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Add support for producing UF2-format binaries. (#12435)

* First stab at enabling builds of UF2-format binaries.

* Add description on producing a UF2 file.
This commit is contained in:
Nick Brassel 2021-04-06 16:39:15 +10:00 committed by GitHub
parent 3ce8c9fc8f
commit 64a0f5a659
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
6 changed files with 373 additions and 8 deletions

1
.gitignore vendored
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@ -5,6 +5,7 @@
*.eep *.eep
*.elf *.elf
*.hex *.hex
*.uf2
*.qmk *.qmk
!util/bootloader.hex !util/bootloader.hex
!quantum/tools/eeprom_reset.hex !quantum/tools/eeprom_reset.hex

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@ -93,8 +93,8 @@ clean:
.PHONY: distclean .PHONY: distclean
distclean: clean distclean: clean
echo -n 'Deleting *.bin and *.hex ... ' echo -n 'Deleting *.bin, *.hex, and *.uf2 ... '
rm -f *.bin *.hex rm -f *.bin *.hex *.uf2
echo 'done.' echo 'done.'
#Compatibility with the old make variables, anything you specify directly on the command line #Compatibility with the old make variables, anything you specify directly on the command line

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@ -47,10 +47,12 @@ MSG_SIZE_AFTER = Size after:
MSG_COFF = Converting to AVR COFF: MSG_COFF = Converting to AVR COFF:
MSG_EXTENDED_COFF = Converting to AVR Extended COFF: MSG_EXTENDED_COFF = Converting to AVR Extended COFF:
MSG_FLASH = Creating load file for flashing: MSG_FLASH = Creating load file for flashing:
MSG_UF2 = Creating UF2 file for deployment:
MSG_EEPROM = Creating load file for EEPROM: MSG_EEPROM = Creating load file for EEPROM:
MSG_BIN = Creating binary load file for flashing: MSG_BIN = Creating binary load file for flashing:
MSG_EXTENDED_LISTING = Creating Extended Listing: MSG_EXTENDED_LISTING = Creating Extended Listing:
MSG_SYMBOL_TABLE = Creating Symbol Table: MSG_SYMBOL_TABLE = Creating Symbol Table:
MSG_EXECUTING = Executing:
MSG_LINKING = Linking: MSG_LINKING = Linking:
MSG_COMPILING = Compiling: MSG_COMPILING = Compiling:
MSG_COMPILING_CXX = Compiling: MSG_COMPILING_CXX = Compiling:

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@ -139,6 +139,9 @@ ifneq ($(findstring STM32F042, $(MCU)),)
# Options to pass to dfu-util when flashing # Options to pass to dfu-util when flashing
DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave
DFU_SUFFIX_ARGS ?= -v 0483 -p DF11 DFU_SUFFIX_ARGS ?= -v 0483 -p DF11
# UF2 settings
UF2_FAMILY ?= STM32F0
endif endif
ifneq ($(findstring STM32F072, $(MCU)),) ifneq ($(findstring STM32F072, $(MCU)),)
@ -172,6 +175,9 @@ ifneq ($(findstring STM32F072, $(MCU)),)
# Options to pass to dfu-util when flashing # Options to pass to dfu-util when flashing
DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave
DFU_SUFFIX_ARGS ?= -v 0483 -p DF11 DFU_SUFFIX_ARGS ?= -v 0483 -p DF11
