Merge branch 'osccal' of https://github.com/matthijskooijman/optiboot …

…into tinytuner

This was submitted as a pull request to optiboot's main repository

  * Optiboot#183

See here for why I'm merging it

  * SpenceKonde/ATTinyCore#141 (comment)

untested yet.

Conflicts:
	optiboot/bootloaders/optiboot/Makefile

optiboot/bootloaders/optiboot/Makefile

@@ -60,7 +60,7 @@ export
 # defaults
 # Set this explicitly in your make rules!
 # MCU_TARGET = atmega168
-LDSECTIONS  = -Wl,--section-start=.text=0x3e00 -Wl,--section-start=.version=0x3ffe
+LDSECTIONS  = -Wl,--section-start=.text=0x3e00 -Wl,--section-start=.osccal=0x3ffd -Wl,--section-start=.version=0x3ffe
 
 # Build environments
 # Start of some ugly makefile-isms to allow optiboot to be built
@@ -198,8 +198,19 @@ ifdef SINGLESPEED
 SS_CMD = -DSINGLESPEED=1
 endif
 
+ifdef OSCCAL_EEPROM_ADDR
+OSCCAL_CMD = -DOSCCAL_EEPROM_ADDR=$(OSCCAL_EEPROM_ADDR)
+dummy = FORCE
+endif
+
+ifdef OSCCAL_PROGMEM
+OSCCAL_CMD = -DOSCCAL_PROGMEM
+dummy = FORCE
+endif
+
 COMMON_OPTIONS = $(BAUD_RATE_CMD) $(LED_START_FLASHES_CMD) $(BIGBOOT_CMD)
 COMMON_OPTIONS += $(SOFT_UART_CMD) $(LED_DATA_FLASH_CMD) $(LED_CMD) $(SS_CMD)
+COMMON_OPTIONS += $(OSCCAL_CMD)
 
 #UART is handled separately and only passed for devices with more than one.
 ifdef UART
@@ -248,7 +259,7 @@ virboot8: TARGET = atmega8
 virboot8: MCU_TARGET = atmega8
 virboot8: CFLAGS += $(COMMON_OPTIONS) '-DVIRTUAL_BOOT_PARTITION' '-Dsave_vect_num=EE_RDY_vect_num'
 virboot8: AVR_FREQ ?= 16000000L 
-virboot8: LDSECTIONS  = -Wl,--section-start=.text=0x1c00 -Wl,--section-start=.version=0x1ffe
+virboot8: LDSECTIONS  = -Wl,--section-start=.text=0x1c00 -Wl,--section-start=.osccal=0x1ffd -Wl,--section-start=.version=0x1ffe
 virboot8: $(PROGRAM)_virboot8.hex
 virboot8: $(PROGRAM)_virboot8.lst
 
@@ -257,7 +268,7 @@ virboot328: TARGET = atmega328
 virboot328: MCU_TARGET = atmega328p
 virboot328: CFLAGS += $(COMMON_OPTIONS) '-DVIRTUAL_BOOT_PARTITION'
 virboot328: AVR_FREQ ?= 16000000L
-virboot328: LDSECTIONS  = -Wl,--section-start=.text=0x7d80 -Wl,--section-start=.version=0x7ffe
+virboot328: LDSECTIONS  = -Wl,--section-start=.text=0x7d80 -Wl,--section-start=.osccal=0x7ffd -Wl,--section-start=.version=0x7ffe
 virboot328: $(PROGRAM)_virboot328.hex
 virboot328: $(PROGRAM)_virboot328.lst
 
@@ -272,7 +283,6 @@ virboot328_isp: LFUSE ?= FF
 virboot328_isp: EFUSE ?= 05
 virboot328_isp: isp
 
-
 #---------------------------------------------------------------------------
 # "Board-level Platform" targets.
 # A "Board-level Platform" implies a manufactured platform with a particular
@@ -474,10 +484,10 @@ clean:
 	$(OBJDUMP) -h -S $< > $@
 
 %.hex: %.elf
-	$(OBJCOPY) -j .text -j .data -j .version --set-section-flags .version=alloc,load -O ihex $< $@
+	$(OBJCOPY) -j .text -j .data -j .version -j .osccal --set-section-flags .version=alloc,load --set-section-flags .osccal=alloc,load -O ihex $< $@
 
 %.srec: %.elf
-	$(OBJCOPY) -j .text -j .data -j .version --set-section-flags .version=alloc,load -O srec $< $@
+	$(OBJCOPY) -j .text -j .data -j .version -j .osccal -set-section-flags .version=alloc,load --set-section-flags .osccal=alloc,load -O srec $< $@
 
 %.bin: %.elf
-	$(OBJCOPY) -j .text -j .data -j .version --set-section-flags .version=alloc,load -O binary $< $@
+	$(OBJCOPY) -j .text -j .data -j .version -j .osccal --set-section-flags .version=alloc,load --set-section-flags .osccal=alloc,load -O binary $< $@

optiboot/bootloaders/optiboot/optiboot.c

@@ -128,6 +128,18 @@
 /* UART number (0..n) for devices with more than          */
 /* one hardware uart (644P, 1284P, etc)                   */
 /*                                                        */
+/* OSCCAL_EEPROM_ADDR                                     */
+/* On startup, load an oscillator calibration value from  */
+/* this address in EEPROM and write it to OSCCAL (unless  */
+/* it is 0xff).                                           */
+/*                                                        */
+/* OSCCAL_PROGMEM                                         */
+/* On startup, load an oscillator calibration value from  */
+/* the top of the flash memory (unless it is 0xff, which  */
+/* is the default). This byte is put into its own .osccal */
+/* section, so its address should be set through the      */
+/* linker.                                                */
+/*                                                        */
 /**********************************************************/
 
 /**********************************************************/
@@ -239,6 +251,11 @@
 unsigned const int __attribute__((section(".version"))) 
 optiboot_version = 256*(OPTIBOOT_MAJVER + OPTIBOOT_CUSTOMVER) + OPTIBOOT_MINVER;
 
+#if defined(OSCCAL_PROGMEM)
+unsigned const char __attribute__((section(".osccal")))
+optiboot_osccal = 0xff;
+#endif
+
 
 #include <inttypes.h>
 #include <avr/io.h>
@@ -519,6 +536,19 @@ int main(void) {
   SP=RAMEND;  // This is done by hardware reset
 #endif
 
+#if defined(OSCCAL_EEPROM_ADDR)
+  // Load OSCCAL before app start, so the app does not have to
+  ch = eeprom_read_byte((uint8_t*)OSCCAL_EEPROM_ADDR);
+  if (ch != 0xff)
+    OSCCAL = ch;
+#endif
+
+#if defined(OSCCAL_PROGMEM)
+  // Load OSCCAL before app start, so the app does not have to
+  ch = pgm_read_byte(&optiboot_osccal);
+  if (ch != 0xff)
+    OSCCAL = ch;
+#endif
   /*
    * modified Adaboot no-wait mod.
    * Pass the reset reason to app.  Also, it appears that an Uno poweron