[SeaBIOS] [PATCH v4 2/5] pmm: support looking up a given pattern in FSEG

Michael S. Tsirkin mst at redhat.com
Mon Sep 23 20:20:28 CEST 2013


Will be used to find RSDP there.

Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
---
 src/malloc.h |  1 +
 src/malloc.c | 20 +++++++++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/malloc.h b/src/malloc.h
index af8a21d..feb8938 100644
--- a/src/malloc.h
+++ b/src/malloc.h
@@ -19,6 +19,7 @@ void *_malloc(struct zone_s *zone, u32 handle, u32 size, u32 align);
 int _free(void *data);
 u32 malloc_getspace(struct zone_s *zone);
 void *malloc_find(u32 handle);
+void *malloc_find_fseg_pattern(void *pattern, unsigned pattern_size);
 
 #define MALLOC_DEFAULT_HANDLE 0xFFFFFFFF
 // Minimum alignment of malloc'd memory
diff --git a/src/malloc.c b/src/malloc.c
index 281f41e..d150c90 100644
--- a/src/malloc.c
+++ b/src/malloc.c
@@ -12,7 +12,7 @@
 #include "output.h" // dprintf
 #include "stacks.h" // wait_preempt
 #include "std/optionrom.h" // OPTION_ROM_ALIGN
-#include "string.h" // memset
+#include "string.h" // memset, memcmp
 
 // Information on a reserved area.
 struct allocinfo_s {
@@ -273,6 +273,24 @@ _free(void *data)
     return 0;
 }
 
+// Find the data block in zone matching a given pattern.
+void *malloc_find_fseg_pattern(void *pattern, unsigned pattern_size)
+{
+    struct allocinfo_s *info;
+    hlist_for_each_entry(info, &ZoneFSeg.head, node) {
+        unsigned space = info->dataend - info->data;
+        int off;
+
+        if (space < pattern_size)
+            continue;
+        for (off = 0; off < space - pattern_size; ++off) {
+            if (!memcmp(info->data + off, pattern, pattern_size))
+                return info->data + off;
+        }
+    }
+    return NULL;
+}
+
 // Find the amount of free space in a given zone.
 u32
 malloc_getspace(struct zone_s *zone)
-- 
MST




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