Hello user process

user/.gitignore

@@ -0,0 +1 @@
+FILES.txt

user/Makefile

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+CURRENT_DIR := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
+
+.PHONY: all clean
+
+APP_DIR := $(shell find . -mindepth 1 -maxdepth 1 -type d -not -path "./arch")
+
+all:
+	rm -f FILES.txt
+	touch FILES.txt
+	for dir in $(APP_DIR); do make -C $$dir FILES=$(CURRENT_DIR)/FILES.txt all; done
+
+clean:
+	for dir in $(APP_DIR); do make -C $$dir clean; done
+

user/Makefile.inc

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+ARCH ?= x86_64
+
+CFLAGS := -ffreestanding -Wall -Wextra -g -fcommon -nostdinc
+
+CURRENT_DIR := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
+
+include $(CURRENT_DIR)/arch/$(ARCH)/$(ARCH).mk
+
+LDFLAGS += -nostdlib -static $(shell $(CC) -print-libgcc-file-name) -T $(CURRENT_DIR)/arch/$(ARCH)/link.ld

user/arch/x86_64/link.ld

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+ENTRY(_start)
+
+SECTIONS {
+  /* . = 0xffff000000000000; */
+  . = 0x0000000000000000;
+
+  .rodata ALIGN(4K):
+  {
+    *(.rodata .rodata.*)
+  }
+
+  .text ALIGN(4K):
+  {
+    *(.text .text.*)
+  }
+
+  .data ALIGN(4K):
+  {
+    *(.data .data.*)
+  }
+
+  .bss ALIGN(4K):
+  {
+    *(.bss .bss.*)
+  }
+}

user/arch/x86_64/x86_64.mk

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+CC := x86_64-elf-gcc
+LD := x86_64-elf-ld
+
+CFLAGS += -m64 \
+					-fPIE \
+					-mno-80387 \
+					-mno-mmx \
+					-mno-sse \
+					-nostartfiles \
+					-nostdlib \
+					-mno-sse2 \
+					-mno-red-zone \
+					-fno-stack-protector \
+					-fno-stack-check \
+					-Os \
+
+LDFLAGS += -m elf_x86_64 \
+					-pie \
+					--no-dynamic-linker \
+					-z text \
+					-z max-page-size=0x1000
+

user/hello/.gitignore

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+*.o
+hello

user/hello/Makefile

@@ -0,0 +1,21 @@
+include ../Makefile.inc
+
+.PHONY: all clean
+
+TARGET := hello
+
+SRCFILES := $(wildcard *.s)
+ASFILES := $(filter %.s,$(SRCFILES))
+OBJ := $(patsubst %.s,%.o,$(ASFILES))
+
+%.o: %.s
+	$(CC) $(CFLAGS) -c $< -o $@
+
+all: $(TARGET)
+
+hello: $(OBJ)
+	$(LD) $^ $(LDFLAGS) -o $@
+	echo "$(realpath $@)" >> $(FILES)
+
+clean:
+	rm -f $(OBJ) $(TARGET)

user/hello/hello.s

@@ -0,0 +1,6 @@
+
+.global _start
+_start:
+.spin:
+  jmp .spin
+