Moved build artifacts into root build folder

The intermediate files used for build (.o, .a ...) are still
in subfolders to avoid conflicts.

Fix #3807

Author: cmaglie

avr/platform.txt

@@ -65,18 +65,18 @@ recipe.S.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.S.flags} -mmcu={b
 recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{build.path}/{archive_file}" "{object_file}"
 
 ## Combine gc-sections, archives, and objects
-recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" {compiler.c.elf.flags} -mmcu={build.mcu} {compiler.c.elf.extra_flags} -o "{build.path}/sketch/{build.project_name}.elf" {object_files} "{build.path}/{archive_file}" "-L{build.path}" -lm
+recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" {compiler.c.elf.flags} -mmcu={build.mcu} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" {object_files} "{build.path}/{archive_file}" "-L{build.path}" -lm
 
 ## Create output files (.eep and .hex)
-recipe.objcopy.eep.pattern="{compiler.path}{compiler.objcopy.cmd}" {compiler.objcopy.eep.flags} {compiler.objcopy.eep.extra_flags} "{build.path}/sketch/{build.project_name}.elf" "{build.path}/sketch/{build.project_name}.eep"
-recipe.objcopy.hex.pattern="{compiler.path}{compiler.elf2hex.cmd}" {compiler.elf2hex.flags} {compiler.elf2hex.extra_flags} "{build.path}/sketch/{build.project_name}.elf" "{build.path}/sketch/{build.project_name}.hex"
+recipe.objcopy.eep.pattern="{compiler.path}{compiler.objcopy.cmd}" {compiler.objcopy.eep.flags} {compiler.objcopy.eep.extra_flags} "{build.path}/{build.project_name}.elf" "{build.path}/{build.project_name}.eep"
+recipe.objcopy.hex.pattern="{compiler.path}{compiler.elf2hex.cmd}" {compiler.elf2hex.flags} {compiler.elf2hex.extra_flags} "{build.path}/{build.project_name}.elf" "{build.path}/{build.project_name}.hex"
 
 ## Save hex
 recipe.output.tmp_file={build.project_name}.hex
 recipe.output.save_file={build.project_name}.{build.variant}.hex
 
 ## Compute size
-recipe.size.pattern="{compiler.path}{compiler.size.cmd}" -A "{build.path}/sketch/{build.project_name}.elf"
+recipe.size.pattern="{compiler.path}{compiler.size.cmd}" -A "{build.path}/{build.project_name}.elf"
 recipe.size.regex=^(?:\.text|\.data|\.bootloader)\s+([0-9]+).*
 recipe.size.regex.data=^(?:\.data|\.bss|\.noinit)\s+([0-9]+).*
 recipe.size.regex.eeprom=^(?:\.eeprom)\s+([0-9]+).*
@@ -97,11 +97,11 @@ tools.avrdude.config.path={path}/etc/avrdude.conf
 
 tools.avrdude.upload.params.verbose=-v
 tools.avrdude.upload.params.quiet=-q -q
-tools.avrdude.upload.pattern="{cmd.path}" "-C{config.path}" {upload.verbose} -p{build.mcu} -c{upload.protocol} -P{serial.port} -b{upload.speed} -D "-Uflash:w:{build.path}/sketch/{build.project_name}.hex:i"
+tools.avrdude.upload.pattern="{cmd.path}" "-C{config.path}" {upload.verbose} -p{build.mcu} -c{upload.protocol} -P{serial.port} -b{upload.speed} -D "-Uflash:w:{build.path}/{build.project_name}.hex:i"
 
 tools.avrdude.program.params.verbose=-v
 tools.avrdude.program.params.quiet=-q -q
-tools.avrdude.program.pattern="{cmd.path}" "-C{config.path}" {program.verbose} -p{build.mcu} -c{protocol} {program.extra_params} "-Uflash:w:{build.path}/sketch/{build.project_name}.hex:i"
+tools.avrdude.program.pattern="{cmd.path}" "-C{config.path}" {program.verbose} -p{build.mcu} -c{protocol} {program.extra_params} "-Uflash:w:{build.path}/{build.project_name}.hex:i"
 
 tools.avrdude.erase.params.verbose=-v
 tools.avrdude.erase.params.quiet=-q -q