Re: [PATCH 09/11] sandbox: Add a way to map a file into memory

[Simon Glass]

Hi Marek,

On Wed, 22 Sept 2021 at 20:09, Tom Rini  wrote:
>
> On Wed, Aug 18, 2021 at 09:40:31PM -0600, Simon Glass wrote:
>
> > It is useful to map a file into memory so that it can be accessed using
> > simple pointers. Add a function to support this.
> >
> > Signed-off-by: Simon Glass 
>
> Applied to u-boot/next, thanks!

I'll send a new patch for your comment. I have it locally but the mmc
malloc() thing needs a substantial effort to resolve, so I'm not sure
when I'll send this.

Regards,
Simon

Re: [PATCH 09/11] sandbox: Add a way to map a file into memory

[Tom Rini]

On Wed, Aug 18, 2021 at 09:40:31PM -0600, Simon Glass wrote:

> It is useful to map a file into memory so that it can be accessed using
> simple pointers. Add a function to support this.
> 
> Signed-off-by: Simon Glass 

Applied to u-boot/next, thanks!

-- 
Tom


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Re: [PATCH 09/11] sandbox: Add a way to map a file into memory

[Marek Behún]

On Wed, 18 Aug 2021 21:40:31 -0600
Simon Glass  wrote:

> It is useful to map a file into memory so that it can be accessed using
> simple pointers. Add a function to support this.
> 
> Signed-off-by: Simon Glass 

> +int os_map_file(const char *pathname, int os_flags, void **bufp, int *sizep)
> +{
> + void *ptr;
> + int size;
> + int ifd;
> +
> + ifd = os_open(pathname, os_flags);
> + if (ifd < 0) {
> + printf("Cannot open file '%s'\n", pathname);
> + return -EIO;
> + }
> + size = os_filesize(ifd);
> + if (size < 0) {
> + printf("Cannot get file size of '%s'\n", pathname);
> + return -EIO;
> + }
> +
> + ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, ifd, 0);
> + if (ptr == MAP_FAILED) {
> + printf("Can't map file '%s': %s\n", pathname, strerror(errno));
> + return -EPERM;
> + }
> +
> + *bufp = ptr;
> + *sizep = size;
> +
> + return 0;
> +}

You need to close the file descriptor after mmapping.

Marek

[PATCH 09/11] sandbox: Add a way to map a file into memory

[Simon Glass]

It is useful to map a file into memory so that it can be accessed using
simple pointers. Add a function to support this.

Signed-off-by: Simon Glass 
---

 arch/sandbox/cpu/os.c | 29 +
 include/os.h  | 13 +
 2 files changed, 42 insertions(+)

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index a4262881c54..b72dafca2ba 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -182,6 +182,35 @@ err:
return ret;
 }
 
+int os_map_file(const char *pathname, int os_flags, void **bufp, int *sizep)
+{
+   void *ptr;
+   int size;
+   int ifd;
+
+   ifd = os_open(pathname, os_flags);
+   if (ifd < 0) {
+   printf("Cannot open file '%s'\n", pathname);
+   return -EIO;
+   }
+   size = os_filesize(ifd);
+   if (size < 0) {
+   printf("Cannot get file size of '%s'\n", pathname);
+   return -EIO;
+   }
+
+   ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, ifd, 0);
+   if (ptr == MAP_FAILED) {
+   printf("Can't map file '%s': %s\n", pathname, strerror(errno));
+   return -EPERM;
+   }
+
+   *bufp = ptr;
+   *sizep = size;
+
+   return 0;
+}
+
 /* Restore tty state when we exit */
 static struct termios orig_term;
 static bool term_setup;
diff --git a/include/os.h b/include/os.h
index 7661078d336..770d76e02f7 100644
--- a/include/os.h
+++ b/include/os.h
@@ -406,6 +406,19 @@ int os_write_file(const char *name, const void *buf, int 
size);
  */
 int os_read_file(const char *name, void **bufp, int *sizep);
 
+/**
+ * os_map_file() - Map a file from the host filesystem into memory
+ *
+ * This can be useful when to provide a backing store for an emulated device
+ *
+ * @pathname:  File pathname to map
+ * @os_flags:  Flags, like OS_O_RDONLY, OS_O_RDWR
+ * @bufp:  Returns buffer containing the file
+ * @sizep: Returns size of data
+ * Return: 0 if OK, -ve on error
+ */
+int os_map_file(const char *pathname, int os_flags, void **bufp, int *sizep);
+
 /*
  * os_find_text_base() - Find the text section in this running process
  *
-- 
2.33.0.rc1.237.g0d66db33f3-goog