2 files changed, 40 insertions, 0 deletions

diff --git a/firmware/common/inflate.c b/firmware/common/inflate.c
index 26fd191690..62661ee111 100644
--- a/firmware/common/inflate.c
+++ b/firmware/common/inflate.c
@@ -43,6 +43,7 @@
 
 #include "inflate.h"
 #include <stdbool.h>
+#include <string.h>
 #include "adler32.h"
 #include "crc32.h"
 #include "system.h"
@@ -757,3 +758,27 @@ int inflate(struct inflate* it, int st, inflate_reader read, void* rctx, inflate
 
     return inflate_blocks(it, st, read, rctx, write, wctx);
 }
+
+static uint32_t inflate_buffer_rw(struct inflate_bufferctx* c,
+                                  void* dst, const void* src, uint32_t block_size)
+{
+    size_t size_left = c->end - c->buf;
+    size_t copy_size = MIN((size_t)block_size, size_left);
+
+    memcpy(dst, src, copy_size);
+    c->buf += copy_size;
+
+    return copy_size;
+}
+
+uint32_t inflate_buffer_reader(void* block, uint32_t block_size, void* ctx)
+{
+    struct inflate_bufferctx* c = ctx;
+    return inflate_buffer_rw(c, block, c->buf, block_size);
+}
+
+uint32_t inflate_buffer_writer(const void* block, uint32_t block_size, void* ctx)
+{
+    struct inflate_bufferctx* c = ctx;
+    return inflate_buffer_rw(c, c->buf, block, block_size);
+}
diff --git a/firmware/include/inflate.h b/firmware/include/inflate.h
index b56ccf181a..7dae0448e3 100644
--- a/firmware/include/inflate.h
+++ b/firmware/include/inflate.h
@@ -23,6 +23,7 @@
 #define _INFLATE_H_
 
 #include <stdint.h>
+#include <stddef.h>
 
 enum {
     INFLATE_RAW,
@@ -43,4 +44,18 @@ extern const uint32_t inflate_align;
 // see above enum for possible options.
 int inflate(struct inflate* it, int st, inflate_reader read, void* rctx, inflate_writer write, void* wctx);
 
+struct inflate_bufferctx {
+    // initialize this with your input/output buffer.
+    // the pointer is updated as data is read or written.
+    void* buf;
+
+    // buffer end marker (= buf + buf_size).
+    void* end;
+};
+
+// reader and writer for using an in-memory buffer.
+// Use 'inflate_bufferctx' as the context argument.
+uint32_t inflate_buffer_reader(void* block, uint32_t block_size, void* ctx);
+uint32_t inflate_buffer_writer(const void* block, uint32_t block_size, void* ctx);
+
 #endif