cmd: dtimg: get devicetree index based on board identifier and revision

The dtimg includes several devicetrees selected by an index.
Each device tree is added in the dtimg associated with a board identifier
(and optionally a board revision).

This service is added to get back the index associated to the board id
and optionally the board rev.

Change-Id: Ie7670d4a9ee132953296a8616ce5575b6fa65de4
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/u-boot/+/135279
Reviewed-by: CITOOLS <smet-aci-reviews@lists.codex.cro.st.com>
Reviewed-by: CIBUILD <smet-aci-builds@lists.codex.cro.st.com>
Reviewed-by: Patrick DELAUNAY <patrick.delaunay@st.com>
Tested-by: Patrick DELAUNAY <patrick.delaunay@st.com>

cmd/dtimg.c

@@ -99,10 +99,52 @@ static int do_dtimg_size(cmd_tbl_t *cmdtp, int flag, int argc,
 	return dtimg_get_fdt(argc, argv, CMD_DTIMG_SIZE);
 }
 
+static int do_dtimg_getindex(cmd_tbl_t *cmdtp, int flag, int argc,
+			     char * const argv[])
+{
+	char *endp;
+	ulong hdr_addr;
+	int index;
+	char buf[512] = { 0 };
+
+	if (argc < 4)
+		return CMD_RET_USAGE;
+
+	hdr_addr = simple_strtoul(argv[1], &endp, 16);
+	if (*endp != '\0') {
+		printf("Error: Wrong image address\n");
+		return CMD_RET_FAILURE;
+	}
+
+	if (!android_dt_check_header(hdr_addr)) {
+		printf("Error: DT image header is incorrect\n");
+		return CMD_RET_FAILURE;
+	}
+
+	index = android_dt_get_index(hdr_addr, strtoul(argv[2], NULL, 0),
+				     strtoul(argv[3], NULL, 0));
+
+	if (index < 0) {
+		printf("Error: board id %04lx not found in DT table\n",
+		       strtoul(argv[2], NULL, 0));
+		return CMD_RET_FAILURE;
+	}
+
+	snprintf(buf, sizeof(buf), "%i", index);
+
+	if (argc == 5)
+		env_set(argv[4], buf);
+	else
+		printf("%s\n", buf);
+
+	return CMD_RET_SUCCESS;
+}
+
 static cmd_tbl_t cmd_dtimg_sub[] = {
 	U_BOOT_CMD_MKENT(dump, 2, 0, do_dtimg_dump, "", ""),
 	U_BOOT_CMD_MKENT(start, 4, 0, do_dtimg_start, "", ""),
 	U_BOOT_CMD_MKENT(size, 4, 0, do_dtimg_size, "", ""),
+	U_BOOT_CMD_MKENT(getindex, 5, 0, do_dtimg_getindex, "", ""),
 };
 
 static int do_dtimg(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
@@ -138,5 +180,11 @@ U_BOOT_CMD(
 	"    - get size (hex, bytes) of FDT in the image, by index\n"
 	"      <addr>: image address in RAM, in hex\n"
 	"      <index>: index of desired FDT in the image\n"
-	"      <varname>: name of variable where to store size of FDT"
+	"      <varname>: name of variable where to store size of FDT\n"
+	"dtimg getindex <addr> <board_id> <board_rev> [varname]\n"
+	"    - get index of FDT in the image, by board identifier and revision\n"
+	"      <addr>: image address in RAM, in hex\n"
+	"      <board_id>: board identifier\n"
+	"      <board_rev>: board revision (0 if not used)\n"
+	"      [varname]: name of variable where to store index of FDT"
 );

common/image-android-dt.c

@@ -154,4 +154,46 @@ void android_dt_print_contents(ulong hdr_addr)
 		unmap_sysmem(fdt);
 	}
 }
+
 #endif
+
+/**
+ * Get dtb index based on board identifier and revision.
+ *
+ * @param hdr_addr Start address of DT image
+ * @param board_id board identifier
+ * @param board_rev board revision (0 if not used)
+ *
+ * @return index in dt table
+ */
+int android_dt_get_index(ulong hdr_addr, u32 board_id, u32 board_rev)
+{
+	const struct dt_table_header *hdr;
+	u32 entry_count, entries_offset, entry_size;
+	u32 i;
+	int ret = -1;
+
+	hdr = map_sysmem(hdr_addr, sizeof(*hdr));
+	entry_count = fdt32_to_cpu(hdr->dt_entry_count);
+	entries_offset = fdt32_to_cpu(hdr->dt_entries_offset);
+	entry_size = fdt32_to_cpu(hdr->dt_entry_size);
+	unmap_sysmem(hdr);
+
+	for (i = 0; i < entry_count; ++i) {
+		const ulong e_addr = hdr_addr + entries_offset + i * entry_size;
+		const struct dt_table_entry *e;
+
+		e = map_sysmem(e_addr, sizeof(*e));
+
+		if ((fdt32_to_cpu(e->id) == board_id) &&
+		    (board_rev == 0 || fdt32_to_cpu(e->rev) == board_rev)) {
+			ret = i;
+			unmap_sysmem(e);
+			break;
+		}
+
+		unmap_sysmem(e);
+	}
+
+	return ret;
+}

include/image-android-dt.h

@@ -17,4 +17,6 @@ bool android_dt_get_fdt_by_index(ulong hdr_addr, u32 index, ulong *addr,
 void android_dt_print_contents(ulong hdr_addr);
 #endif
 
+int android_dt_get_index(ulong hdr_addr, u32 board_id, u32 board_rev);
+
 #endif /* IMAGE_ANDROID_DT_H */