Credits:

Defa

How To

Add this routine in free space and note the offset:

push  {lr}
ldr   r0, var
ldr   r3, =0x806E569 @VarGet
bl    linker
ldr   r1, =0x300500C @gSaveBlock2ptr
ldr   r1, [r1]
strb  r0, [r1,#8] @->playerGender
ldr   r1, =0x2037078 @gPlayerAvatar
strb  r0, [r1,#7] @.gender
ldr   r3, =0x81504A9 @QL_GfxTransition_Normal
bl    linker
pop   {pc}
linker: bx r3
var: .word 0x4000

Set temp0 to the gender index you want to set (default: 0 = male/Red, 1 = female/Leaf)

Use callasm offset+1 as usual.

NOTE: If you want to use a different variable, change "4000" at the bottom of the routine

Happy Hacking!