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No commits in common. "master" and "v2.0" have entirely different histories.
1
.gitignore
vendored
1
.gitignore
vendored
@ -3,5 +3,4 @@
|
|||||||
*.bin
|
*.bin
|
||||||
*.hex
|
*.hex
|
||||||
*.lst
|
*.lst
|
||||||
*.lss
|
|
||||||
*.map
|
*.map
|
||||||
|
262
LICENSE
262
LICENSE
@ -1,262 +0,0 @@
|
|||||||
GNU GENERAL PUBLIC LICENSE
|
|
||||||
|
|
||||||
Version 2, June 1991
|
|
||||||
|
|
||||||
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
|
|
||||||
|
|
||||||
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
|
|
||||||
|
|
||||||
Everyone is permitted to copy and distribute verbatim copies of this license
|
|
||||||
document, but changing it is not allowed.
|
|
||||||
|
|
||||||
Preamble
|
|
||||||
|
|
||||||
The licenses for most software are designed to take away your freedom to share
|
|
||||||
and change it. By contrast, the GNU General Public License is intended to
|
|
||||||
guarantee your freedom to share and change free software--to make sure the
|
|
||||||
software is free for all its users. This General Public License applies to
|
|
||||||
most of the Free Software Foundation's software and to any other program whose
|
|
||||||
authors commit to using it. (Some other Free Software Foundation software
|
|
||||||
is covered by the GNU Lesser General Public License instead.) You can apply
|
|
||||||
it to your programs, too.
|
|
||||||
|
|
||||||
When we speak of free software, we are referring to freedom, not price. Our
|
|
||||||
General Public Licenses are designed to make sure that you have the freedom
|
|
||||||
to distribute copies of free software (and charge for this service if you
|
|
||||||
wish), that you receive source code or can get it if you want it, that you
|
|
||||||
can change the software or use pieces of it in new free programs; and that
|
|
||||||
you know you can do these things.
|
|
||||||
|
|
||||||
To protect your rights, we need to make restrictions that forbid anyone to
|
|
||||||
deny you these rights or to ask you to surrender the rights. These restrictions
|
|
||||||
translate to certain responsibilities for you if you distribute copies of
|
|
||||||
the software, or if you modify it.
|
|
||||||
|
|
||||||
For example, if you distribute copies of such a program, whether gratis or
|
|
||||||
for a fee, you must give the recipients all the rights that you have. You
|
|
||||||
must make sure that they, too, receive or can get the source code. And you
|
|
||||||
must show them these terms so they know their rights.
|
|
||||||
|
|
||||||
We protect your rights with two steps: (1) copyright the software, and (2)
|
|
||||||
offer you this license which gives you legal permission to copy, distribute
|
|
||||||
and/or modify the software.
|
|
||||||
|
|
||||||
Also, for each author's protection and ours, we want to make certain that
|
|
||||||
everyone understands that there is no warranty for this free software. If
|
|
||||||
the software is modified by someone else and passed on, we want its recipients
|
|
||||||
to know that what they have is not the original, so that any problems introduced
|
|
||||||
by others will not reflect on the original authors' reputations.
|
|
||||||
|
|
||||||
Finally, any free program is threatened constantly by software patents. We
|
|
||||||
wish to avoid the danger that redistributors of a free program will individually
|
|
||||||
obtain patent licenses, in effect making the program proprietary. To prevent
|
|
||||||
this, we have made it clear that any patent must be licensed for everyone's
|
|
||||||
free use or not licensed at all.
|
|
||||||
|
|
||||||
The precise terms and conditions for copying, distribution and modification
|
|
||||||
follow.
|
|
||||||
|
|
||||||
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
|
|
||||||
|
|
||||||
0. This License applies to any program or other work which contains a notice
|
|
||||||
placed by the copyright holder saying it may be distributed under the terms
|
|
||||||
of this General Public License. The "Program", below, refers to any such program
|
|
||||||
or work, and a "work based on the Program" means either the Program or any
|
|
||||||
derivative work under copyright law: that is to say, a work containing the
|
|
||||||
Program or a portion of it, either verbatim or with modifications and/or translated
|
|
||||||
into another language. (Hereinafter, translation is included without limitation
|
|
||||||
in the term "modification".) Each licensee is addressed as "you".
