SMS-GCI-Loader/gecko/code/gecko-gosub.s

## check status
### r3 = GCTDST
  lis r3, GCTDST@ha
  lwzu r0, GCTDST@l(r3)
### return if not DONE(2)
  cmpwi r0, 2
  bnelr

## backup r15 (pointer to current gecko instruction)
  add r0, r15, r4
  stw r0, 4(r3)
## update r15 = dst + 8(GCTDST.code-r3) - r4(this C0 code size)
  addi r15, r3, 8
  sub r15, r15, r4
  blr
Add script to build gecko code of GCI Loader - GCI Loader: gecko-gosub + 06 bin + 04 bl to onReadOptionBlock - place GCI Loader code at 817FE800 since [817FEEA0, 81800000) is used by system - place buffer at 817F1800 (instead of 817F1000+4) since there seems to be some alignment issue - Assume file size == 0x2000*6 since fileInfo->length seems to be 0 2023-02-10 23:20:40 +09:00			`## check status`
			`### r3 = GCTDST`
			`lis r3, GCTDST@ha`
			`lwzu r0, GCTDST@l(r3)`
			`### return if not DONE(2)`
			`cmpwi r0, 2`
			`bnelr`

			`## backup r15 (pointer to current gecko instruction)`
			`add r0, r15, r4`
			`stw r0, 4(r3)`
			`## update r15 = dst + 8(GCTDST.code-r3) - r4(this C0 code size)`
			`addi r15, r3, 8`
			`sub r15, r15, r4`
			`blr`