From 614a30fd4e683f3765b9d92a4c75badd8775dc0d Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Thu, 1 May 2025 00:55:33 +0200
Subject: [PATCH] avr: generate new uid if the current one consists of 4 equal
 bytes.

---
 avr/common/utils.asm | 32 ++++++++++++--------------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/avr/common/utils.asm b/avr/common/utils.asm
index 81ef3ea..e297b9b 100644
--- a/avr/common/utils.asm
+++ b/avr/common/utils.asm
@@ -397,35 +397,27 @@ Utils_SetupUid:
   in r15, SREG
   cli
     rcall Utils_ReadUid            ; (R16, X)
-    mov r16, r18                   ; all 0x00?
-    or r16, r19
-    or r16, r20
-    or r16, r21
-    breq Utils_SetupUid_generate   ; yep, go generate one
-    mov r16, r18                   ; all 0xff?
-    and r16, r19
-    and r16, r20
-    and r16, r21
-    inc r16
-    breq Utils_SetupUid_generate   ; yep, go generate one
-  out SREG, r15
-  clc
-  ret
-Utils_SetupUid_generate:
-    ldi xl, LOW(EEPROM_OFFS_UUID)
+    cp r18, r19                    ; all the same?
+    brne Utils_SetupUid_uidOkay    ; different, jmp
+    cp r18, r20
+    brne Utils_SetupUid_uidOkay    ; different, jmp
+    cp r18, r21
+    brne Utils_SetupUid_uidOkay    ; different, jmp
+    ldi xl, LOW(EEPROM_OFFS_UUID)  ; all the same, generate new uid
     ldi xh, HIGH(EEPROM_OFFS_UUID)
     rcall Utils_PseudoRandom       ; byte 0 (R16, R17, R18, R19)
     inc r16
-    rcall Utils_WriteEepromIncr        ; (R17)
+    rcall Utils_WriteEepromIncr    ; (R17)
     rcall Utils_PseudoRandom       ; byte 1
-    rcall Utils_WriteEepromIncr
+    rcall Utils_WriteEepromIncr    ; (R17)
     rcall Utils_PseudoRandom       ; byte 2
-    rcall Utils_WriteEepromIncr
+    rcall Utils_WriteEepromIncr    ; (R17)
     rcall Utils_PseudoRandom       ; byte 3
-    rcall Utils_WriteEepromIncr
+    rcall Utils_WriteEepromIncr    ; (R17)
   
     rcall Utils_UpdateSeedInEeprom ; (R16, R17, R18, R19, X)
   
+Utils_SetupUid_uidOkay:
   out SREG, r15
   sec
   ret