|
|
||||||
|
|
||||||
Activities other than copying, distribution and modification are not covered
|
|
||||||
by this License; they are outside its scope. The act of running the Program
|
|
||||||
is not restricted, and the output from the Program is covered only if its
|
|
||||||
contents constitute a work based on the Program (independent of having been
|
|
||||||
made by running the Program). Whether that is true depends on what the Program
|
|
||||||
does.
|
|
||||||
|
|
||||||
1. You may copy and distribute verbatim copies of the Program's source code
|
|
||||||
as you receive it, in any medium, provided that you conspicuously and appropriately
|
|
||||||
publish on each copy an appropriate copyright notice and disclaimer of warranty;
|
|
||||||
keep intact all the notices that refer to this License and to the absence
|
|
||||||
of any warranty; and give any other recipients of the Program a copy of this
|
|
||||||
License along with the Program.
|
|
||||||
|
|
||||||
You may charge a fee for the physical act of transferring a copy, and you
|
|
||||||
may at your option offer warranty protection in exchange for a fee.
|
|
||||||
|
|
||||||
2. You may modify your copy or copies of the Program or any portion of it,
|
|
||||||
thus forming a work based on the Program, and copy and distribute such modifications
|
|
||||||
or work under the terms of Section 1 above, provided that you also meet all
|
|
||||||
of these conditions:
|
|
||||||
|
|
||||||
a) You must cause the modified files to carry prominent notices stating that
|
|
||||||
you changed the files and the date of any change.
|
|
||||||
|
|
||||||
b) You must cause any work that you distribute or publish, that in whole or
|
|
||||||
in part contains or is derived from the Program or any part thereof, to be
|
|
||||||
licensed as a whole at no charge to all third parties under the terms of this
|
|
||||||
License.
|
|
||||||
|
|
||||||
c) If the modified program normally reads commands interactively when run,
|
|
||||||
you must cause it, when started running for such interactive use in the most
|
|
||||||
ordinary way, to print or display an announcement including an appropriate
|
|
||||||
copyright notice and a notice that there is no warranty (or else, saying that
|
|
||||||
you provide a warranty) and that users may redistribute the program under
|
|
||||||
these conditions, and telling the user how to view a copy of this License.
|
|
||||||
(Exception: if the Program itself is interactive but does not normally print
|
|
||||||
such an announcement, your work based on the Program is not required to print
|
|
||||||
an announcement.)
|
|
||||||
|
|
||||||
These requirements apply to the modified work as a whole. If identifiable
|
|
||||||
sections of that work are not derived from the Program, and can be reasonably
|
|
||||||
considered independent and separate works in themselves, then this License,
|
|
||||||
and its terms, do not apply to those sections when you distribute them as
|
|
||||||
separate works. But when you distribute the same sections as part of a whole
|
|
||||||
which is a work based on the Program, the distribution of the whole must be
|
|
||||||
on the terms of this License, whose permissions for other licensees extend
|
|
||||||
to the entire whole, and thus to each and every part regardless of who wrote
|
|
||||||
it.
|
|
||||||
|
|
||||||
Thus, it is not the intent of this section to claim rights or contest your
|
|
||||||
rights to work written entirely by you; rather, the intent is to exercise
|
|
||||||
the right to control the distribution of derivative or collective works based
|
|
||||||
on the Program.
|
|
||||||
|
|
||||||
In addition, mere aggregation of another work not based on the Program with
|
|
||||||
the Program (or with a work based on the Program) on a volume of a storage
|
|
||||||
or distribution medium does not bring the other work under the scope of this
|
|
||||||
License.