# UF2 settings
UF2_FAMILY ?= STM32F0
endif endif
ifneq ($(findstring STM32F103, $(MCU)),) ifneq ($(findstring STM32F103, $(MCU)),)
@ -205,6 +211,9 @@ ifneq ($(findstring STM32F103, $(MCU)),)
# Options to pass to dfu-util when flashing # Options to pass to dfu-util when flashing
DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave
DFU_SUFFIX_ARGS ?= -v 0483 -p DF11 DFU_SUFFIX_ARGS ?= -v 0483 -p DF11
# UF2 settings
UF2_FAMILY ?= STM32F1
endif endif
ifneq ($(findstring STM32F303, $(MCU)),) ifneq ($(findstring STM32F303, $(MCU)),)
@ -238,6 +247,9 @@ ifneq ($(findstring STM32F303, $(MCU)),)
# Options to pass to dfu-util when flashing # Options to pass to dfu-util when flashing
DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave
DFU_SUFFIX_ARGS ?= -v 0483 -p DF11 DFU_SUFFIX_ARGS ?= -v 0483 -p DF11
# UF2 settings
UF2_FAMILY ?= STM32F3
endif endif
ifneq ($(findstring STM32F401, $(MCU)),) ifneq ($(findstring STM32F401, $(MCU)),)
@ -271,6 +283,9 @@ ifneq ($(findstring STM32F401, $(MCU)),)
# Options to pass to dfu-util when flashing # Options to pass to dfu-util when flashing
DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave
DFU_SUFFIX_ARGS ?= -v 0483 -p DF11 DFU_SUFFIX_ARGS ?= -v 0483 -p DF11
# UF2 settings
UF2_FAMILY ?= STM32F4
endif endif
ifneq ($(findstring STM32F411, $(MCU)),) ifneq ($(findstring STM32F411, $(MCU)),)
@ -304,6 +319,9 @@ ifneq ($(findstring STM32F411, $(MCU)),)
# Options to pass to dfu-util when flashing # Options to pass to dfu-util when flashing
DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave
DFU_SUFFIX_ARGS ?= -v 0483 -p DF11 DFU_SUFFIX_ARGS ?= -v 0483 -p DF11
# UF2 settings
UF2_FAMILY ?= STM32F4
endif endif
ifneq ($(findstring STM32G431, $(MCU)),) ifneq ($(findstring STM32G431, $(MCU)),)
@ -337,6 +355,9 @@ ifneq ($(findstring STM32G431, $(MCU)),)
# Options to pass to dfu-util when flashing # Options to pass to dfu-util when flashing
DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave
DFU_SUFFIX_ARGS ?= -v 0483 -p DF11 DFU_SUFFIX_ARGS ?= -v 0483 -p DF11
# UF2 settings
UF2_FAMILY ?= STM32G4
endif endif
ifneq ($(findstring STM32G474, $(MCU)),) ifneq ($(findstring STM32G474, $(MCU)),)
@ -370,6 +391,9 @@ ifneq ($(findstring STM32G474, $(MCU)),)
# Options to pass to dfu-util when flashing # Options to pass to dfu-util when flashing
DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave DFU_ARGS ?= -d 0483:DF11 -a 0 -s 0x08000000:leave
DFU_SUFFIX_ARGS ?= -v 0483 -p DF11 DFU_SUFFIX_ARGS ?= -v 0483 -p DF11
# UF2 settings
UF2_FAMILY ?= STM32G4
endif endif
ifneq (,$(filter $(MCU),at90usb162 atmega16u2 atmega32u2 atmega16u4 atmega32u4 at90usb646 at90usb647 at90usb1286 at90usb1287)) ifneq (,$(filter $(MCU),at90usb162 atmega16u2 atmega32u2 atmega16u4 atmega32u4 at90usb646 at90usb647 at90usb1286 at90usb1287))

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@ -223,6 +223,12 @@ ifneq ($(filter Darwin FreeBSD,$(shell uname -s)),)
