From b9274095c2cd1ae42f232c823e9e9557696be91a Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 18 Aug 2021 21:40:31 -0600 Subject: [PATCH] sandbox: Add a way to map a file into memory 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 a426288..b72dafc 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 7661078..770d76e 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 * -- 2.7.4