|
|
||||||
|
|
||||||
3. You may copy and distribute the Program (or a work based on it, under Section
|
|
||||||
2) in object code or executable form under the terms of Sections 1 and 2 above
|
|
||||||
provided that you also do one of the following:
|
|
||||||
|
|
||||||
a) Accompany it with the complete corresponding machine-readable source code,
|
|
||||||
which must be distributed under the terms of Sections 1 and 2 above on a medium
|
|
||||||
customarily used for software interchange; or,
|
|
||||||
|
|
||||||
b) Accompany it with a written offer, valid for at least three years, to give
|
|
||||||
any third party, for a charge no more than your cost of physically performing
|
|
||||||
source distribution, a complete machine-readable copy of the corresponding
|
|
||||||
source code, to be distributed under the terms of Sections 1 and 2 above on
|
|
||||||
a medium customarily used for software interchange; or,
|
|
||||||
|
|
||||||
c) Accompany it with the information you received as to the offer to distribute
|
|
||||||
corresponding source code. (This alternative is allowed only for noncommercial
|
|
||||||
distribution and only if you received the program in object code or executable
|
|
||||||
form with such an offer, in accord with Subsection b above.)
|
|
||||||
|
|
||||||
The source code for a work means the preferred form of the work for making
|
|
||||||
modifications to it. For an executable work, complete source code means all
|
|
||||||
the source code for all modules it contains, plus any associated interface
|
|
||||||
definition files, plus the scripts used to control compilation and installation
|
|
||||||
of the executable. However, as a special exception, the source code distributed
|
|
||||||
need not include anything that is normally distributed (in either source or
|
|
||||||
binary form) with the major components (compiler, kernel, and so on) of the
|
|
||||||
operating system on which the executable runs, unless that component itself
|
|
||||||
accompanies the executable.
|
|
||||||
|
|
||||||
If distribution of executable or object code is made by offering access to
|
|
||||||
copy from a designated place, then offering equivalent access to copy the
|
|
||||||
source code from the same place counts as distribution of the source code,
|
|
||||||
even though third parties are not compelled to copy the source along with
|
|
||||||
the object code.
|
|
||||||
|
|
||||||
4. You may not copy, modify, sublicense, or distribute the Program except
|
|
||||||
as expressly provided under this License. Any attempt otherwise to copy, modify,
|
|
||||||
sublicense or distribute the Program is void, and will automatically terminate
|
|
||||||
your rights under this License. However, parties who have received copies,
|
|
||||||
or rights, from you under this License will not have their licenses terminated
|
|
||||||
so long as such parties remain in full compliance.
|
|
||||||
|
|
||||||
5. You are not required to accept this License, since you have not signed
|
|
||||||
it. However, nothing else grants you permission to modify or distribute the
|
|
||||||
Program or its derivative works. These actions are prohibited by law if you
|
|
||||||
do not accept this License. Therefore, by modifying or distributing the Program
|
|
||||||
(or any work based on the Program), you indicate your acceptance of this License
|
|
||||||
to do so, and all its terms and conditions for copying, distributing or modifying
|
|
||||||
the Program or works based on it.
|
|
||||||
|
|
||||||
6. Each time you redistribute the Program (or any work based on the Program),
|
|
||||||
the recipient automatically receives a license from the original licensor
|
|
||||||
to copy, distribute or modify the Program subject to these terms and conditions.
|
|
||||||
You may not impose any further restrictions on the recipients' exercise of
|
|
||||||
the rights granted herein. You are not responsible for enforcing compliance
|
|
||||||
by third parties to this License.
|
|
||||||
|
|
||||||
7. If, as a consequence of a court judgment or allegation of patent infringement
|
|
||||||
or for any other reason (not limited to patent issues), conditions are imposed
|
|
||||||
on you (whether by court order, agreement or otherwise) that contradict the
|
|
||||||
conditions of this License, they do not excuse you from the conditions of
|
|
||||||
this License. If you cannot distribute so as to satisfy simultaneously your
|
|
||||||
obligations under this License and any other pertinent obligations, then as
|
|
||||||
a consequence you may not distribute the Program at all. For example, if a
|
|
||||||
patent license would not permit royalty-free redistribution of the Program
|
|
||||||
by all those who receive copies directly or indirectly through you, then the
|
|
||||||
only way you could satisfy both it and this License would be to refrain entirely
|
|
||||||
from distribution of the Program.
