[SeaBIOS] [PATCH 1/2] romfile: implement a generic loader

[Riku Viitanen]

romfile_loadfile_g:
Based on romfile_loadfile but more flexible. User has to supply pointer
to a malloc function and the number of trailing padding bytes. Thus, any
memory region may be used.

romfile_loadfile:
It is now a wrapper around romfile_loadfile_g. Functionality is the same.

Signed-off-by: Riku Viitanen 
---
 src/romfile.c | 25 ++++++++++++++++++++-----
 src/romfile.h |  2 ++
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/romfile.c b/src/romfile.c
index b598274e..8bf95713 100644
--- a/src/romfile.c
+++ b/src/romfile.c
@@ -47,10 +47,12 @@ romfile_find(const char *name)
     return __romfile_findprefix(name, strlen(name) + 1, NULL);
 }

-// Helper function to find, malloc_tmphigh, and copy a romfile.  This
-// function adds a trailing zero to the malloc'd copy.
+// Generic function to find romfile, malloc (using provided function
+// pointer), and copy a romfile. add_len specifies how many additional
+// trailing bytes to reserve. The extra bytes will not be initialised.
 void *
-romfile_loadfile(const char *name, int *psize)
+romfile_loadfile_g(const char *name, int *psize,
+                   void *(*malloc_fn)(), int add_len)
 {
     struct romfile_s *file = romfile_find(name);
     if (!file)
@@ -60,7 +62,7 @@ romfile_loadfile(const char *name, int *psize)
     if (!filesize)
         return NULL;

-    char *data = malloc_tmphigh(filesize+1);
+    char *data = malloc_fn(filesize+add_len);
     if (!data) {
         warn_noalloc();
         return NULL;
@@ -74,7 +76,20 @@ romfile_loadfile(const char *name, int *psize)
     }
     if (psize)
         *psize = filesize;
-    data[filesize] = '\0';
+
+    return data;
+}
+
+// Helper function to find, malloc_tmphigh, and copy a romfile.  This
+// function adds a trailing zero to the malloc'd copy.
+void *
+romfile_loadfile(const char *name, int *psize)
+{
+    char *data = romfile_loadfile_g(name, psize, &malloc_tmphigh, 1);
+    if (!data)
+        return NULL;
+
+    data[*psize] = '\0';
     return data;
 }

diff --git a/src/romfile.h b/src/romfile.h
index 3e0f8200..a320a5bc 100644
--- a/src/romfile.h
+++ b/src/romfile.h
@@ -13,6 +13,8 @@ struct romfile_s {
 void romfile_add(struct romfile_s *file);
 struct romfile_s *romfile_findprefix(const char *prefix, struct romfile_s *prev);
 struct romfile_s *romfile_find(const char *name);
+void *romfile_loadfile_g(const char *name, int *psize,
+                         void *(*malloc_fn)(), int add_len);
 void *romfile_loadfile(const char *name, int *psize);
 u64 romfile_loadint(const char *name, u64 defval);