From bb2c2aaee584a50eeec66e7f8a28f13c9c808a20 Mon Sep 17 00:00:00 2001
From: assaf <asssaf@localhost>
Date: Sun, 8 Oct 2023 17:48:32 -0700
Subject: [PATCH] initial import

---
 .gitignore        |  6 ++++++
 Makefile          | 32 +++++++++++++++++++++++++++++++
 docker/Dockerfile |  9 +++++++++
 scripts/build.sh  |  3 +++
 tryboot.c         | 48 +++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 98 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Makefile
 create mode 100644 docker/Dockerfile
 create mode 100755 scripts/build.sh
 create mode 100644 tryboot.c

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..caa7c46
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,6 @@
+qemu-arm
+extension
+tryboot
+tryboot.tcz
+tryboot.tcz.list
+tryboot.tcz.md5.txt
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..5a0699e
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,32 @@
+SRC := tryboot.c
+BIN := tryboot
+EXTDIR := extension
+TCZ := $(BIN).tcz
+LIST := $(TCZ).list
+MD5 := $(TCZ).md5.txt
+
+all: tryboot.tcz.list tryboot.tcz.md5.txt
+
+
+$(BIN): $(SRC)
+	gcc $(STATIC) -I/usr/include -o $(BIN) $(SRC)
+
+
+$(EXTDIR): $(BIN)
+	install -D $(BIN) $(EXTDIR)/usr/local/bin/$(BIN)
+
+
+$(TCZ): $(EXTDIR)
+	mksquashfs $(EXTDIR) $(TCZ) -all-root -noappend
+
+
+$(LIST): $(TCZ)
+	unsquashfs -lc $(TCZ) | sed 's|^squashfs-root/||' > $(LIST)
+
+
+$(MD5): $(TCZ)
+	md5sum $(TCZ) > $(MD5)
+
+
+clean:
+	rm -r $(BIN) $(EXTDIR) $(TCZ) $(LIST) $(MD5)
diff --git a/docker/Dockerfile b/docker/Dockerfile
new file mode 100644
index 0000000..1fc9f3e
--- /dev/null
+++ b/docker/Dockerfile
@@ -0,0 +1,9 @@
+FROM --platform=linux/arm/v5 debian:stable
+
+# a static-user qemu binary that allows running the container on x86
+# (the binary is not included in this git repository, build or download your own)
+COPY qemu-arm /usr/bin
+
+RUN apt-get update \
+	&& apt-get install -y build-essential squashfs-tools \
+	&& apt-get clean
diff --git a/scripts/build.sh b/scripts/build.sh
new file mode 100755
index 0000000..f4953f4
--- /dev/null
+++ b/scripts/build.sh
@@ -0,0 +1,3 @@
+docker build -t builder -f docker/Dockerfile .
+
+docker run --rm -it -v $PWD:/mnt -w /mnt -u $(id -u):$(id -g) builder make
diff --git a/tryboot.c b/tryboot.c
new file mode 100644
index 0000000..6d0188c
--- /dev/null
+++ b/tryboot.c
@@ -0,0 +1,48 @@
+#define _GNU_SOURCE
+
+#include <linux/unistd.h>
+#include <linux/reboot.h>
+#include <sys/syscall.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+
+int main(int argc, char *argv[])  {
+    char *param = NULL;
+    int cmd;
+
+    if(argc == 2) {
+        param = argv[1];
+        cmd = LINUX_REBOOT_CMD_RESTART2;
+    }
+    else {
+        cmd = LINUX_REBOOT_CMD_RESTART;
+    }
+
+    // prevent being killed when parent dies
+    int rc = daemon(0, 1);
+    if (rc == -1) {
+        perror("daemon() failed");
+        return 1;
+    }
+
+    // write current pid to the killall5 skip file
+    pid_t pid = getpid();
+
+    FILE *k5skip = fopen("/var/tmp/k5_skip", "a");
+    fprintf(k5skip, "%d\n", pid);
+    fclose(k5skip);
+
+    system("/etc/init.d/rc.shutdown");
+
+    sync();
+    printf("Calling reboot syscall...\n");
+
+    // calling reboot() doesn't work, need to use syscall()
+    //int rc = reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, param);
+    //printf("After reboot: rc=%d, errno=%d\n", rc, errno);
+    syscall(SYS_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, param);
+
+    return 0;
+}