|
|
||||||
|
|
||||||
If any portion of this section is held invalid or unenforceable under any
|
|
||||||
particular circumstance, the balance of the section is intended to apply and
|
|
||||||
the section as a whole is intended to apply in other circumstances.
|
|
||||||
|
|
||||||
It is not the purpose of this section to induce you to infringe any patents
|
|
||||||
or other property right claims or to contest validity of any such claims;
|
|
||||||
this section has the sole purpose of protecting the integrity of the free
|
|
||||||
software distribution system, which is implemented by public license practices.
|
|
||||||
Many people have made generous contributions to the wide range of software
|
|
||||||
distributed through that system in reliance on consistent application of that
|
|
||||||
system; it is up to the author/donor to decide if he or she is willing to
|
|
||||||
distribute software through any other system and a licensee cannot impose
|
|
||||||
that choice.
|
|
||||||
|
|
||||||
This section is intended to make thoroughly clear what is believed to be a
|
|
||||||
consequence of the rest of this License.
|
|
||||||
|
|
||||||
8. If the distribution and/or use of the Program is restricted in certain
|
|
||||||
countries either by patents or by copyrighted interfaces, the original copyright
|
|
||||||
holder who places the Program under this License may add an explicit geographical
|
|
||||||
distribution limitation excluding those countries, so that distribution is
|
|
||||||
permitted only in or among countries not thus excluded. In such case, this
|
|
||||||
License incorporates the limitation as if written in the body of this License.
|
|
||||||
|
|
||||||
9. The Free Software Foundation may publish revised and/or new versions of
|
|
||||||
the General Public License from time to time. Such new versions will be similar
|
|
||||||
in spirit to the present version, but may differ in detail to address new
|
|
||||||
problems or concerns.
|
|
||||||
|
|
||||||
Each version is given a distinguishing version number. If the Program specifies
|
|
||||||
a version number of this License which applies to it and "any later version",
|
|
||||||
you have the option of following the terms and conditions either of that version
|
|
||||||
or of any later version published by the Free Software Foundation. If the
|
|
||||||
Program does not specify a version number of this License, you may choose
|
|
||||||
any version ever published by the Free Software Foundation.
|
|
||||||
|
|
||||||
10. If you wish to incorporate parts of the Program into other free programs
|
|
||||||
whose distribution conditions are different, write to the author to ask for
|
|
||||||
permission. For software which is copyrighted by the Free Software Foundation,
|
|
||||||
write to the Free Software Foundation; we sometimes make exceptions for this.
|
|
||||||
Our decision will be guided by the two goals of preserving the free status
|
|
||||||
of all derivatives of our free software and of promoting the sharing and reuse
|
|
||||||
of software generally.
|
|
||||||
|
|
||||||
NO WARRANTY
|
|
||||||
|
|
||||||
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR
|
|
||||||
THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE
|
|
||||||
STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM
|
|
||||||
"AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
|
|
||||||
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
||||||
FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
|
|
||||||
OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
|
|
||||||
THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
|
|
||||||
|
|
||||||
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
|
|
||||||
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE
|
|
||||||
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
|
|
||||||
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE
|
|
||||||
OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA
|
|
||||||
OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES
|
|
||||||
OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH
|
|
||||||
HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
|
|
||||||
END OF TERMS AND CONDITIONS
|
|
130
Makefile
130
Makefile
@ -1,103 +1,47 @@
|
|||||||
CC := avr-gcc
|
PRG = twiboot
|
||||||
LD := avr-ld
|
OBJ = main.o
|
||||||
OBJCOPY := avr-objcopy
|
MCU_TARGET = atmega88
|
||||||
OBJDUMP := avr-objdump
|
OPTIMIZE = -Os
|
||||||
SIZE := avr-size
|
|
||||||
|
|
||||||
TARGET = twiboot
|
DEFS =
|
||||||
SOURCE = $(wildcard *.c)
