From db49918edb501d8763fcac9244f511c861061bb6 Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@spreadspace.org>
Date: Sat, 6 Jul 2013 23:39:25 +0000
Subject: writing to flash works now

git-svn-id: https://svn.spreadspace.org/pic/trunk@44 a09c6847-51d9-44de-8ef2-e725cf50f3c7
---
 bootloader/bootloader.asm | 73 ++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 57 insertions(+), 16 deletions(-)

(limited to 'bootloader/bootloader.asm')

diff --git a/bootloader/bootloader.asm b/bootloader/bootloader.asm
index 0ea30a7..dc7d119 100644
--- a/bootloader/bootloader.asm
+++ b/bootloader/bootloader.asm
@@ -41,7 +41,7 @@ FSS             EQU       .8
 MESS_H          EQU       .0
 MESS_L          EQU       .64
 SUPPORTED_H     EQU       .0
-SUPPORTED_L     EQU       b'00011111' ; reset, read/write flash, read/write eeprom
+SUPPORTED_L     EQU       b'00011110' ; read/write flash, read/write eeprom
 
   ;; ERROR codes
 E_OK            EQU       .0
@@ -296,17 +296,6 @@ cmd_boot
   call      send_answer
   goto      USERVECT
 
-  ;; ** reset *******
-cmd_reset
-  movlw     E_OK
-  movwf     combuff + .1
-  movlw     .2
-  call      send_answer
-  movlw     b'00000001'
-  movwf     WDTCON		    ; why does this not work?????
-cmd_reset_wait
-  goto      cmd_reset_wait
-
   ;; ** read flash *******
 cmd_r_flash
   call      read_flash_segment
@@ -315,10 +304,7 @@ cmd_r_flash
 
   ;; ** write flash *******
 cmd_w_flash
-  ;; call      write_flash_segment
-  movlw     E_ADDR_INVALID
-  movwf     combuff + .1
-  movlw     .2
+  call      write_flash_segment
   call      send_answer
   goto      wait_new_cmd
 
@@ -349,6 +335,7 @@ cmd_w_eeprom_len
   goto      wait_cmd
 
   ;; ** not implemented commands *******
+cmd_reset
 cmd_r_config
 cmd_w_config
   movlw     E_NOT_IMPL
@@ -359,6 +346,7 @@ cmd_w_config
 
   ;; -------------------------------------
   ;;  actual flash/eeprom functions
+  ;; flash read --------
 read_flash_segment
   movlw     FSS
   movwf     cnt1
@@ -394,6 +382,59 @@ read_flash_segment_next
   clrf      combuff + .1  ; = E_OK
   retlw     .2 + .2*FSS   ; bytes to send
 
+  ;; flash write --------
+write_flash_segment
+  movlw     FSS                 ; initialize EEADR:EEADRH and FSR
+  movwf     cnt1
+  movlw     b'01011000'
+  movwf     STATUS
+  movlw     combuff + .1
+  movwf     FSR
+  movf      INDF,w
+  movwf     EEADR
+  incf      FSR,f
+  movf      INDF,w
+  movwf     EEADRH
+
+write_flash_segment_loop
+  incf      FSR,f               ; load data into EEDAT:EEDATH
+  movf      INDF,w
+  movwf     EEDAT
+  incf      FSR,f
+  movf      INDF,w
+  movwf     EEDATH
+
+  bsf       STATUS,RP0          ; if code word is 0xFFFF, read the current value first
+  btfss     INDF,7              ; this will leave this word unchanged
+  goto      write_flash_segment_write
+
+  bsf       EECON1,EEPGD
+  bsf       EECON1,RD
+  nop
+  nop
+
+write_flash_segment_write
+  bsf       EECON1,EEPGD        ; now start the acutal write sequence
+  bsf       EECON1,WREN
+  movlw     H'55'
+  movwf     EECON2
+  movlw     H'AA'
+  movwf     EECON2
+  bsf       EECON1,WR
+  nop
+  nop
+  bcf       EECON1,WREN
+  bcf       STATUS,RP0
+  incfsz    EEADR,f             ; increment flash address
+  goto      write_flash_segment_next
+  incf      EEADRH,f
+write_flash_segment_next
+  decfsz    cnt1,f
+  goto      write_flash_segment_loop
+  bcf       STATUS,RP1
+  clrf      combuff + .1  ; = E_OK
+  retlw     .2            ; bytes to send
+
   ;; -------------------------------------
   ;; -------------------------------------
   ;; dummy user code
-- 
cgit v1.2.3