[U-Boot] [PATCH 1/2] fit: Support FDT compression

[Julius Werner]

This patch adds support for compressing FDT image nodes in a FIT image
(equivalent to how kernel nodes can already be compressed). This can
reduce the size of FIT images (and therefore improve boot times). FDTs
will automatically get decompressed on load.

This patch does not support extracting compatible strings from
compressed FDTs, so it's not very helpful in conjunction with
CONFIG_FIT_BEST_MATCH yet, but it can already be used in environments
that select the configuration to load explicitly.

Signed-off-by: Julius Werner <jwerner at chromium.org>
---
 common/image-fit.c | 85 +++++++++++++++++++++++++++-------------------
 1 file changed, 51 insertions(+), 34 deletions(-)

diff --git a/common/image-fit.c b/common/image-fit.c
index ac901e131c..20e02d240b 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -22,6 +22,7 @@
 DECLARE_GLOBAL_DATA_PTR;
 #endif /* !USE_HOSTCC*/
 
+#include <bootm.h>
 #include <image.h>
 #include <bootstage.h>
 #include <u-boot/crc.h>
@@ -1576,6 +1577,13 @@ int fit_conf_find_compat(const void *fit, const void *fdt)
 			      kfdt_name);
 			continue;
 		}
+
+		if (!fit_image_check_comp(fit, kfdt_noffset, IH_COMP_NONE)) {
+			debug("Can't extract compat from \"%s\" (compressed)\n",
+			      kfdt_name);
+			continue;
+		}
+
 		/*
 		 * Get a pointer to this configuration's fdt.
 		 */
@@ -1795,11 +1803,12 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 	const char *fit_uname_config;
 	const char *fit_base_uname_config;
 	const void *fit;
-	const void *buf;
+	void *buf;
+	void *loadbuf;
 	size_t size;
 	int type_ok, os_ok;
-	ulong load, data, len;
-	uint8_t os;
+	ulong load, load_end, data, len;
+	uint8_t os, comp;
 #ifndef USE_HOSTCC
 	uint8_t os_arch;
 #endif
@@ -1895,12 +1904,6 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 	images->os.arch = os_arch;
 #endif
 
-	if (image_type == IH_TYPE_FLATDT &&
-	    !fit_image_check_comp(fit, noffset, IH_COMP_NONE)) {
-		puts("FDT image is compressed");
-		return -EPROTONOSUPPORT;
-	}
-
 	bootstage_mark(bootstage_id + BOOTSTAGE_SUB_CHECK_ALL);
 	type_ok = fit_image_check_type(fit, noffset, image_type) ||
 		  fit_image_check_type(fit, noffset, IH_TYPE_FIRMWARE) ||
@@ -1931,7 +1934,8 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 	bootstage_mark(bootstage_id + BOOTSTAGE_SUB_CHECK_ALL_OK);
 
 	/* get image data address and length */
-	if (fit_image_get_data_and_size(fit, noffset, &buf, &size)) {
+	if (fit_image_get_data_and_size(fit, noffset,
+					(const void **)&buf, &size)) {
 		printf("Could not find %s subimage data!\n", prop_name);
 		bootstage_error(bootstage_id + BOOTSTAGE_SUB_GET_DATA);
 		return -ENOENT;
@@ -1939,30 +1943,15 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 
 #if !defined(USE_HOSTCC) && defined(CONFIG_FIT_IMAGE_POST_PROCESS)
 	/* perform any post-processing on the image data */
-	board_fit_image_post_process((void **)&buf, &size);
+	board_fit_image_post_process(&buf, &size);
 #endif
 
 	len = (ulong)size;
 
-	/* verify that image data is a proper FDT blob */
-	if (image_type == IH_TYPE_FLATDT && fdt_check_header(buf)) {
-		puts("Subimage data is not a FDT");
-		return -ENOEXEC;
-	}
-
 	bootstage_mark(bootstage_id + BOOTSTAGE_SUB_GET_DATA_OK);
 
-	/*
-	 * Work-around for eldk-4.2 which gives this warning if we try to
-	 * cast in the unmap_sysmem() call:
-	 * warning: initialization discards qualifiers from pointer target type
-	 */
-	{
-		void *vbuf = (void *)buf;
-
-		data = map_to_sysmem(vbuf);
-	}
-
+	data = map_to_sysmem(buf);
+	load = data;
 	if (load_op == FIT_LOAD_IGNORED) {
 		/* Don't load */
 	} else if (fit_image_get_load(fit, noffset, &load)) {
@@ -1974,8 +1963,6 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 		}
 	} else if (load_op != FIT_LOAD_OPTIONAL_NON_ZERO || load) {
 		ulong image_start, image_end;
-		ulong load_end;
-		void *dst;
 
 		/*
 		 * move image data to the load address,
@@ -1993,14 +1980,44 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 
 		printf("   Loading %s from 0x%08lx to 0x%08lx\n",
 		       prop_name, data, load);
+	}
 
-		dst = map_sysmem(load, len);
-		memmove(dst, buf, len);
-		data = load;
+	/*
+	 * Decompress FDTs right here. Kernel images get decompressed later in
+	 * bootm_host_load_image().
+	 */
+	comp = IH_COMP_NONE;
+	loadbuf = buf;
+	if (image_type == IH_TYPE_FLATDT &&
+	    !fit_image_get_comp(fit, noffset, &comp) &&
+	    comp != IH_COMP_NONE) {
+	    	ulong max_decomp_len = len * 20;
+		if (load == data) {
+			loadbuf = malloc(max_decomp_len);
+			load = map_to_sysmem(loadbuf);
+		} else {
+			loadbuf = map_sysmem(load, max_decomp_len);
+		}
+		if (bootm_decomp_image(comp, load, data, IH_TYPE_FLATDT,
+				loadbuf, buf, len, max_decomp_len, &load_end)) {
+			printf("Error: Cannot decompress FDT image\n");
+			return -ENOEXEC;
+		}
+		len = load_end - load;
+	} else if (load != data) {
+		loadbuf = map_sysmem(load, len);
+		memcpy(loadbuf, buf, len);
 	}
+
+	/* verify that image data is a proper FDT blob */
+	if (image_type == IH_TYPE_FLATDT && fdt_check_header(loadbuf)) {
+		puts("Subimage data is not a FDT");
+		return -ENOEXEC;
+	}
+
 	bootstage_mark(bootstage_id + BOOTSTAGE_SUB_LOAD);
 
-	*datap = data;
+	*datap = load;
 	*lenp = len;
 	if (fit_unamep)
 		*fit_unamep = (char *)fit_uname;
-- 
2.20.1