Class DarwinGetArpListHead

source code

One version of arp_init looks like this:

void
arp_init(void)
{
    VERIFY(!arpinit_done);

    LIST_INIT(&llinfo_arp); // <-- This is the global we want.

    llinfo_arp_zone = zinit(sizeof (struct llinfo_arp),
        LLINFO_ARP_ZONE_MAX * sizeof (struct llinfo_arp), 0,
        LLINFO_ARP_ZONE_NAME);
    if (llinfo_arp_zone == NULL)
        panic("%s: failed allocating llinfo_arp_zone", __func__);

    zone_change(llinfo_arp_zone, Z_EXPAND, TRUE);
    zone_change(llinfo_arp_zone, Z_CALLERACCT, FALSE);

    arpinit_done = 1;
}

Disassembled, the first few instructions look like this:
 0x0 55                   PUSH RBP
 0x1 4889e5               MOV RBP, RSP
 0x4 803d65e9400001       CMP BYTE [RIP+0x40e965], 0x1
 0xb 7518                 JNZ 0xff80090a7f95
 0xd 488d3dee802900       LEA RDI, [RIP+0x2980ee]
0x14 488d35f5802900       LEA RSI, [RIP+0x2980f5]
0x1b baf3000000           MOV EDX, 0xf3

# This is a call to kernel!panic (later kernel!assfail):
0x20 e80b6c1400           CALL 0xff80091eeba0

# This is where it starts initializing the linked list:
0x25 48c70548e94000000000 MOV QWORD [RIP+0x40e948], 0x0
     00
0x30 488d0d0e812900       LEA RCX, [RIP+0x29810e]