Implement syscalls, hello world from userspace

2025-09-02 23:51:14 +02:00
parent 920de10025
commit 8a12f23b69
24 changed files with 313 additions and 44 deletions
--- a/user/arch/x86_64/link.ld
+++ b/user/arch/x86_64/link.ld
@ -1,7 +1,6 @@
 ENTRY(_start)

 SECTIONS {
-  /* . = 0xffff000000000000; */
  . = 0x0000000000000000;

  .rodata ALIGN(4K):
--- a/user/hello/Makefile
+++ b/user/hello/Makefile
@ -16,7 +16,7 @@ all: $(TARGET)

 hello: $(OBJ)
 	$(LD) $^ $(LDFLAGS) -o $@
-	echo $(realpath $@) >> $(FILES)
+	echo $(realpath hello) >> $(FILES)

 clean:
 	rm -f $(OBJ) $(TARGET)
--- a/user/hello/hello.s
+++ b/user/hello/hello.s
@ -1,6 +1,18 @@
+.section .data
+STRING:
+  .string "Hello World from userspace"
+STRING_LEN:
+  .quad . - STRING
+
+.section .text

 .global _start
 _start:
-.spin:
-  jmp .spin
+  movq $1, %rax
+  lea STRING(%rip), %rdi
+  lea STRING_LEN(%rip), %rsi
+  syscall
+
+  movq $2, %rax
+  syscall