MD5SUM = md5 MD5SUM = md5
endif endif
# UF2 format settings
# To produce a UF2 file in your build, add to your keyboard's rules.mk:
# FIRMWARE_FORMAT = uf2
UF2CONV = $(TOP_DIR)/util/uf2conv.py
UF2_FAMILY ?= 0x0
# Compiler flags to generate dependency files. # Compiler flags to generate dependency files.
#GENDEPFLAGS = -MMD -MP -MF .dep/$(@F).d #GENDEPFLAGS = -MMD -MP -MF .dep/$(@F).d
GENDEPFLAGS = -MMD -MP -MF $(patsubst %.o,%.td,$@) GENDEPFLAGS = -MMD -MP -MF $(patsubst %.o,%.td,$@)
@ -255,6 +261,7 @@ DFU_SUFFIX_ARGS ?=
elf: $(BUILD_DIR)/$(TARGET).elf elf: $(BUILD_DIR)/$(TARGET).elf
hex: $(BUILD_DIR)/$(TARGET).hex hex: $(BUILD_DIR)/$(TARGET).hex
uf2: $(BUILD_DIR)/$(TARGET).uf2
cpfirmware: $(FIRMWARE_FORMAT) cpfirmware: $(FIRMWARE_FORMAT)
$(SILENT) || printf "Copying $(TARGET).$(FIRMWARE_FORMAT) to qmk_firmware folder" | $(AWK_CMD) $(SILENT) || printf "Copying $(TARGET).$(FIRMWARE_FORMAT) to qmk_firmware folder" | $(AWK_CMD)
$(COPY) $(BUILD_DIR)/$(TARGET).$(FIRMWARE_FORMAT) $(TARGET).$(FIRMWARE_FORMAT) && $(PRINT_OK) $(COPY) $(BUILD_DIR)/$(TARGET).$(FIRMWARE_FORMAT) $(TARGET).$(FIRMWARE_FORMAT) && $(PRINT_OK)
@ -283,32 +290,44 @@ gccversion :
# Create final output files (.hex, .eep) from ELF output file. # Create final output files (.hex, .eep) from ELF output file.
%.hex: %.elf %.hex: %.elf
@$(SILENT) || printf "$(MSG_FLASH) $@" | $(AWK_CMD)
$(eval CMD=$(HEX) $< $@) $(eval CMD=$(HEX) $< $@)
#@$(SILENT) || printf "$(MSG_EXECUTING) '$(CMD)':\n"
@$(SILENT) || printf "$(MSG_FLASH) $@" | $(AWK_CMD)
@$(BUILD_CMD)
%.uf2: %.hex
$(eval CMD=$(UF2CONV) $(BUILD_DIR)/$(TARGET).hex -o $(BUILD_DIR)/$(TARGET).uf2 -c -f $(UF2_FAMILY) >/dev/null 2>&1)
#@$(SILENT) || printf "$(MSG_EXECUTING) '$(CMD)':\n"
@$(SILENT) || printf "$(MSG_UF2) $@" | $(AWK_CMD)
@$(BUILD_CMD) @$(BUILD_CMD)
%.eep: %.elf %.eep: %.elf
@$(SILENT) || printf "$(MSG_EEPROM) $@" | $(AWK_CMD)
$(eval CMD=$(EEP) $< $@ || exit 0) $(eval CMD=$(EEP) $< $@ || exit 0)
#@$(SILENT) || printf "$(MSG_EXECUTING) '$(CMD)':\n"
@$(SILENT) || printf "$(MSG_EEPROM) $@" | $(AWK_CMD)
@$(BUILD_CMD) @$(BUILD_CMD)
# Create extended listing file from ELF output file. # Create extended listing file from ELF output file.
%.lss: %.elf %.lss: %.elf
@$(SILENT) || printf "$(MSG_EXTENDED_LISTING) $@" | $(AWK_CMD)
$(eval CMD=$(OBJDUMP) -h -S -z $< > $@) $(eval CMD=$(OBJDUMP) -h -S -z $< > $@)
#@$(SILENT) || printf "$(MSG_EXECUTING) '$(CMD)':\n"
@$(SILENT) || printf "$(MSG_EXTENDED_LISTING) $@" | $(AWK_CMD)
@$(BUILD_CMD) @$(BUILD_CMD)
