x000101ac 0x00064 0x00064 R   0x4
	  ARM_EXIDX      0x00090c 0x0001090c 0x0001090c 0x00068 0x00068 R   0x4

	 Section to Segment mapping:
	  Segment Sections...
	   00
	   01     .interp
	   02     .interp .note.tag .dynsym .gnu.version .gnu.version_r 
.gnu.hash .hash .dynstr .rel.dyn .ARM.exidx .rel.plt .rodata .ARM.extab
	   03     .text .init .fini .plt
	   04     .jcr .init_array .dynamic
	   05     .data .got.plt .bss
	   06     .dynamic
	   07     .jcr .init_array .dynamic
	   08
	   09     .note.tag
	   10     .ARM.exidx
	There are 28 section headers, starting at offset 0x22d0:

	Section Headers:
	  [Nr] Name              Type            Addr     Off    Size   ES Flg 
Lk Inf Al
	  [ 0]                   NULL            00000000 000000 000000 00      
0   0  0
	  [ 1] .interp           PROGBITS        00010194 000194 000015 00   A  
0   0  1
	  [ 2] .note.tag         NOTE            000101ac 0001ac 000064 00   A  
0   0  4
	  [ 3] .dynsym           DYNSYM          00010210 000210 0002c0 10   A  
8   1  4
	  [ 4] .gnu.version      SUNW_versym     000104d0 0004d0 000058 02   A  
3   0  2
	  [ 5] .gnu.version_r    SUNW_verneed    00010528 000528 000050 00   A  
8   2  4
	  [ 6] .gnu.hash         GNU_HASH        00010578 000578 000030 00   A  
3   0  4
	  [ 7] .hash             HASH            000105a8 0005a8 000168 04   A  
3   0  4
	  [ 8] .dynstr           STRTAB          00010710 000710 0001e3 00   A  
0   0  1
	  [ 9] .rel.dyn          REL             000108f4 0008f4 000018 08  AI  
3   0  4
	  [10] .ARM.exidx        ARM_EXIDX       0001090c 00090c 000068 00   A 
14   0  4
	  [11] .rel.plt          REL             00010974 000974 000120 08  AI  
3  22  4
	  [12] .rodata           PROGBITS        00010a94 000a94 00021f 01 AMS  
0   0  1
	  [13] .ARM.extab        PROGBITS        00010cb4 000cb4 000018 00   A  
0   0  4
	  [14] .text             PROGBITS        00020ccc 000ccc 000ff0 00  AX  
0   0  4
	  [15] .init             PROGBITS        00021cc0 001cc0 000014 00  AX  
0   0 16
	  [16] .fini             PROGBITS        00021ce0 001ce0 000014 00  AX  
0   0 16
	  [17] .plt              PROGBITS        00021d00 001d00 000260 00  AX  
0   0 16
	  [18] .jcr              PROGBITS        00031f60 001f60 000004 00  WA  
0   0  4
	  [19] .init_array       INIT_ARRAY      00031f64 001f64 000004 00  WA  
0   0  4
	  [20] .dynamic          DYNAMIC         00031f68 001f68 0000c0 08  WA  
8   0  4
	  [21] .data             PROGBITS        00042028 002028 000004 00  WA  
0   0  4
	  [22] .got.plt          PROGBITS        0004202c 00202c 00009c 00  WA  
0   0  4
	  [23] .bss              NOBITS          00042100 0020c8 000060 00  WA  
0   0 64
	  [24] .comment          PROGBITS        00000000 0020c8 0000b6 01  MS  
0   0  1
	  [25] .ARM.attributes   ARM_ATTRIBUTES  00000000 00217e 000049 00      
0   0  1
	  [26] .gnu_debuglink    PROGBITS        00000000 0021c7 000010 00      
0   0  1
	  [27] .shstrtab         STRTAB          00000000 0021d7 0000f7 00      
0   0  1
	Key to Flags:
	  W (write), A (alloc), X (execute), M (merge), S (strings)
	  I (info), L (link order), G (group), x (unknown)
	  O (extra OS processing required) o (OS specific), p (processor 
specific)

It’s not quite clear to me how this is supposed to work (now). On 
amd64 there’s a separate /libexec/ld-elf32.so.1, which we don’t have 
on aarch64. Is it supposed to be built?

It’s broken on ab9293239c7d and e03b7883e97c at the very least.

—
Kristof