From 828dd435725ea315abd2ea9875325ee3b17041a9 Mon Sep 17 00:00:00 2001
From: "Nathan P. Reiner" <nathan@nathanreiner.xyz>
Date: Thu, 15 Dec 2022 18:20:33 +0100
Subject: did this while lecture (builtins, parsing, exec and env by stdlib)

---
 lib/cstr/cstr.c  | 4 ++--
 lib/sys/brk.h    | 3 ++-
 lib/sys/close.h  | 2 +-
 lib/sys/dup2.h   | 2 +-
 lib/sys/execve.h | 2 +-
 lib/sys/exit.h   | 2 +-
 lib/sys/fork.h   | 3 ++-
 lib/sys/mmap.h   | 3 ++-
 lib/sys/munmap.h | 3 ++-
 lib/sys/pipe.h   | 2 +-
 lib/sys/read.h   | 3 ++-
 lib/sys/reboot.h | 3 ++-
 lib/sys/sbrk.h   | 3 ++-
 lib/sys/start.S  | 6 +++++-
 lib/sys/stat.h   | 3 ++-
 lib/sys/write.h  | 3 ++-
 16 files changed, 30 insertions(+), 17 deletions(-)

(limited to 'lib')

diff --git a/lib/cstr/cstr.c b/lib/cstr/cstr.c
index fcb91f4..f464cf3 100644
--- a/lib/cstr/cstr.c
+++ b/lib/cstr/cstr.c
@@ -264,7 +264,7 @@ u8 previous_utf8(const char **c)
 void u64_to_cstr(u64 n, char *cstr, u64 length)
 {
 	char *p = cstr + length - 1;
-	u64 d;
+	u64 d = 0;
 	int i = 0;
 
 	for (;n && i < length; ++i) {
@@ -272,7 +272,7 @@ void u64_to_cstr(u64 n, char *cstr, u64 length)
 		n /= 10;
 	}
 
-	d = p - cstr;
+	d = p - cstr + 1;
 
 	for (i = 0; i < length - d; ++i)
 		cstr[i] = cstr[i + d];
diff --git a/lib/sys/brk.h b/lib/sys/brk.h
index d2221a2..72f1edd 100644
--- a/lib/sys/brk.h
+++ b/lib/sys/brk.h
@@ -3,7 +3,8 @@
 
 #include "syscalls.h"
 
-static unsigned long brk(void * addr) {
+static unsigned long brk(void * addr)
+{
 	return syscall(BRK, addr);
 }
 
diff --git a/lib/sys/close.h b/lib/sys/close.h
index 2aa3a71..5a6fbe4 100644
--- a/lib/sys/close.h
+++ b/lib/sys/close.h
@@ -3,7 +3,7 @@
 
 #include "syscalls.h"
 
-int close(unsigned int fd)
+static int close(unsigned int fd)
 {
 	syscall(CLOSE, fd);
 }
diff --git a/lib/sys/dup2.h b/lib/sys/dup2.h
index 7726efb..9e67eec 100644
--- a/lib/sys/dup2.h
+++ b/lib/sys/dup2.h
@@ -3,7 +3,7 @@
 
 #include "syscalls.h"
 
-int dup2(unsigned int oldfd, unsigned int newfd)
+static int dup2(unsigned int oldfd, unsigned int newfd)
 {
 	return syscall(DUP2, oldfd, newfd);
 }
diff --git a/lib/sys/execve.h b/lib/sys/execve.h
index 04d6dea..62ebefc 100644
--- a/lib/sys/execve.h
+++ b/lib/sys/execve.h
@@ -3,7 +3,7 @@
 
 #include "syscalls.h"
 
-int execve(const char *pathname, char *const argv[], char *const envp[])
+static int execve(const char *pathname, char *const argv[], char *const envp[])
 {
 	return syscall(EXECVE, pathname, argv, envp);
 }
diff --git a/lib/sys/exit.h b/lib/sys/exit.h
index 516d714..0063a13 100644
--- a/lib/sys/exit.h
+++ b/lib/sys/exit.h
@@ -3,7 +3,7 @@
 
 #include "syscalls.h"
 
-_Noreturn void exit(int error_code)
+static void exit(int error_code)
 {
 	syscall(EXIT, error_code);
 }
diff --git a/lib/sys/fork.h b/lib/sys/fork.h
index 2ee3ae8..2a8adbf 100644
--- a/lib/sys/fork.h
+++ b/lib/sys/fork.h
@@ -3,7 +3,8 @@
 
 #include "syscalls.h"
 
