From 6bdfd7c992b2345f964dc6bc5dbb4189e36a5e99 Mon Sep 17 00:00:00 2001
From: Wojtek Kosior <kwojtus@protonmail.com>
Date: Fri, 27 Dec 2019 22:09:21 +0100
Subject: add userspace tool for creating ramfs image

---
 .gitignore |  1 +
 Makefile   |  3 +++
 makefs.c   | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 71 insertions(+)
 create mode 100644 makefs.c

diff --git a/.gitignore b/.gitignore
index db6eb43..480597b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 *.elf
 *.img
 pipe_image
+makefs
diff --git a/Makefile b/Makefile
index d782eda..3d6b095 100644
--- a/Makefile
+++ b/Makefile
@@ -46,6 +46,9 @@ run-on-rpi : kernel.img pipe_image
 pipe_image : pipe_image.c lib/rs232/rs232.c
 	gcc -Wall -std=gnu99 -O3 $^ -o $@
 
+makefs : makefs.c
+	gcc -Wall -std=gnu99 -O3 $^ -o $@
+
 clean :
 	-rm *.img *.elf *.o pipe_image
 
diff --git a/makefs.c b/makefs.c
new file mode 100644
index 0000000..7d5b148
--- /dev/null
+++ b/makefs.c
@@ -0,0 +1,67 @@
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <err.h>
+#include <sys/stat.h>
+#include <string.h>
+
+#define ANSI_FG_RED "\033[0;31m"
+#define ANSI_FG_DEFAULT "\033[0;39m"
+
+int main(int argc, char **argv)
+{
+  for (int i = 1; i < argc; i++)
+    {
+      struct stat fileinfo;
+      
+      if (stat(argv[i], &fileinfo))
+	err(-1, "couldn't stat " ANSI_FG_RED "%s" ANSI_FG_DEFAULT,
+	    argv[i]);
+	
+      if (!S_ISREG(fileinfo.st_mode))
+	errx(-1, ANSI_FG_RED "%s" ANSI_FG_DEFAULT
+	     " is not a regular file.", argv[i]);
+
+      if (fileinfo.st_size > UINT32_MAX)
+	errx(-1, ANSI_FG_RED "%s" ANSI_FG_DEFAULT
+	     " is too big.", argv[i]);
+      
+      uint32_t file_size = fileinfo.st_size;
+      uint32_t name_size = strlen(argv[i]);
+      
+      if (fwrite(&name_size, 4, 1, stdout) != 1)
+	errx(-1, "error writing to stdout");
+
+      if (printf("%s", argv[i]) != name_size)
+	errx(-1, "error writing to stdout");
+
+      if (fwrite(&file_size, 4, 1, stdout) != 1)
+	errx(-1, "error writing to stdout");
+
+      if (fflush(stdout))
+	err(-1, "couldn't flush stdout");
+      
+      pid_t pid;
+      int wstatus;
+      switch (pid = fork())
+	{
+	case -1:
+	  err(-1, "couldn't fork");
+	case 0:
+	  if (execlp("cat", "cat", argv[i], NULL))
+	    err(-1, "couldn't execute cat");
+	default:
+	  if (wait(&wstatus) == -1)
+	    err(-1, "error waiting for child");
+
+	  if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus))
+	    exit(-1);
+	}
+    }
+  
+  return 0;
+}
+
-- 
cgit v1.2.3