linker could not found object files from different directory with scons - compilation

Question

Currently, I make a project with scons.
I compiled source codes and it is time to link them.
However, I got an error that ld cannot find object files.
The SConscript is located in src/kernel32, and
import os, sys
# Compile CPP
env_gpp_options = {
'CXX' : 'x86_64-pc-linux-g++',
'CXXFLAGS' : '-std=c++11 -g -m32 -ffreestanding -fno-exceptions -fno-rtti',
'LINK' : 'x86_64-pc-linux-ld',
'LINKFLAGS' : '-melf_i386 -T scripts/elf_i386.x -nostdlib -e main -Ttext 0x10200',
}
env_gpp = Environment(**env_gpp_options)
env_gpp.Append(ENV = {'PATH' : os.environ['PATH']})
object_cpp_list = Glob('*.cpp')
for object_cpp in object_cpp_list:
env_gpp.Object(object_cpp)
# Find all object file
object_target_list = Glob('*.o')
# Linking
env_link_target = 'kernel32.elf'
env_gpp.Program(env_link_target, object_target_list)
and message I got is
x86_64-pc-linux-g++ -o build/kernel32/cpu.o -c -std=c++11 -g -m32 -ffreestanding -fno-exceptions -fno-rtti src/kernel32/cpu.cpp
x86_64-pc-linux-g++ -o build/kernel32/main.o -c -std=c++11 -g -m32 -ffreestanding -fno-exceptions -fno-rtti src/kernel32/main.cpp
x86_64-pc-linux-g++ -o build/kernel32/memory.o -c -std=c++11 -g -m32 -ffreestanding -fno-exceptions -fno-rtti src/kernel32/memory.cpp
x86_64-pc-linux-g++ -o build/kernel32/pageManager.o -c -std=c++11 -g -m32 -ffreestanding -fno-exceptions -fno-rtti src/kernel32/pageManager.cpp
x86_64-pc-linux-g++ -o build/kernel32/utils.o -c -std=c++11 -g -m32 -ffreestanding -fno-exceptions -fno-rtti src/kernel32/utils.cpp
x86_64-pc-linux-ld -o build/kernel32/kernel32.elf -melf_i386 -T scripts/elf_i386.x -nostdlib -e main -Ttext 0x10200 build/kernel32/asmUtils.o build/kernel32/cpu.o build/kernel32/main.o build/kernel32/memory.o build/kernel32/pageManager.o build/kernel32/utils.o
x86_64-pc-linux-ld: cannot find main.o
scons: *** [build/kernel32/kernel32.elf] Error 1
scons: building terminated because of errors.
I checked the directory, build/kernel32/, and I found main.o file.
What is my mistake?
Is there an way to change working directory for scons?
Please let me know what I missed.

Answer 1

You can try this:
import os, sys
# Compile CPP
env_gpp_options = {
'CXX' : 'x86_64-pc-linux-g++',
'CXXFLAGS' : '-std=c++11 -g -m32 -ffreestanding -fno-exceptions -fno-rtti',
'LINK' : 'x86_64-pc-linux-ld',
'LINKFLAGS' : '-melf_i386 -T scripts/elf_i386.x -nostdlib -e main -Ttext 0x10200',
}
env_gpp = Environment(**env_gpp_options)
env_gpp.Append(ENV = {'PATH' : os.environ['PATH']})
object_cpp_list = Glob('*.cpp')
object_target_list = []
for object_cpp in object_cpp_list:
object_target_list.extend(env_gpp.Object(object_cpp))
# Linking
env_link_target = 'kernel32.elf'
env_gpp.Program(env_link_target, object_target_list)
Or
import os, sys
# Compile CPP
env_gpp_options = {
'CXX' : 'x86_64-pc-linux-g++',
'CXXFLAGS' : '-std=c++11 -g -m32 -ffreestanding -fno-exceptions -fno-rtti',
'LINK' : 'x86_64-pc-linux-ld',
'LINKFLAGS' : '-melf_i386 -T scripts/elf_i386.x -nostdlib -e main -Ttext 0x10200',
}
env_gpp = Environment(**env_gpp_options)
env_gpp.Append(ENV = {'PATH' : os.environ['PATH']})
object_cpp_list = Glob('*.cpp')
# Linking
env_link_target = 'kernel32.elf'
env_gpp.Program(env_link_target, object_cpp_list)

Answer 2

This is full scons scripts.
In project root directory,
#SConstruct
build_dir = 'build'
# Build
SConscript(['src/SConscript'], variant_dir = build_dir, duplicate = 0)
# Clean
Clean('.', build_dir)
In src directory
#SConscript for src
SConscript(['bootloader/SConscript',
'kernel32/SConscript'])
In kernel32 directory
#SConscript for kernel32
import os, sys
# Build entry
env_entry = Environment(tools=['default', 'nasm'])
target_entry = 'entry.bin'
object_entry = 'entry.s'
output_entry = env_entry.Object(target_entry, object_entry)
# Compile CPP
env_gpp_options = {
'CXX' : 'x86_64-pc-linux-g++',
'CXXFLAGS' : '-std=c++11 -g -m32 -ffreestanding -fno-exceptions -fno-rtti',
'LINK' : 'x86_64-pc-linux-ld',
'LINKFLAGS' : '-melf_i386 -T scripts/elf_i386.x -nostdlib -e main -Ttext 0x10200',
}
env_gpp = Environment(**env_gpp_options)
env_gpp.Append(ENV = {'PATH' : os.environ['PATH']})
object_cpp_list = Glob('*.cpp')
for object_cpp in object_cpp_list:
env_gpp.Object(object_cpp)
# Compile ASM
env_nasm = Environment(tools=['default', 'nasm'])
env_nasm.Append(ASFLAGS='-f elf32')
object_nasm_list = Glob('*.asm')
for object_nasm in object_nasm_list:
env_nasm.Object(object_nasm)
# Find all object file
object_target_list = Glob('*.o')
object_target_list.append('entry.bin')
# Linking
env_link_target = 'kernel32.elf'
env_gpp.Program(env_link_target, object_target_list)
Thank you for your attention.