# Create a symbol table from ELF output file. # Create a symbol table from ELF output file.
%.sym: %.elf %.sym: %.elf
@$(SILENT) || printf "$(MSG_SYMBOL_TABLE) $@" | $(AWK_CMD)
$(eval CMD=$(NM) -n $< > $@ ) $(eval CMD=$(NM) -n $< > $@ )
#@$(SILENT) || printf "$(MSG_EXECUTING) '$(CMD)':\n"
@$(SILENT) || printf "$(MSG_SYMBOL_TABLE) $@" | $(AWK_CMD)
@$(BUILD_CMD) @$(BUILD_CMD)
%.bin: %.elf %.bin: %.elf
@$(SILENT) || printf "$(MSG_BIN) $@" | $(AWK_CMD)
$(eval CMD=$(BIN) $< $@ || exit 0) $(eval CMD=$(BIN) $< $@ || exit 0)
#@$(SILENT) || printf "$(MSG_EXECUTING) '$(CMD)':\n"
@$(SILENT) || printf "$(MSG_BIN) $@" | $(AWK_CMD)
@$(BUILD_CMD) @$(BUILD_CMD)
if [ ! -z "$(DFU_SUFFIX_ARGS)" ]; then \ if [ ! -z "$(DFU_SUFFIX_ARGS)" ]; then \
#$(SILENT) || printf "$(MSG_EXECUTING) '$(DFU_SUFFIX) $(DFU_SUFFIX_ARGS) -a $(BUILD_DIR)/$(TARGET).bin 1>/dev/null':\n" ;\
$(DFU_SUFFIX) $(DFU_SUFFIX_ARGS) -a $(BUILD_DIR)/$(TARGET).bin 1>/dev/null ;\ $(DFU_SUFFIX) $(DFU_SUFFIX_ARGS) -a $(BUILD_DIR)/$(TARGET).bin 1>/dev/null ;\
fi fi
$(COPY) $(BUILD_DIR)/$(TARGET).bin $(TARGET).bin; $(COPY) $(BUILD_DIR)/$(TARGET).bin $(TARGET).bin;
@ -476,7 +495,7 @@ $(eval $(foreach OUTPUT,$(OUTPUTS),$(shell mkdir -p $(OUTPUT) 2>/dev/null)))
# Listing of phony targets. # Listing of phony targets.
.PHONY : all dump_vars finish sizebefore sizeafter qmkversion \ .PHONY : all dump_vars finish sizebefore sizeafter qmkversion \
gccversion build elf hex eep lss sym coff extcoff \ gccversion build elf hex uf2 eep lss sym coff extcoff \
clean clean_list debug gdb-config show_path \ clean clean_list debug gdb-config show_path \
program teensy dfu dfu-ee dfu-start \ program teensy dfu dfu-ee dfu-start \
flash dfu-split-left dfu-split-right \ flash dfu-split-left dfu-split-right \

319
util/uf2conv.py Executable file
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@ -0,0 +1,319 @@
#!/usr/bin/env python3
import sys
import struct
import subprocess
import re
import os
import os.path
import argparse
UF2_MAGIC_START0 = 0x0A324655 # "UF2\n"
UF2_MAGIC_START1 = 0x9E5D5157 # Randomly selected
UF2_MAGIC_END = 0x0AB16F30 # Ditto
families = {
'SAMD21': 0x68ed2b88,
'SAML21': 0x1851780a,
'SAMD51': 0x55114460,
'NRF52': 0x1b57745f,
'STM32F0': 0x647824b6,
'STM32F1': 0x5ee21072,
'STM32F2': 0x5d1a0a2e,
'STM32F3': 0x6b846188,
'STM32F4': 0x57755a57,
'STM32F7': 0x53b80f00,
'STM32G0': 0x300f5633,
'STM32G4': 0x4c71240a,
'STM32H7': 0x6db66082,
'STM32L0': 0x202e3a91,
'STM32L1': 0x1e1f432d,
'STM32L4': 0x00ff6919,
'STM32L5': 0x04240bdf,
'STM32WB': 0x70d16653,
'STM32WL': 0x21460ff0,
'ATMEGA32': 0x16573617,
'MIMXRT10XX': 0x4FB2D5BD,
'LPC55': 0x2abc77ec,
'GD32F350': 0x31D228C6,
'ESP32S2': 0xbfdd4eee,
'RP2040': 0xe48bff56
}
INFO_FILE = "/INFO_UF2.TXT"
appstartaddr = 0x2000
familyid = 0x0
def is_uf2(buf):
w = struct.unpack("<II", buf[0:8])
return w[0] == UF2_MAGIC_START0 and w[1] == UF2_MAGIC_START1
def is_hex(buf):
try:
w = buf[0:30].decode("utf-8")
except UnicodeDecodeError:
return False
if w[0] == ':' and re.match(b"^[:0-9a-fA-F\r\n]+$", buf):
return True
return False
def convert_from_uf2(buf):
global appstartaddr
numblocks = len(buf) // 512
curraddr = None
outp = []
for blockno in range(numblocks):
ptr = blockno * 512
block = buf[ptr:ptr + 512]
