Just for fun, I wondered how small a canonical hello world program could be in macOS running an ARM processor. Below is based on what I found here[0] with minor command-line switch alterations to account for a newer OS version.

ARM64 assembly program (hw.s):

  //
  // Assembler program to print "Hello World!"
  // to stdout.
  //
  // X0-X2 - parameters to linux function services
  // X16 - linux function number
  //
  .global _start             // Provide program starting address to linker
  .align 2

  // Setup the parameters to print hello world
  // and then call Linux to do it.

  _start: mov X0, #1     // 1 = StdOut
          adr X1, helloworld // string to print
          mov X2, #13     // length of our string
          mov X16, #4     // MacOS write system call
          svc 0     // Call linux to output the string

  // Setup the parameters to exit the program
  // and then call Linux to do it.

          mov     X0, #0      // Use 0 return code
          mov     X16, #1     // Service command code 1 terminates this program
          svc     0           // Call MacOS to terminate the program

  helloworld:      .ascii  "Hello World!\n"

Assembling and linking commands:

  as -o hw.o hw.s &&
  ld -macos_version_min 14.0.0 -o hw hw.o -lSystem -syslibroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.2.sdk -e _start -arch arm64

Resulting file sizes:

  -rwxr-xr-x  1 <uid>  <gid>    16K Jun 18 21:23 hw
  -rw-r--r--  1 <uid>  <gid>   440B Jun 18 21:23 hw.o
  -rw-r--r--  1 <uid>  <gid>   862B Jun 18 21:21 hw.s

0 - https://smist08.wordpress.com/2021/01/08/apple-m1-assembly-l...