Added build system and some core boot files

.gitignore

@@ -1,50 +1,59 @@
-# Created by https://www.gitignore.io/api/c++,vim,linux,cmake,windows
+# Created by https://www.toptal.com/developers/gitignore/api/vim,macos,windows,linux,rust,c
+# Edit at https://www.toptal.com/developers/gitignore?templates=vim,macos,windows,linux,rust,c
 
-### C++ ###
+### C ###
 # Prerequisites
 *.d
 
-# Compiled Object files
+# Object files
-*.slo
-*.lo
 *.o
+*.ko
 *.obj
+*.elf
+
+# Linker output
+*.ilk
+*.map
+*.exp
 
 # Precompiled Headers
 *.gch
 *.pch
 
-# Compiled Dynamic libraries
+# Libraries
-*.so
-*.dylib
-*.dll
-
-# Fortran module files
-*.mod
-*.smod
-
-# Compiled Static libraries
-*.lai
-*.la
-*.a
 *.lib
+*.a
+*.la
+*.lo
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
 
 # Executables
 *.exe
 *.out
 *.app
+*.i*86
+*.x86_64
+*.hex
 
-### CMake ###
+# Debug files
-CMakeCache.txt
+*.dSYM/
-CMakeFiles
+*.su
-CMakeScripts
+*.idb
-Testing
+*.pdb
-Makefile
+
-cmake_install.cmake
+# Kernel Module Compile Results
-install_manifest.txt
+*.mod*
-compile_commands.json
+*.cmd
-CTestTestfile.cmake
+.tmp_versions/
-build
+modules.order
+Module.symvers
+Mkfile.old
+dkms.conf
 
 ### Linux ###
 *~
@@ -61,25 +70,86 @@ build
 # .nfs files are created when an open file is removed but is still being accessed
 .nfs*
 
+### macOS ###
+# General
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+### macOS Patch ###
+# iCloud generated files
+*.icloud
+
+### Rust ###
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+
 ### Vim ###
-# swap
+# Swap
-.sw[a-p]
+[._]*.s[a-v][a-z]
-.*.sw[a-p]
+!*.svg  # comment out if you don't need vector files
-# session
+[._]*.sw[a-p]
+[._]s[a-rt-v][a-z]
+[._]ss[a-gi-z]
+[._]sw[a-p]
+
+# Session
 Session.vim
-# temporary
+Sessionx.vim
+
+# Temporary
 .netrwhist
-# auto-generated tag files
+# Auto-generated tag files
 tags
+# Persistent undo
+[._]*.un~
 
 ### Windows ###
 # Windows thumbnail cache files
 Thumbs.db
+Thumbs.db:encryptable
 ehthumbs.db
 ehthumbs_vista.db
 
+# Dump file
+*.stackdump
+
 # Folder config file
-Desktop.ini
+[Dd]esktop.ini
 
 # Recycle Bin used on file shares
 $RECYCLE.BIN/
@@ -87,15 +157,14 @@ $RECYCLE.BIN/
 # Windows Installer files
 *.cab
 *.msi
+*.msix
 *.msm
 *.msp
 
 # Windows shortcuts
 *.lnk
 
+# End of https://www.toptal.com/developers/gitignore/api/vim,macos,windows,linux,rust,c
 
-# End of https://www.gitignore.io/api/c++,vim,linux,cmake,windows
+build
-
-.DS_Store
 .clang-format
-.ccls-cache