hd = struct.unpack(b"<IIIIIIII", block[0:32])
if hd[0] != UF2_MAGIC_START0 or hd[1] != UF2_MAGIC_START1:
print("Skipping block at " + ptr + "; bad magic")
continue
if hd[2] & 1:
# NO-flash flag set; skip block
continue
datalen = hd[4]
if datalen > 476:
assert False, "Invalid UF2 data size at " + ptr
newaddr = hd[3]
if curraddr == None:
appstartaddr = newaddr
curraddr = newaddr
padding = newaddr - curraddr
if padding < 0:
assert False, "Block out of order at " + ptr
if padding > 10*1024*1024:
assert False, "More than 10M of padding needed at " + ptr
if padding % 4 != 0:
assert False, "Non-word padding size at " + ptr
while padding > 0:
padding -= 4
outp += b"\x00\x00\x00\x00"
outp.append(block[32 : 32 + datalen])
curraddr = newaddr + datalen
return b"".join(outp)
def convert_to_carray(file_content):
outp = "const unsigned long bindata_len = %d;\n" % len(file_content)
outp += "const unsigned char bindata[] __attribute__((aligned(16))) = {"
for i in range(len(file_content)):
if i % 16 == 0:
outp += "\n"
outp += "0x%02x, " % file_content[i]
outp += "\n};\n"
return bytes(outp, "utf-8")
def convert_to_uf2(file_content):
global familyid
datapadding = b""
while len(datapadding) < 512 - 256 - 32 - 4:
datapadding += b"\x00\x00\x00\x00"
numblocks = (len(file_content) + 255) // 256
outp = []
for blockno in range(numblocks):
ptr = 256 * blockno
chunk = file_content[ptr:ptr + 256]
flags = 0x0
if familyid:
flags |= 0x2000
hd = struct.pack(b"<IIIIIIII",
UF2_MAGIC_START0, UF2_MAGIC_START1,
flags, ptr + appstartaddr, 256, blockno, numblocks, familyid)
while len(chunk) < 256:
chunk += b"\x00"
block = hd + chunk + datapadding + struct.pack(b"<I", UF2_MAGIC_END)
assert len(block) == 512
outp.append(block)
return b"".join(outp)
class Block:
def __init__(self, addr):
self.addr = addr
self.bytes = bytearray(256)
def encode(self, blockno, numblocks):
global familyid
flags = 0x0
if familyid:
flags |= 0x2000
hd = struct.pack("<IIIIIIII",
UF2_MAGIC_START0, UF2_MAGIC_START1,
flags, self.addr, 256, blockno, numblocks, familyid)
hd += self.bytes[0:256]
while len(hd) < 512 - 4:
hd += b"\x00"
hd += struct.pack("<I", UF2_MAGIC_END)
return hd
def convert_from_hex_to_uf2(buf):
global appstartaddr
appstartaddr = None
upper = 0
currblock = None
blocks = []
for line in buf.split('\n'):
if line[0] != ":":
continue
i = 1
rec = []
while i < len(line) - 1:
rec.append(int(line[i:i+2], 16))
i += 2
tp = rec[3]
if tp == 4:
upper = ((rec[4] << 8) | rec[5]) << 16
elif tp == 2:
upper = ((rec[4] << 8) | rec[5]) << 4
assert (upper & 0xffff) == 0
elif tp == 1:
break
elif tp == 0:
addr = upper | (rec[1] << 8) | rec[2]
if appstartaddr == None:
appstartaddr = addr
i = 4
while i < len(rec) - 1:
if not currblock or currblock.addr & ~0xff != addr & ~0xff:
currblock = Block(addr & ~0xff)
blocks.append(currblock)
currblock.bytes[addr & 0xff] = rec[i]
addr += 1
i += 1
numblocks = len(blocks)
resfile = b""
for i in range(0, numblocks):
resfile += blocks[i].encode(i, numblocks)
return resfile
def to_str(b):
return b.decode("utf-8")
def get_drives():
drives = []
if sys.platform == "win32":
r = subprocess.check_output(["wmic", "PATH", "Win32_LogicalDisk",
"get", "DeviceID,", "VolumeName,",
"FileSystem,", "DriveType"])
for line in to_str(r).split('\n'):
