Add romfile_size() wrapper for accessing cbfs/qemu_cfg files.

2 files changed, 15 insertions, 2 deletions

diff --git a/src/paravirt.c b/src/paravirt.c
index 00ff58ca..da72c71d 100644
--- a/src/paravirt.c
+++ b/src/paravirt.c
@@ -339,14 +339,21 @@ u32 qemu_cfg_find_file(const char *name)
     return __cfg_next_prefix_file(name, strlen(name) + 1, 0);
 }
 
+int qemu_cfg_size_file(u32 select)
+{
+    if (select != ntohs(LastFile.select))
+        return -1;
+    return ntohl(LastFile.size);
+}
+
 int qemu_cfg_read_file(u32 select, void *dst, u32 maxlen)
 {
     if (!qemu_cfg_present)
         return -1;
     if (!select || select != ntohs(LastFile.select))
         return -1;
-    int len = ntohl(LastFile.size);
-    if (len > maxlen)
+    int len = qemu_cfg_size_file(select);
+    if (len < 0 || len > maxlen)
         return -1;
     qemu_cfg_read_entry(dst, select, len);
     return len;
diff --git a/src/paravirt.h b/src/paravirt.h
index 83fe8ecf..7d4bc026 100644
--- a/src/paravirt.h
+++ b/src/paravirt.h
@@ -70,6 +70,7 @@ struct e820_reservation {
 
 u32 qemu_cfg_next_prefix_file(const char *prefix, u32 prevselect);
 u32 qemu_cfg_find_file(const char *name);
+int qemu_cfg_size_file(u32 select);
 int qemu_cfg_read_file(u32 select, void *dst, u32 maxlen);
 
 // Wrappers that select cbfs or qemu_cfg file interface.
@@ -83,6 +84,11 @@ static inline u32 romfile_find(const char *name) {
         return (u32)cbfs_finddatafile(name);
     return qemu_cfg_find_file(name);
 }
+static inline u32 romfile_size(u32 fileid) {
+    if (CONFIG_COREBOOT)
+        return cbfs_datasize((void*)fileid);
+    return qemu_cfg_size_file(fileid);
+}
 static inline int romfile_copy(u32 fileid, void *dst, u32 maxlen) {
     if (CONFIG_COREBOOT)
         return cbfs_copyfile((void*)fileid, dst, maxlen);