|
LIBS =
|
||||||
|
|
||||||
# select MCU
|
# Override is only needed by avr-lib build system.
|
||||||
MCU = attiny85
|
override CFLAGS = -g -Wall $(OPTIMIZE) -mmcu=$(MCU_TARGET) $(DEFS)
|
||||||
|
override LDFLAGS = -Wl,-Map,$(PRG).map,--section-start=.text=0x1C00
|
||||||
|
|
||||||
AVRDUDE_PROG := -c avr910 -b 115200 -P /dev/ttyUSB0
|
CC = avr-gcc
|
||||||
#AVRDUDE_PROG := -c dragon_isp -P usb
|
OBJCOPY = avr-objcopy
|
||||||
|
OBJDUMP = avr-objdump
|
||||||
|
SIZE = avr-size
|
||||||
|
|
||||||
# ---------------------------------------------------------------------------
|
all: $(PRG).elf lst text
|
||||||
|
$(SIZE) -x -A $(PRG).elf
|
||||||
|
|
||||||
ifeq ($(MCU), atmega8)
|
$(PRG).elf: $(OBJ)
|
||||||
# atmega8:
|
$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^ $(LIBS)
|
||||||
# Fuse L: 0x84 (8Mhz internal RC-Osz., 2.7V BOD)
|
|
||||||
# Fuse H: 0xda (512 words bootloader)
|
|
||||||
AVRDUDE_MCU=m8
|
|
||||||
AVRDUDE_FUSES=lfuse:w:0x84:m hfuse:w:0xda:m
|
|
||||||
|
|
||||||
BOOTLOADER_START=0x1C00
|
|
||||||
endif
|
|
||||||
|
|
||||||
ifeq ($(MCU), atmega88)
|
|
||||||
# atmega88:
|
|
||||||
# Fuse L: 0xc2 (8Mhz internal RC-Osz.)
|
|
||||||
# Fuse H: 0xdd (2.7V BOD)
|
|
||||||
# Fuse E: 0xfa (512 words bootloader)
|
|
||||||
AVRDUDE_MCU=m88
|
|
||||||
AVRDUDE_FUSES=lfuse:w:0xc2:m hfuse:w:0xdd:m efuse:w:0xfa:m
|
|
||||||
|
|
||||||
BOOTLOADER_START=0x1C00
|
|
||||||
endif
|
|
||||||
|
|
||||||
ifeq ($(MCU), atmega168)
|
|
||||||
# atmega168:
|
|
||||||
# Fuse L: 0xc2 (8Mhz internal RC-Osz.)
|
|
||||||
# Fuse H: 0xdd (2.7V BOD)
|
|
||||||
# Fuse E: 0xfa (512 words bootloader)
|
|
||||||
AVRDUDE_MCU=m168 -F
|
|
||||||
AVRDUDE_FUSES=lfuse:w:0xc2:m hfuse:w:0xdd:m efuse:w:0xfa:m
|
|
||||||
|
|
||||||
BOOTLOADER_START=0x3C00
|
|
||||||
endif
|
|
||||||
|
|
||||||
ifeq ($(MCU), atmega328p)
|
|
||||||
# atmega328p:
|
|
||||||
# Fuse L: 0xc2 (8Mhz internal RC-Osz.)
|
|
||||||
# Fuse H: 0xdc (512 words bootloader)
|
|
||||||
# Fuse E: 0xfd (2.7V BOD)
|
|
||||||
AVRDUDE_MCU=m328p -F
|
|
||||||
AVRDUDE_FUSES=lfuse:w:0xc2:m hfuse:w:0xdc:m efuse:w:0xfd:m
|
|
||||||
|
|
||||||
BOOTLOADER_START=0x7C00
|
|
||||||
endif
|
|
||||||
|
|
||||||
ifeq ($(MCU), attiny85)
