6 files changed, 27 insertions, 10 deletions

@@ -6,16 +6,18 @@ bin_ln="bin"
 
 netbsd_note_src="$src/netbsd-note.s"
 netbsd_note_bin="$out/netbsd-note.o"
-start_src="$src/start.s"
-start_bin="$out/start.o"
+netbsd_start_src="$src/netbsd-start.s"
+netbsd_start_bin="$out/netbsd-start.o"
+linux_start_src="$src/linux-start.s"
+linux_start_bin="$src/linux-start.o"
 main_src="$src/main.c"
 main_bin="$out/main.o"
 
 ln="ln"
 as="as"
 ld="ld"
-ld_netbsd_cfg="netbsd-cfg.ld"
-ld_linux_cfg="linux-cfg.ld"
+netbsd_ld_cfg="netbsd-cfg.ld"
+linux_ld_cfg="linux-cfg.ld"
 cc="gcc"
 
 lnflgs="-sf"
@@ -2,7 +2,7 @@
 set -e
 
 mkdir $out
-$as $asflgs -o $start_bin $start_src
+$as $asflgs -o $linux_start_bin $linux_start_src
 $cc $ccflgs -o $main_bin -c $main_src
-$ld $ldflgs -T $ld_linux_cfg -o $bin $start_bin $main_bin
+$ld $ldflgs -T $linux_ld_cfg -o $bin $linux_start_bin $main_bin
 $ln $lnflgs $bin $bin_ln
@@ -3,7 +3,7 @@ set -e
 
 mkdir $out
 $as $asflgs -o $netbsd_note_bin $netbsd_note_src
-$as $asflgs -o $start_bin $start_src
+$as $asflgs -o $netbsd_start_bin $netbsd_start_src
 $cc $ccflgs -o $main_bin -c $main_src
-$ld $ldflgs -T $ld_netbsd_cfg -o $bin $netbsd_note_bin $start_bin $main_bin
+$ld $ldflgs -T $netbsd_ld_cfg -o $bin $netbsd_note_bin $netbsd_start_bin $main_bin
 $ln $lnflgs $bin $bin_ln
@@ -0,0 +1,16 @@
+.section .text
+.globl _start
+.type _start, @function
+_start:
+        xorq %rbp, %rbp # frame ptr (%rbp) = null. marks stack bottom.
+
+        movq (%rsp), %rdi # argc = first 4 bytes of stack.
+        leaq 8(%rsp), %rsi # argv = address of first arg ptr.
+
+        call main
+
+        movl %eax, %edi # status = ret val.
+        movl $60, %eax # SYS_exit = 60.
+        syscall
+
+        hlt # if syscall fails hang.
@@ -4,7 +4,7 @@
 _start:
         xorq %rbp, %rbp # frame ptr (%rbp) = null. marks stack bottom.
 
-        movl (%rsp), %edi # argc = first 4 bytes of stack.
+        movq (%rsp), %rdi # argc = first 4 bytes of stack.
         leaq 8(%rsp), %rsi # argv = address of first arg ptr.
 
         call main
@@ -13,5 +13,4 @@ _start:
         movl $1, %eax # SYS_exit = 1.
         syscall
 
-        .size _start, .-_start
         hlt # if syscall fails hang.