Makefile

@@ -0,0 +1,44 @@
+KERNEL_EXEC := socks_kernel
+
+ARCH := x86_64
+
+include tools/make/gcc-cross-compile.mk
+include arch/$(ARCH)/config.mk
+
+BUILDDIR := build
+
+ARCH_C_FILES := $(wildcard arch/$(ARCH)/*.c)
+ARCH_ASM_FILES := $(wildcard arch/$(ARCH)/*.S)
+ARCH_OBJ := $(addprefix $(BUILDDIR)/,$(ARCH_C_FILES:.c=.o) $(ARCH_ASM_FILES:.S=.o))
+
+SRC_DIRS := core
+KERNEL_C_FILES := $(foreach dir,$(SRC_DIRS),$(wildcard $(dir)/*.c))
+KERNEL_OBJ := $(addprefix $(BUILDDIR)/,$(KERNEL_C_FILES:.c=.o))
+
+$(BUILDDIR)/$(KERNEL_EXEC): $(KERNEL_OBJ) $(ARCH_OBJ)
+	@echo "    \033[1;36mLINK\033[0m   \033[1m$@\033[0m"
+	@mkdir -p $(@D)
+	@$(LD) $^ -o $@ $(LDFLAGS) $(ARCH_LDFLAGS)
+
+$(BUILDDIR)/%.o: %.S
+	@echo "    \033[1;32mASM\033[0m    $<"
+	@mkdir -p $(@D)
+	@$(ASM) $< -o $@ -c $(ASMFLAGS) $(ARCH_ASMFLAGS)
+
+$(BUILDDIR)/%.o: %.c
+	@echo "    \033[1;32mCC\033[0m     $<"
+	@mkdir -p $(@D)
+	@$(CC) $< -o $@ -c $(CFLAGS) $(ARCH_CFLAGS)
+
+clean:
+	@echo "    \033[1;93mCLEAN\033[0m  Deleting build artefacts."
+	@rm -rf $(BUILDDIR)
+
+
+all: $(BUILDDIR)/$(KERNEL_EXEC)
+
+include arch/$(ARCH)/extra.mk
+
+.PHONY: all
+
+.INTERMEDIATE: $(ARCH_TEMP_FILES)

arch/x86_64/config.mk

@@ -0,0 +1,2 @@
+ARCH_CFLAGS := -z max-page-size=0x1000 -m64 -mcmodel=large -mno-red-zone -mno-mmx -mno-sse -mno-sse2 -D_64BIT -DBYTE_ORDER=1234
+ARCH_LDFLAGS := -z max-page-size=0x1000 -T arch/x86_64/layout.ld

arch/x86_64/extra.mk

@@ -0,0 +1,21 @@
+QEMU := qemu-system-x86_64
+
+ARCH_TEMP_FILES := $(BUILDDIR)/$(KERNEL_EXEC).elf32
+
+# qemu refuses to boot ELF64 binaries. this creates a patched version of the kernel
+# binary to trick qemu into thinking its an ELF32.
+# this has no effect on the kernel itself; the x86_64 kernel's
+# entry point is 32-bit machine code.
+$(BUILDDIR)/$(KERNEL_EXEC).elf32: $(BUILDDIR)/$(KERNEL_EXEC)
+	@cp $(BUILDDIR)/$(KERNEL_EXEC) $(BUILDDIR)/$(KERNEL_EXEC).elf32
+	@printf '\x03\x00' | dd of=$(BUILDDIR)/$(KERNEL_EXEC).elf32 bs=1 seek=18 count=2 conv=notrunc 2> /dev/null
+
+run: $(BUILDDIR)/$(KERNEL_EXEC) $(BUILDDIR)/$(KERNEL_EXEC).elf32
+	@echo "    \033[1;93mBOOT\033[0m   $<"
+
+	@$(QEMU) -kernel $(BUILDDIR)/$(KERNEL_EXEC).elf32
+
+debug: $(BUILDDIR)/$(KERNEL_EXEC) $(BUILDDIR)/$(KERNEL_EXEC).elf32
+	@echo "    \033[1;93mBOOT\033[0m   $<"
+
+	@$(QEMU) -kernel $(BUILDDIR)/$(KERNEL_EXEC).elf32 -S -s

arch/x86_64/layout.ld

@@ -0,0 +1,56 @@
+ENTRY(_start)
+
+KERNEL_LMA = 1M;
+KERNEL_VMA = 0xFFFFFFFF80000000;
+
+SECTIONS {
+	. = KERNEL_LMA;
+
+	.boot.text ALIGN(4K) : {
+		*(.boot.text)
+		*(.boot.rodata)
+	}
+
+	.boot.bss ALIGN(4K) : {
+		*(.boot.bss)
+	}
+
+    . += KERNEL_VMA;
+
+    .text ALIGN(4K) : AT(ADDR(.text) - KERNEL_VMA)
+    {
+        *(.text)
+    }
+
+   .data ALIGN(4K) : AT(ADDR(.data) - KERNEL_VMA)
+   {
+        _data = .;
+        *(.data)
+   }
+
+   .eh_frame ALIGN(4K) : AT(ADDR(.eh_frame) - KERNEL_VMA)
+   {
+       _ehframe = .;
+       *(.eh_frame)
+   }
+
+   .bss ALIGN(4K) : AT(ADDR(.bss) - KERNEL_VMA)
+   {
+       _bss = .;
+       *(.bss)
+
+	   */
+       /*
+        * You usually need to include generated COMMON symbols
+        * under kernel BSS section or use gcc's -fno-common
+        */
+        *(COMMON)
+   }
+
+   _end = .;
+
+   /DISCARD/ :
+   {
+        *(.comment)
+   }
+}