|
|
||||||
# attiny85:
|
|
||||||
# Fuse L: 0xe2 (8Mhz internal RC-Osz.)
|
|
||||||
# Fuse H: 0xdd (2.7V BOD)
|
|
||||||
# Fuse E: 0xfe (self programming enable)
|
|
||||||
AVRDUDE_MCU=t85
|
|
||||||
AVRDUDE_FUSES=lfuse:w:0xe2:m hfuse:w:0xdd:m efuse:w:0xfe:m
|
|
||||||
|
|
||||||
BOOTLOADER_START=0x1C00
|
|
||||||
CFLAGS_TARGET=-DUSE_CLOCKSTRETCH=1 -DVIRTUAL_BOOT_SECTION=1
|
|
||||||
endif
|
|
||||||
|
|
||||||
# ---------------------------------------------------------------------------
|
|
||||||
|
|
||||||
CFLAGS = -pipe -g -Os -mmcu=$(MCU) -Wall -fdata-sections -ffunction-sections
|
|
||||||
CFLAGS += -Wa,-adhlns=$(*F).lst -DBOOTLOADER_START=$(BOOTLOADER_START) $(CFLAGS_TARGET)
|
|
||||||
LDFLAGS = -Wl,-Map,$(@:.elf=.map),--cref,--relax,--gc-sections,--section-start=.text=$(BOOTLOADER_START)
|
|
||||||
LDFLAGS += -nostartfiles
|
|
||||||
|
|
||||||
# ---------------------------------------------------------------------------
|
|
||||||
|
|
||||||
$(TARGET): $(TARGET).elf
|
|
||||||
@$(SIZE) -B -x --mcu=$(MCU) $<
|
|
||||||
|
|
||||||
$(TARGET).elf: $(SOURCE:.c=.o)
|
|
||||||
@echo " Linking file: $@"
|
|
||||||
@$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^
|
|
||||||
@$(OBJDUMP) -h -S $@ > $(@:.elf=.lss)
|
|
||||||
@$(OBJCOPY) -j .text -j .data -O ihex $@ $(@:.elf=.hex)
|
|
||||||
@$(OBJCOPY) -j .text -j .data -O binary $@ $(@:.elf=.bin)
|
|
||||||
|
|
||||||
%.o: %.c $(MAKEFILE_LIST)
|
|
||||||
@echo " Building file: $<"
|
|
||||||
@$(CC) $(CFLAGS) -o $@ -c $<
|
|
||||||
|
|
||||||
clean:
|
clean:
|
||||||
rm -rf $(SOURCE:.c=.o) $(SOURCE:.c=.lst) $(addprefix $(TARGET), .elf .map .lss .hex .bin)
|
rm -rf *.o *.lst *.map $(PRG).elf *.hex *.bin
|
||||||
|
|
||||||
install: $(TARGET).elf
|
lst: $(PRG).lst
|
||||||
avrdude $(AVRDUDE_PROG) -p $(AVRDUDE_MCU) -U flash:w:$(<:.elf=.hex)
|
|
||||||
|
%.lst: %.elf
|
||||||
|
$(OBJDUMP) -h -S $< > $@
|
||||||
|
|
||||||
|
text: hex bin
|
||||||
|
|
||||||
|
hex: $(PRG).hex
|
||||||
|
bin: $(PRG).bin
|
||||||
|
|
||||||
|
%.hex: %.elf
|
||||||
|
$(OBJCOPY) -j .text -j .data -O ihex $< $@
|
||||||
|
|
||||||
|
%.bin: %.elf
|
||||||
|
$(OBJCOPY) -j .text -j .data -O binary $< $@
|
||||||
|
|
||||||
|
install: text
|
||||||
|
avrdude -c dragon_isp -P usb -p m88 -U flash:w:$(PRG).hex
|
||||||
|
|
||||||
fuses:
|
fuses:
|
||||||
avrdude $(AVRDUDE_PROG) -p $(AVRDUDE_MCU) $(patsubst %,-U %, $(AVRDUDE_FUSES))
|
avrdude -c dragon_isp -P usb -p m88 -U lfuse:w:0xc2:m -U hfuse:w:0xdd:m -U efuse:w:0xfa:m
|
||||||
|
119
README.md
119
README.md
@ -1,119 +0,0 @@
|
|||||||
# twiboot - a TWI / I2C bootloader for AVR MCUs ##
|
|
||||||
twiboot is a simple/small bootloader for AVR MCUs written in C. It uses the integrated TWI or USI peripheral of the controller to implement a I2C slave.
