diff --git a/include/chipdrivers/probing.h b/include/chipdrivers/probing.h
index 090f2ab..2e081d1 100644
--- a/include/chipdrivers/probing.h
+++ b/include/chipdrivers/probing.h
@@ -88,4 +88,10 @@
 void flashprog_bus_probe(struct registered_master *, const struct flashchip *);
 bool flashprog_chip_match(struct registered_master *, const struct flashchip *);
 
+struct flashprog_chips;
+struct flashprog_flashctx;
+struct flashprog_programmer;
+const struct master_common *flashprog_chip_probe(const struct flashprog_programmer *, const struct flashchip *);
+int flashprog_flash_prepare_context(struct flashprog_flashctx **, const struct flashprog_programmer *, const struct master_common *, const struct flashchip *);
+
 #endif /* !__PROBING_H__ */
diff --git a/include/flash.h b/include/flash.h
index 3ad9d1f..31b4f0c 100644
--- a/include/flash.h
+++ b/include/flash.h
@@ -440,10 +440,10 @@
 	uintptr_t physical_registers;
 	chipaddr virtual_registers;
 	union {
-		struct master_common *common;
-		struct par_master *par;
-		struct spi_master *spi;
-		struct opaque_master *opaque;
+		const struct master_common *common;
+		const struct par_master *par;
+		const struct spi_master *spi;
+		const struct opaque_master *opaque;
 	} mst;
 	const struct flashprog_layout *layout;
 	struct flashprog_layout *default_layout;
diff --git a/include/libflashprog.h b/include/libflashprog.h
index 8afd8d5..6f4193b 100644
--- a/include/libflashprog.h
+++ b/include/libflashprog.h
@@ -122,6 +122,8 @@
 
 struct flashprog_flashctx;
 int flashprog_flash_probe(struct flashprog_flashctx **, const struct flashprog_programmer *, const char *chip_name);
+__attribute__((nonnull))
+int flashprog_flash_probe_chip(struct flashprog_flashctx **, const struct flashprog_programmer *, const struct flashprog_chip *);
 size_t flashprog_flash_getsize(const struct flashprog_flashctx *);
 int flashprog_flash_erase(struct flashprog_flashctx *);
 void flashprog_flash_release(struct flashprog_flashctx *);