-int fork() {
+static int fork()
+{
 	return syscall(FORK);
 }
 
diff --git a/lib/sys/mmap.h b/lib/sys/mmap.h
index 7e885c4..d555e68 100644
--- a/lib/sys/mmap.h
+++ b/lib/sys/mmap.h
@@ -10,7 +10,8 @@
 #define MAP_SHARED  0x1
 #define MAP_PRIVATE 0x2
 
-static void * mmap(void * addr, unsigned long size, int prot, int flags, int fd, int offset) {
+static void * mmap(void * addr, unsigned long size, int prot, int flags, int fd, int offset)
+{
 	return syscall(MMAP, size, prot, flags, fd, offset);
 }
 
diff --git a/lib/sys/munmap.h b/lib/sys/munmap.h
index 4a876d6..1d30fa2 100644
--- a/lib/sys/munmap.h
+++ b/lib/sys/munmap.h
@@ -2,7 +2,8 @@
 #define MUNMAP_H
 #include "syscall.h"
 
-static int munmap(void * addr, unsigned long size) {
+static int munmap(void * addr, unsigned long size)
+{
 	return syscall(MUNMAP, addr, size);
 }
 
diff --git a/lib/sys/pipe.h b/lib/sys/pipe.h
index f95f366..029d6bb 100644
--- a/lib/sys/pipe.h
+++ b/lib/sys/pipe.h
@@ -6,7 +6,7 @@
 #define PIPE_IN  1
 #define PIPE_OUT 0
 
-int pipe(int *filedes)
+static int pipe(int *filedes)
 {
 	return syscall(PIPE, filedes);
 }
diff --git a/lib/sys/read.h b/lib/sys/read.h
index 7dba6e7..61e5576 100644
--- a/lib/sys/read.h
+++ b/lib/sys/read.h
@@ -2,7 +2,8 @@
 #define READ_H
 #include "syscalls.h"
 
-static int read(unsigned int fd, char * buf, unsigned long count) {
+static int read(unsigned int fd, char * buf, unsigned long count)
+{
 	return syscall(READ, fd, buf, count, 0, 0);
 }
 
diff --git a/lib/sys/reboot.h b/lib/sys/reboot.h
index fd119c5..22893ca 100644
--- a/lib/sys/reboot.h
+++ b/lib/sys/reboot.h
@@ -11,7 +11,8 @@
 #define REBOOT_SUSPEND     0xd000fce2
 #define REBOOT_NEW_KERNEL  0x45584543
 
-static int reboot(int cmd) {
+static int reboot(int cmd)
+{
 	const int magic1 = 0xfee1dead;
 	const int magic2 =  537993216;
 
diff --git a/lib/sys/sbrk.h b/lib/sys/sbrk.h
index 25d9c6c..159c644 100644
--- a/lib/sys/sbrk.h
+++ b/lib/sys/sbrk.h
@@ -3,7 +3,8 @@
 
 #include "syscalls.h"
 
-static int brk(void * addr) {
+static int brk(void * addr)
+{
 	return syscall(BRK, addr);
 }
 
diff --git a/lib/sys/start.S b/lib/sys/start.S
index deafd67..1faf691 100644
--- a/lib/sys/start.S
+++ b/lib/sys/start.S
@@ -1,6 +1,10 @@
 .global _start
 _start:
+	mov (%rsp), %rdi
+	xor %rax, %rax
+	lea 8(%rsp, %rax, 8), %rsi
+	lea 16(%rsp, %rdi, 8), %rdx
 	call main
-	mov %rax, %rdi
+	mov $0, %rdi
 	mov $60, %rax
 	syscall
diff --git a/lib/sys/stat.h b/lib/sys/stat.h
index 02bdc48..a6aa9a8 100644
--- a/lib/sys/stat.h
+++ b/lib/sys/stat.h
@@ -55,7 +55,8 @@ struct stat {
 	u64 __[3];
 };
 
-static int stat(const char * filename, struct stat * statbuf) {
+static int stat(const char * filename, struct stat * statbuf)
+{
 	return syscall(STAT, filename, statbuf);
 }
 
diff --git a/lib/sys/write.h b/lib/sys/write.h
index 59f7789..6ad748e 100644
--- a/lib/sys/write.h
+++ b/lib/sys/write.h
@@ -3,7 +3,8 @@
 
 #include "syscalls.h"
 
-static int write(unsigned int fd, const char * buf, unsigned long count) {
+static int write(unsigned int fd, const char * buf, unsigned long count)
+{
 	return syscall(WRITE, fd, buf, count);
 }
 
-- 
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