How arguments are passed to the printf() function? - c

Question

I am trying to understand the assembly code for a simple program, shown below.
void f()
{
int i, x = 0;
for (i = 0; i < 10; i++)
x++;
printf("Value of x: %d\n", x);
}
and its corresponding assembly code on my machine is
00000000000007d4 <f>:
7d4: a9be7bfd stp x29, x30, [sp, #-32]!
7d8: 910003fd mov x29, sp
7dc: b9001fff str wzr, [sp, #28]
7e0: b9001bff str wzr, [sp, #24]
7e4: 14000007 b 800 <f+0x2c>
7e8: b9401fe0 ldr w0, [sp, #28]
7ec: 11000400 add w0, w0, #0x1
7f0: b9001fe0 str w0, [sp, #28]
7f4: b9401be0 ldr w0, [sp, #24]
7f8: 11000400 add w0, w0, #0x1
7fc: b9001be0 str w0, [sp, #24]
800: b9401be0 ldr w0, [sp, #24]
804: 7100241f cmp w0, #0x9
808: 54ffff0d b.le 7e8 <f+0x14>
80c: b9401fe1 ldr w1, [sp, #28]
810: 90000000 adrp x0, 0 <__abi_tag-0x278>
814: 9121c000 add x0, x0, #0x870
818: 97ffff9a bl 680 <printf#plt>
81c: d503201f nop
820: a8c27bfd ldp x29, x30, [sp], #32
824: d65f03c0 ret
I understand the loop, but line 814 - 818 is really confusion to me. What's the purpose of adding #0x870 to x0? What does line 818 mean? And how arguments are passed to the printf() function?
I expect words like "Value of x: " appears in the assembly code, but it seems like the compiler simply knows what to print.