arch/x86_64/start_32.S

@@ -0,0 +1,213 @@
+.set ALIGN,		   1 << 0
+.set MEMINFO,	   1 << 1
+.set VIDMODE,	   1 << 2
+.set FLAGS,		   ALIGN | MEMINFO
+.set MAGIC,		   0x1BADB002
+.set CHECKSUM,	   -(MAGIC + FLAGS)
+
+/* the amount of memory to allocate for bootstrap page directories. */
+#define BOOTSTRAP_PDIR_SIZE 0x1000
+
+.extern start_64	# defined in start_64.S
+
+.code32
+
+.section .boot.rodata, "a", @progbits
+no_long_mode_err:
+    .asciz "This system is not 64-bit. Press any key to reboot."
+
+unsupported_cpu_err:
+    .asciz "Your CPU is not supported by Magenta. Press any key to reboot."
+
+.section .boot.bss, "aw", @nobits
+bootstrap_pml4t:		# a single PML4T
+	.skip 0x1000
+bootstrap_pdpt:		# a single PDPT
+	.skip 0x1000
+bootstrap_pdir_buf:	# a buffer of page directories. each pdir entry can be used to map 2MB of virtual memory.
+	.skip BOOTSTRAP_PDIR_SIZE
+bootstrap_stack_bottom:
+	.skip 0x1000
+bootstrap_stack_top:
+
+.section .boot.text, "ax", @progbits
+.align 4
+.long MAGIC
+.long FLAGS
+.long CHECKSUM
+
+# Print an error message and wait for RETURN if the system's CPU doesn't support long mode.
+no_long_mode:
+	# print error message
+	mov $no_long_mode_err, %esi
+
+	mov $0xb8000, %edi
+1:
+	movsb
+	movb $12, (%edi)
+	incl %edi
+	cmpb $0, (%esi)
+	jne 1b
+
+2:
+	inb $0x64, %al
+	test $0x01, %al
+	jz 3f
+	inb $0x60, %al
+	jmp 2b
+
+3:
+	inb $0x64, %al
+	test $0x01, %al
+	jz 3b
+
+	int $0xff
+	cli
+	hlt
+
+# Print an error message and wait for RETURN if the system's CPU isn't supported.
+unsupported_cpu:
+	# print error message
+	mov $unsupported_cpu_err, %esi
+
+	mov $0xb8000, %edi
+1:
+	movsb
+	movb $12, (%edi)
+	incl %edi
+	cmpb $0, (%esi)
+	jne 1b
+
+2:
+	inb $0x64, %al
+	test $0x01, %al
+	jz 3f
+	inb $0x60, %al
+	jmp 2b
+
+3:
+	inb $0x64, %al
+	test $0x01, %al
+	jz 3b
+
+	int $0xff
+	cli
+	hlt
+
+init_page_tables:
+	/* STEP 1: add an entry in the PML4T pointing to the PDPT.
+	   NOTE that we actually add two entries in the PML4T that both point to the same PDPT.
+	   This allows us to map the kernel at both vaddr 0x0 AND vaddr 0xffffffff80000000 using the same PDPT */
+
+	mov $bootstrap_pml4t, %edi
+	mov $bootstrap_pdpt, %esi
+
+	# in %ESI, build a PML4T entry containing the base address of the PDPT
+	xor $0xFFF, %esi
+	or $0x3, %esi
+
+	# add the PML4T entries at PML4T[0] and PML4T[511]
+	mov %esi, (%edi)
+	add $0xFF8, %edi
+	mov %esi, (%edi)
+
+	/* STEP 2: initialise the PDPT.
+	   We need to create an entry in the PDPT for every page directory we intend to use. */
+
+	# BOOTSTRAP_PDIR_SIZE contains the total size of the page directory buffer.
+	# use it to calculate the number of page directories we're using.
+	mov $0, %edx
+	mov $BOOTSTRAP_PDIR_SIZE, %eax
+	mov $0x1000, %ebx
+	idiv %ebx
+
+	mov $bootstrap_pdpt, %edi
+	mov $bootstrap_pdir_buf, %esi
+	/* %ESI is a pointer into the pagedir buffer.
