[PATCH 09/11] sandbox: Add a way to map a file into memory
Simon Glass
sjg at chromium.org
Thu Aug 19 05:40:31 CEST 2021
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 <sjg at chromium.org>
---
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
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