diff options
| -rw-r--r-- | .gitignore | 4 | ||||
| -rw-r--r-- | Makefile | 15 | ||||
| -rw-r--r-- | main.s | 10 | ||||
| -rw-r--r-- | sys.s | 69 | ||||
| -rw-r--r-- | syscall.awk | 12 |
5 files changed, 110 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..68db9ac --- /dev/null +++ b/.gitignore @@ -0,0 +1,4 @@ +syscall.s +hello +*.o +*~ diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..69beadf --- /dev/null +++ b/Makefile @@ -0,0 +1,15 @@ +PROGNAME=$(shell pwd | xargs basename) + +$(PROGNAME): main.o + ld -o $@ $< + +%.o: %.s syscall.s + as -o $@ $< + +syscall.s: /usr/include/asm/unistd_64.h + @echo create $@ from $< + @awk -f syscall.awk $< > $@ + +clean: + @echo cleaning... + @rm -f syscall.s *~ *.o core* @@ -0,0 +1,10 @@ +.include "sys.s" + +.globl _start +_start: + sys write, $STDOUT, $msg, $len + sys exit, $0 + +.data +msg: .ascii "Hello, World!\n" +len = .-msg @@ -0,0 +1,69 @@ +.ifndef __SYS__ +.set __SYS__, 1 + +.include "syscall.s" + +# sys call args: +# %rdi +# %rsi +# %rdx +# %rcx +# %r8 +# %r9 + +.macro __putargs6 arg:req, args:vararg + movq \arg, %r9 +.endm + +.macro __putargs5 arg:req, args:vararg + movq \arg, %r8 +.ifnb \args + __putargs6 \args +.endif +.endm + +.macro __putargs4 arg:req, args:vararg + movq \arg, %rcx +.ifnb \args + __putargs5 \args +.endif +.endm + +.macro __putargs3 arg:req, args:vararg + movq \arg, %rdx +.ifnb \args + __putargs4 \args +.endif +.endm + +.macro __putargs2 arg:req, args:vararg + movq \arg, %rsi +.ifnb \args + __putargs3 \args +.endif +.endm + +.macro __putargs1 arg:req, args:vararg + movq \arg, %rdi +.ifnb \args + __putargs2 \args +.endif +.endm + +.macro sysargs args:vararg +.ifnb \args + __putargs1 \args +.endif +.endm + +.macro sys func:req, args:vararg + sysargs \args + movq $__NR_\func, %rax + syscall +.endm + +.set STDIN, 0 +.set STDOUT, 1 +.set STDERR, 2 + +.endif diff --git a/syscall.awk b/syscall.awk new file mode 100644 index 0000000..521fee8 --- /dev/null +++ b/syscall.awk @@ -0,0 +1,12 @@ +BEGIN { + print ".ifndef __SYSCALL__" + print ".set __SYSCALL__, 1" + print "" +} + +/#define __NR_/ { printf ".equ %s, %s\n", $2, $3 } + +END { + print "" + print ".endif" +} |