avr: reorganized common code.

2026-04-20 23:56:52 +02:00
parent 2d2105ae00
commit abe218e7b0
12 changed files with 281 additions and 155 deletions
--- a/avr/common/devuid.asm
+++ b/avr/common/devuid.asm
@@ -0,0 +1,112 @@
+; ***************************************************************************
+; copyright   : (C) 2026 by Martin Preuss
+; email       : martin@libchipcard.de
+;
+; ***************************************************************************
+; * This file is part of the project "AqHome".                              *
+; * Please see toplevel file COPYING of that project for license details.   *
+; ***************************************************************************
+
+#ifndef AQH_AVR_COMMON_DEVUID_ASM
+#define AQH_AVR_COMMON_DEVUID_ASM
+
+
+
+; ***************************************************************************
+; code
+
+
+.cseg
+
+
+
+; ---------------------------------------------------------------------------
+; @routine DevUid_Read
+
+; Read UID from EEPROM.
+;
+; @return r21:r20:r19:r18 UID
+; @clobbers R16, X
+
+DevUid_ReadFromEeprom:
+  ldi xl, LOW(EEPROM_OFFS_UUID)
+  ldi xh, HIGH(EEPROM_OFFS_UUID)
+  rcall Eeprom_ReadByte          ; r16=byte read (none)
+  brcc DevUid_ReadFromEeprom_ret
+  mov r18, r16
+  adiw xh:xl, 1
+
+  rcall Eeprom_ReadByte          ; r16=byte read (none)
+  brcc DevUid_ReadFromEeprom_ret
+  mov r19, r16
+  adiw xh:xl, 1
+
+  rcall Eeprom_ReadByte          ; r16=byte read (none)
+  brcc DevUid_ReadFromEeprom_ret
+  mov r20, r16
+  adiw xh:xl, 1
+
+  rcall Eeprom_ReadByte          ; r16=byte read (none)
+  brcc DevUid_ReadFromEeprom_ret
+  mov r21, r16
+
+DevUid_ReadFromEeprom_ret:
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine DevUid_Setup @global
+;
+; Reads UID from EEPROM. If not set generate a new one and store it in EEPROM.
+;
+; @return CFLAG set if new generated, cleared if there already was one.
+; @clobbers R16, R18, R19, R20, R21, X (R17)
+
+DevUid_Setup:
+    rcall DevUid_ReadFromEeprom        ; (R16, X)
+    cp r18, r19                     ; all the same?
+    brne DevUid_Setup_uidOkay     ; different, jmp
+    cp r18, r20
+    brne DevUid_Setup_uidOkay     ; different, jmp
+    cp r18, r21
+    brne DevUid_Setup_uidOkay     ; different, jmp
+
+    ldi xl, LOW(EEPROM_OFFS_UUID)   ; all the same, generate new uid
+    ldi xh, HIGH(EEPROM_OFFS_UUID)
+    rcall RAND_PseudoRandom         ; byte 0 (R16, R17, R18, R19)
+    inc r16
+    rcall Eeprom_WriteByteIfChanged ; (r17)
+    brcc DevUid_Setup_ret
+    adiw xh:xl, 1
+
+    rcall RAND_PseudoRandom         ; byte 1
+    rcall Eeprom_WriteByteIfChanged ; (r17)
+    brcc DevUid_Setup_ret
+    adiw xh:xl, 1
+
+    rcall RAND_PseudoRandom         ; byte 2
+    rcall Eeprom_WriteByteIfChanged ; (r17)
+    brcc DevUid_Setup_ret
+    adiw xh:xl, 1
+
+    rcall RAND_PseudoRandom         ; byte 3
+    rcall Eeprom_WriteByteIfChanged ; (r17)
+    brcc DevUid_Setup_ret
+  
+    rcall RAND_UpdateSeedInEeprom ; (R16, R17, R18, R19, X)
+  
+DevUid_Setup_uidOkay:
+  sec
+DevUid_Setup_ret:
+  ret
+; @end
+
+
+
+
+
+
+#endif
+