FIRM installs: clarify sighax injection

Fixes d0k3#397

README.md

@@ -136,7 +136,7 @@ With the possibilites GodMode9 provides, not everything may be obvious at first
 * __Transfer CTRNAND images between systems__: Transfer the file located at `S:/ctrnand_full.bin` (or `E:`/ `I:`). On the receiving system, press A, select `CTRNAND Options...`, then `Transfer to NAND`.
 * __Embed an essential backup right into a NAND dump__: This is available in the A button menu for NAND dumps. Essential backups contain NAND header, `movable.sed`, `LocalFriendCodeSeed_B`, `SecureInfo_A`, NAND CID and OTP. If your local SysNAND does not contain an embedded backup, you will be asked to do one at startup. To update the essential SysNAND backup at a later point in time, press A on `S:/nand.bin` and select `NAND image options...` -> `Update embedded backup`.
 * __Install an AES key database to your NAND__: For `aeskeydb.bin` files the option is found in `aeskeydb.bin options` -> `Install aeskeydb.bin`. Only the recommended key database can be installed (see above). With an installed key database, it is possible to run the GodMode9 bootloader completely from NAND.
-* __Install FIRM files to your NAND__: Found inside the A button menu for FIRM files, select `FIRM options` -> `Install FIRM`. __Use this with caution__ - installing an incompatible FIRM file will lead to a __brick__.
+* __Install FIRM files to your NAND__: Found inside the A button menu for FIRM files, select `FIRM options` -> `Install FIRM`. __Use this with caution__ - installing an incompatible FIRM file will lead to a __brick__. The FIRMs signature will automagically be replaced with a sighax signature to ensure compatibility.
 * __Actually use that extra NAND space__: You can setup a __bonus drive__ via the HOME menu, which will be available via drive letter `8:`. (Only available on systems that have the extra space.)
 * __Fix certain problems on your NANDs__: You can fix CMACs for a whole drive (works on `A:`, `B:`, `S:` and `E:`) via an entry in the R+A button menu, or even restore borked NAND headers back to a functional state (inside the A button menu of borked NANDs and available for `S:/nand_hdr.bin`). Recommended only for advanced users!
 

arm9/source/utils/nandutil.c

@@ -550,7 +550,7 @@ u32 SafeInstallFirmBuffered(const char* path, u32 slots, u8* buffer, u32 bufsiz)
     }
 
     // all checked, ready to go
-    if (!ShowUnlockSequence(6, "!WARNING!\n \nProceeding will install the\nprovided FIRM to the SysNAND.\n \nInstalling an unsupported FIRM\nwill BRICK your console!")) return 1;
+    if (!ShowUnlockSequence(6, "!WARNING!\n \nProceeding will install the\nprovided FIRM to the SysNAND\nand inject sighax.\n \nInstalling an unsupported FIRM\nwill BRICK your console!")) return 1;
     // if (!SetWritePermissions(PERM_SYS_LVL3, true)) return 1; // one unlock sequence is enough
 
     // point of no return