words = re.split('\s+', line)
if len(words) >= 3 and words[1] == "2" and words[2] == "FAT":
drives.append(words[0])
else:
rootpath = "/media"
if sys.platform == "darwin":
rootpath = "/Volumes"
elif sys.platform == "linux":
tmp = rootpath + "/" + os.environ["USER"]
if os.path.isdir(tmp):
rootpath = tmp
for d in os.listdir(rootpath):
drives.append(os.path.join(rootpath, d))
def has_info(d):
try:
return os.path.isfile(d + INFO_FILE)
except:
return False
return list(filter(has_info, drives))
def board_id(path):
with open(path + INFO_FILE, mode='r') as file:
file_content = file.read()
return re.search("Board-ID: ([^\r\n]*)", file_content).group(1)
def list_drives():
for d in get_drives():
print(d, board_id(d))
def write_file(name, buf):
with open(name, "wb") as f:
f.write(buf)
print("Wrote %d bytes to %s" % (len(buf), name))
def main():
global appstartaddr, familyid
def error(msg):
print(msg)
sys.exit(1)
parser = argparse.ArgumentParser(description='Convert to UF2 or flash directly.')
parser.add_argument('input', metavar='INPUT', type=str, nargs='?',
help='input file (HEX, BIN or UF2)')
parser.add_argument('-b' , '--base', dest='base', type=str,
default="0x2000",
help='set base address of application for BIN format (default: 0x2000)')
parser.add_argument('-o' , '--output', metavar="FILE", dest='output', type=str,
help='write output to named file; defaults to "flash.uf2" or "flash.bin" where sensible')
parser.add_argument('-d' , '--device', dest="device_path",
help='select a device path to flash')
parser.add_argument('-l' , '--list', action='store_true',
help='list connected devices')
parser.add_argument('-c' , '--convert', action='store_true',
help='do not flash, just convert')
parser.add_argument('-D' , '--deploy', action='store_true',
help='just flash, do not convert')
parser.add_argument('-f' , '--family', dest='family', type=str,
default="0x0",
help='specify familyID - number or name (default: 0x0)')
parser.add_argument('-C' , '--carray', action='store_true',
help='convert binary file to a C array, not UF2')
args = parser.parse_args()
appstartaddr = int(args.base, 0)
if args.family.upper() in families:
familyid = families[args.family.upper()]
else:
try:
familyid = int(args.family, 0)
except ValueError:
error("Family ID needs to be a number or one of: " + ", ".join(families.keys()))
if args.list:
list_drives()
else:
if not args.input:
error("Need input file")
with open(args.input, mode='rb') as f:
inpbuf = f.read()
from_uf2 = is_uf2(inpbuf)
ext = "uf2"
if args.deploy:
outbuf = inpbuf
elif from_uf2:
outbuf = convert_from_uf2(inpbuf)
ext = "bin"
elif is_hex(inpbuf):
outbuf = convert_from_hex_to_uf2(inpbuf.decode("utf-8"))
elif args.carray:
outbuf = convert_to_carray(inpbuf)
ext = "h"
else:
outbuf = convert_to_uf2(inpbuf)
print("Converting to %s, output size: %d, start address: 0x%x" %
(ext, len(outbuf), appstartaddr))
if args.convert or ext != "uf2":
drives = []
if args.output == None:
args.output = "flash." + ext
else:
drives = get_drives()
if args.output:
write_file(args.output, outbuf)
else:
if len(drives) == 0:
error("No drive to deploy.")
for d in drives:
print("Flashing %s (%s)" % (d, board_id(d)))
write_file(d + "/NEW.UF2", outbuf)
if __name__ == "__main__":
main()