+	   %EDI is a pointer into the PDPT.
+	   %EAX is the total number of page directories.
+	   %EBX is where we build the PDPT entry. */
+1:
+	mov %esi, %ebx
+	xor $0xFFF, %ebx
+	or $0x3, %ebx
+
+	# skip the first 4 bytes of the 8-byte entry, leaving them zero.
+	add $0x4, %edi
+	mov %ebx, (%edi)
+
+	add $0x1000, %esi
+	add $0x4, %edi
+	sub $0x1, %eax
+
+	cmp $0x0, %eax
+	jne 1b
+
+	/* STEP 3: initialise the page directories.
+	   Each page directory can be used to map 2MiB of virtual memory.
+	   The exact number of page directories in use is determined by BOOTSTRAP_PDIR_SIZE */
+
+	/* the total number of page directory entries is stored in %EAX */
+	mov $0, %edx
+	mov $BOOTSTRAP_PDIR_SIZE, %eax
+	mov $0x8, %ebx
+	idiv %ebx
+
+	mov $0x0, %esi
+	mov $bootstrap_pdir_buf, %edi
+	/* %EDI is a pointer into the pagedir buffer.
+	   %ESI is the physical address being mapped. must be a multiple of 2MiB.
+	   %EAX is the total number of page directories.
+	   %EBX is where we build the pagedir entry. */
+
+2:
+	mov %esi, %ebx
+	xor $0xFFF, %ebx
+	or $0x3, %ebx
+
+	# skip the first 4 bytes of the 8-byte entry, leaving them zero.
+	add $0x4, %edi
+	mov %ebx, (%edi)
+
+	add $0x200000, %esi
+	add $0x4, %edi
+	dec %eax
+	jnz 2b
+
+	ret
+
+long_mode_switch:
+	ret
+
+.global _start
+.type _start, @function
+
+_start:
+	mov $bootstrap_stack_top, %esp
+
+	push %ebx								# store the pointer to the multiboot info block.
+
+	# check if long mode is supported
+	movl $0x80000000, %eax					# Extended-function 80000000h.
+	cpuid									# Is largest extended function
+	cmpl $0x80000000, %eax					# any function > 80000000h?
+	jbe no_long_mode						# If not, no long mode.
+	movl $0x80000001, %eax					# Extended-function 80000001h.
+	cpuid									# Now EDX = extended-features flags.
+	btl $29, %edx							# Test if long mode is supported.
+	jnc no_long_mode						# Exit if not supported.
+
+	movl $1, %eax
+	cpuid
+	btl $3, %edx
+
+	mov $0xb8000, %eax
+	movb $76, (%eax)
+	inc %eax
+	movb $0xF, (%eax)
+
+	call init_page_tables
+	call long_mode_switch					# calls start_64, does not return
+
+	cli
+	hlt

arch/x86_64/start_64.S

@@ -0,0 +1,10 @@
+.section .boot.text, "ax", @progbits
+
+.code64
+.global start_64
+.type start_64, @function
+start_64:
+	mov $0xb8000, %rax
+	movb $77, (%rax)
+	inc %rax
+	movb $0xF, (%rax)

core/main.c

@@ -0,0 +1,4 @@
+void kernel_init()
+{
+
+}

tools/make/clang-generic.mk

@@ -0,0 +1,5 @@
+LD := ld.lld
+CC := clang
+
+CFLAGS := -fuse-ld=$(LD) -target x86_64-linux-elf -nostdlib -nostdinc -ffreestanding -Wl,-nostdlib -Wno-unused-command-line-argument
+LDFLAGS := -nostdlib

tools/make/gcc-cross-compile.mk

@@ -0,0 +1,8 @@
+LD  := $(ARCH)-elf-gcc
+CC  := $(ARCH)-elf-gcc
+ASM := $(ARCH)-elf-gcc
+
+CFLAGS   := -nostdlib -nostdinc -ffreestanding -Wl,-nostdlib
+ASMFLAGS := $(CFLAGS)
+LDFLAGS  := -nostdlib
+