Use custom GCC toolchain

Makefile

@@ -17,6 +17,18 @@ prepare:
 		cd limine; \
 		make; \
 	fi
+	if [ ! -d toolchain/binutils-gdb ]; then \
+		cd toolchain; \
+		git clone git://sourceware.org/git/binutils-gdb.git --depth=1; \
+		$(PWD)/scripts/build-binutils-gdb.sh; \
+		cd ..; \
+	fi
+	if [ ! -d toolchain/gcc ]; then \
+		cd toolchain; \
+		git clone https://gcc.gnu.org/git/gcc.git --depth=1; \
+		$(PWD)/scripts/build-gcc.sh; \
+		cd ..; \
+	fi
 
 cleanall:
 	make clean

mk/arch/toolchain-x86_64.mk

@@ -1,3 +1,5 @@
-CC := x86_64-elf-gcc
-LD := x86_64-elf-ld
-AR := x86_64-elf-ar
+PREFIX := $(ROOT)/toolchain/root/bin
+
+CC := $(PREFIX)/x86_64-elf-gcc
+LD := $(PREFIX)/x86_64-elf-ld
+AR := $(PREFIX)/x86_64-elf-ar

mk/user/x86_64.mk

@@ -9,4 +9,5 @@ CFLAGS += -m64 \
 					-fno-stack-protector \
 					-fno-stack-check \
 					-fno-builtin \
+					-fno-omit-frame-pointer \
 					-O0 \

scripts/build-binutils-gdb.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+PREFIX=$(pwd)/root
+
+mkdir build-bintuils-gdb
+cd build-bintuils-gdb
+../binutils-gdb/configure --prefix="$PREFIX" \
+                          --disable-nls \
+                          --disable-werror \
+                          --target=x86_64-elf
+make -j$(nproc)
+make install

scripts/build-gcc.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+PREFIX=$(pwd)/root
+
+cd gcc
+./contrib/download_prerequisites
+cd ..
+mkdir build-gcc
+cd build-gcc
+../gcc/configure --prefix="$PREFIX" \
+                 --disable-nls \
+                 --enable-languages=c \
+                 --target=x86_64-elf \
+                 --disable-bootstrap \
+                 --without-headers \
+                 --disable-shared \
+                 --disable-threads \
+                 --disable-libssp \
+                 --disable-libquadmath \
+                 --disable-libgomp \
+                 --disable-libatomic \
+                 --disable-libmudflap \
+                 --disable-multilib
+make -j$(nproc)
+make install