|
|
||||||
It was originally created to update I2C controlled BLMCs (Brushless Motor Controller) without an AVR ISP adapter.
|
|
||||||
|
|
||||||
twiboot acts as a slave device on a TWI/I2C bus and allows reading/writing of the internal flash memory.
|
|
||||||
As a compile time option (EEPROM_SUPPORT) twiboot also allows reading/writing of the whole internal EEPROM memory.
|
|
||||||
The bootloader is not able to update itself (only application flash memory region accessible).
|
|
||||||
|
|
||||||
Currently the following AVR MCUs are supported:
|
|
||||||
|
|
||||||
AVR MCU | Flash bytes used (.text + .data) | Bootloader region size
|
|
||||||
--- | --- | ---
|
|
||||||
attiny85 | 954 (0x3BA) | 512 words
|
|
||||||
atmega8 | 786 (0x312) | 512 words
|
|
||||||
atmega88 | 810 (0x32A) | 512 words
|
|
||||||
atmega168 | 810 (0x32A) | 512 words
|
|
||||||
atmega328p | 810 (0x32A) | 512 words
|
|
||||||
|
|
||||||
(Compiled on Ubuntu 18.04 LTS (gcc 5.4.0 / avr-libc 2.0.0) with EEPROM and LED support)
|
|
||||||
|
|
||||||
|
|
||||||
## Operation ##
|
|
||||||
twiboot is installed in the bootloader section and executed directly after reset (BOOTRST fuse is programmed).
|
|
||||||
For MCUs without bootloader section see [Virtual bootloader section](#virtual-bootloader-section) below.
|
|
||||||
|
|
||||||
While running, twiboot configures the TWI/USI peripheral as slave device and waits for valid protocol messages
|
|
||||||
directed to its address on the TWI/I2C bus. The slave address is configured during compile time of twiboot.
|
|
||||||
When receiving no messages for 1000ms after reset, the bootloader exits and executes the main application at address 0x0000.
|
|
||||||
|
|
||||||
A TWI/I2C master can use the protocol to
|
|
||||||
- abort the boot timeout
|
|
||||||
- query information about the device (bootloader version, AVR signature bytes, flash/eeprom size, flash page size)
|
|
||||||
- read internal flash / eeprom memory (byte wise)
|
|
||||||
- write the internal flash (page wise)
|
|
||||||
- write the internal eeprom (byte wise)
|
|
||||||
- exit the bootloader and start the application
|
|
||||||
|
|
||||||
As a compile time option (LED_SUPPORT) twiboot can output its state with two LEDs.
|
|
||||||
One LED will flash with a frequency of 20Hz while twiboot is active (including boot wait time).
|
|
||||||
A second LED will flash when the bootloader is addressed on the TWI/I2C bus.
|
|
||||||
|
|
||||||
|
|
||||||
### Virtual Bootloader Section ###
|
|
||||||
For MCUs without bootloader section twiboot will patch the vector table on the fly during flash programming to stay active.
|
|
||||||
The reset vector is patched to execute twiboot instead of the application code.
|
|
||||||
|
|
||||||
Another vector entry will be patched to store the original entry point of the application.
|
|
||||||
This vector entry is overridden and MUST NOT be used by the application.
|
|
||||||
twiboot uses this vector to start the application after the initial timeout.
|
|
||||||
|
|
||||||
This live patching changes the content of the vector table, which would result in a verification error after programming.
|
|
||||||
To counter this kind of error, twiboot caches the original vector table entries in RAM and return those on a read command.
|
|
||||||
The real content of the vector table is only returned after a reset.
|
|
||||||
|
|
||||||
|
|
||||||
## Build and install twiboot ##
|
|
||||||
twiboot uses gcc, avr-libc and GNU Make for building, avrdude is used for flashing the MCU.
