This tutorial is awesome. After learning from it, I find a way to re-produce the FS patch.
Follow the Switch-Ghidra-Guides, we can setup the hactool and ghidra.
With hactool, we can find which nca file is for fat32 (with title id
0100000000000819) with one-liner bash:
Bash:
for f in $(ls firmware/); do if hactool --disablekeywarns -t nca firmware/$f | grep -q 0100000000000819; then echo $f; fi; done
Then we get the code file:
Code:
hactool --intype=nca --romfsdir=romfs firmware/2151dbc5cfb38fb3353a15d91456533f.nca
hactool --intype=pk21 --ini1dir=romfs/nx/ini1 romfs/nx/package2
hactool --intype=kip1 --uncompressed=uncompressed_fat32.kip1 romfs/nx/ini1/FS.kip1
Load it in ghidra. First we use
File -> Export Program, to dump the whole decompiled C code to a file.
Then we search for "
0x234c02" in the C code and get the following part.
C:
if ((uVar10 & 1) == 0) {
uVar11 = 0x234c02;
uVar12 = 0x39e9ae0a190b16f2;
}
0x234c02 is for the error code
2002-4518 that means "nca header signature verification failed".
In C code file we find which function this part is in, and open it in ghidra.
Select the "if" line in C function, We will find the corresponding "tbz" instruction.
What we want to do is just "nop" it. That's what sys-patch has done.
(More hints: for the ES patch search for 0x291 (error code 2145-0001), and for the NIFM patch search for "ctest.cdn".)
plus everything else is working soo that would be alot my switch has had done to it id have to configure all over so I don't really wanna do that.
