From c67c34e0eaa697da81de80e46547893950b28a83 Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@proton.me>
Date: Tue, 10 Sep 2024 13:08:41 -0400
Subject: [PATCH] Add sys_hello and testbin/hellotest

`sys_hello` is a new syscall that just prints some text in the terminal.

`testbin/hellotest` is a userland binary that just calls `sys_hello`
---
 kern/arch/mips/syscall/syscall.c    |  3 +++
 kern/conf/conf.kern                 |  1 +
 kern/include/kern/syscall.h         |  1 +
 kern/include/syscall.h              |  2 ++
 kern/syscall/hello.c                |  7 +++++++
 userland/include/unistd.h           |  2 ++
 userland/testbin/Makefile           |  2 +-
 userland/testbin/hellotest/Makefile | 11 +++++++++++
 userland/testbin/hellotest/hello.c  |  8 ++++++++
 9 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 kern/syscall/hello.c
 create mode 100644 userland/testbin/hellotest/Makefile
 create mode 100644 userland/testbin/hellotest/hello.c

diff --git a/kern/arch/mips/syscall/syscall.c b/kern/arch/mips/syscall/syscall.c
index b42d9c0..5c13836 100644
--- a/kern/arch/mips/syscall/syscall.c
+++ b/kern/arch/mips/syscall/syscall.c
@@ -104,6 +104,9 @@ void syscall(struct trapframe *tf) {
   case SYS___time:
     err = sys___time((userptr_t)tf->tf_a0, (userptr_t)tf->tf_a1);
     break;
+  case SYS_hello:
+    err = sys_hello();
+    break;
 
   case SYS__exit:
     err = 0;
diff --git a/kern/conf/conf.kern b/kern/conf/conf.kern
index ad58977..1edca92 100644
--- a/kern/conf/conf.kern
+++ b/kern/conf/conf.kern
@@ -379,6 +379,7 @@ file      vfs/devnull.c
 file      syscall/loadelf.c
 file      syscall/runprogram.c
 file      syscall/time_syscalls.c
+file      syscall/hello.c
 
 #
 # Startup and initialization
diff --git a/kern/include/kern/syscall.h b/kern/include/kern/syscall.h
index 53a2b45..94b17c0 100644
--- a/kern/include/kern/syscall.h
+++ b/kern/include/kern/syscall.h
@@ -94,6 +94,7 @@
 // #define SYS_getpriority 38
 // #define SYS_setpriority 39
 //                               (process groups, sessions, and job control)
+#define SYS_hello 41
 // #define SYS_getpgid    40
 // #define SYS_setpgid    41
 // #define SYS_getsid     42
diff --git a/kern/include/syscall.h b/kern/include/syscall.h
index 6cd517b..b5620a9 100644
--- a/kern/include/syscall.h
+++ b/kern/include/syscall.h
@@ -57,4 +57,6 @@ __DEAD void enter_new_process(int argc, userptr_t argv, userptr_t env,
 int sys_reboot(int code);
 int sys___time(userptr_t user_seconds, userptr_t user_nanoseconds);
 
+int sys_hello(void);
+
 #endif /* _SYSCALL_H_ */
diff --git a/kern/syscall/hello.c b/kern/syscall/hello.c
new file mode 100644
index 0000000..842ff45
--- /dev/null
+++ b/kern/syscall/hello.c
@@ -0,0 +1,7 @@
+#include <types.h>
+#include <lib.h>
+#include <syscall.h>
+int sys_hello(void) {
+  kprintf("Hello CSE4001!\n");
+  return 0;
+}
diff --git a/userland/include/unistd.h b/userland/include/unistd.h
index 9739344..70f68b5 100644
--- a/userland/include/unistd.h
+++ b/userland/include/unistd.h
@@ -156,4 +156,6 @@ int execvp(const char *prog, char *const *args); /* calls execv */
 char *getcwd(char *buf, size_t buflen);          /* calls __getcwd */
 time_t time(time_t *seconds);                    /* calls __time */
 
+int hello(void);
+
 #endif /* _UNISTD_H_ */
diff --git a/userland/testbin/Makefile b/userland/testbin/Makefile
index 647f229..0ddc3e8 100644
--- a/userland/testbin/Makefile
+++ b/userland/testbin/Makefile
@@ -7,7 +7,7 @@ TOP=../..
 
 SUBDIRS=add argtest badcall bigexec bigfile bigfork bigseek bloat conman \
 	crash ctest dirconc dirseek dirtest f_test factorial farm faulter \
-	filetest forkbomb forktest frack hash hog huge \
+	filetest forkbomb forktest frack hash hellotest hog huge \
 	malloctest matmult multiexec palin parallelvm poisondisk psort \
 	randcall redirect rmdirtest rmtest \
 	sbrktest schedpong sort sparsefile tail tictac triplehuge \
diff --git a/userland/testbin/hellotest/Makefile b/userland/testbin/hellotest/Makefile
new file mode 100644
index 0000000..3768414
--- /dev/null
+++ b/userland/testbin/hellotest/Makefile
@@ -0,0 +1,11 @@
+# Makefile for hello
+
+TOP=../../..
+.include "$(TOP)/mk/os161.config.mk"
+
+PROG=hellotest
+SRCS=hello.c
+BINDIR=/testbin
+
+.include "$(TOP)/mk/os161.prog.mk"
+
diff --git a/userland/testbin/hellotest/hello.c b/userland/testbin/hellotest/hello.c
new file mode 100644
index 0000000..fbea19a
--- /dev/null
+++ b/userland/testbin/hellotest/hello.c
@@ -0,0 +1,8 @@
+#include <unistd.h>
+
+extern int hello(void);
+
+int main() {
+  hello();
+  return 0;
+}