|
|
||||||
The build and install procedures are only tested under linux.
|
|
||||||
|
|
||||||
The selection of the target MCU and the programming interface can be found in the Makefile,
|
|
||||||
TWI/I2C slave address and optional components (EEPROM / LED support) are configured
|
|
||||||
in the main.c source.
|
|
||||||
|
|
||||||
To build twiboot for the selected target:
|
|
||||||
``` shell
|
|
||||||
$ make
|
|
||||||
```
|
|
||||||
|
|
||||||
To install (flash download) twiboot with avrdude on the target:
|
|
||||||
``` shell
|
|
||||||
$ make install
|
|
||||||
```
|
|
||||||
|
|
||||||
Set AVR fuses with avrdude on the target (internal RC-Osz, enable BOD, enable BOOTRST):
|
|
||||||
``` shell
|
|
||||||
$ make fuses
|
|
||||||
```
|
|
||||||
|
|
||||||
|
|
||||||
## TWI/I2C Protocol ##
|
|
||||||
A TWI/I2C master can use the following protocol for accessing the bootloader.
|
|
||||||
|
|
||||||
Function | TWI/I2C data | Comment
|
|
||||||
--- | --- | ---
|
|
||||||
Abort boot timeout | **SLA+W**, 0x00, **STO** |
|
|
||||||
Show bootloader version | **SLA+W**, 0x01, **SLA+R**, {16 bytes}, **STO** | ASCII, not null terminated
|
|
||||||
Start application | **SLA+W**, 0x01, 0x80, **STO** |
|
|
||||||
Read chip info | **SLA+W**, 0x02, 0x00, 0x00, 0x00, **SLA+R**, {8 bytes}, **STO** | 3byte signature, 1byte page size, 2byte flash size, 2byte eeprom size
|
|
||||||
Read 1+ flash bytes | **SLA+W**, 0x02, 0x01, addrh, addrl, **SLA+R**, {* bytes}, **STO** |
|
|
||||||
Read 1+ eeprom bytes | **SLA+W**, 0x02, 0x02, addrh, addrl, **SLA+R**, {* bytes}, **STO** |
|
|
||||||
Write one flash page | **SLA+W**, 0x02, 0x01, addrh, addrl, {* bytes}, **STO** | page size as indicated in chip info
|
|
||||||
Write 1+ eeprom bytes | **SLA+W**, 0x02, 0x02, addrh, addrl, {* bytes}, **STO** | write 0 < n < page size bytes at once
|
|
||||||
|
|
||||||
**SLA+R** means Start Condition, Slave Address, Read Access
|
|
||||||
|
|
||||||
**SLA+W** means Start Condition, Slave Address, Write Access
|
|
||||||
|
|
||||||
**STO** means Stop Condition
|
|
||||||
|
|
||||||
A flash page / eeprom write is only triggered after the Stop Condition.
|
|
||||||
During the write process twiboot will NOT acknowledge its slave address.
|
|
||||||
|
|
||||||
The multiboot_tool repository contains a simple linux application that uses
|
|
||||||
this protocol to access the bootloader over linux i2c device.
|
|
||||||
|
|
||||||
The ispprog programming adapter can also be used as a avr910/butterfly to twiboot protocol bridge.
|
|
||||||
|
|
||||||
|
|
||||||
## TWI/I2C Clockstretching ##
|
|
||||||
While a write is in progress twiboot will not respond on the TWI/I2C bus and the
|
|
||||||
TWI/I2C master needs to retry/poll the slave address until the write has completed.
|
|
||||||
|
|
||||||
As a compile time option (USE_CLOCKSTRETCH) the previous behavior of twiboot can be restored:
|
|
||||||
TWI/I2C Clockstretching is then used to inform the master of the duration of the write.
|
|
||||||
Please note that there are some TWI/I2C masters that do not support clockstretching.
|
|
||||||
|
|
||||||
|
|
||||||
## Development ##
|
|
||||||
Issue reports, feature requests, patches or simply success stories are much appreciated.
|
|
Loading…
Reference in New Issue
Block a user