cmd: adtimg: Refactor usage style

Trying to extend 'adtimg' functionality [1], we've been severely hit
by a major limitation in the command's usage scheme. Specifically, the
command's user interface appears to be too centric to getting the
DTB/DTBO entry [3] based on the index of the desired DT in the image,
which makes it really difficult retrieving the DT entry based on
alternative criteria (e.g. filtering by id/rev fields), the
latter being demanded by real life customer use-cases [1].

This went to the point of receiving below feedback from Sam [2]:

 -- snip --
 As for 'dtimg' command: after giving it some thought, I think not much
 people using it yet. So in this particular case I don't have some
 strong preference, and if you think the 'dtimg' interface is ugly, and
 it overcomes "don't break interfaces" rule, maybe now is a good time
 to rework it (before it gets widely used).
 -- snip --

Given the above, rework the usage pattern from [4] to [5], in order to
allow an intuitive enablement of "by id|rev" DT search [6].

[1] https://patchwork.ozlabs.org/cover/1202575/
    ("cmd: dtimg: Enhance with --id and --rev options (take #1)")
[2] https://patchwork.ozlabs.org/patch/1182207/#2317020
[3] https://source.android.com/devices/architecture/dto/partitions
[4] Old usage
adtimg dump <addr>                    - Print image contents
adtimg start <addr> <index> <varname> - Get DT address by index
adtimg size <addr> <index> <varname>  - Get DT size by index

[5] New usage
adtimg addr <addr>                      - Set image location to <addr>
adtimg dump                             - Print out image contents
adtimg get dt --index=<i> [avar [svar]] - Get DT address and size by index

[6] Soon-to-be-provided "by id|rev" add-on functionality
adtimg get dt --id=<id> --rev=<rev> [avar [svar [ivar]]]
 - Get DT address/size/index by id|rev fields

Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>

1 files changed, 158 insertions, 59 deletions

diff --git a/cmd/adtimg.c b/cmd/adtimg.c
index 22b4f5e1a8..60bb01c349 100644
--- a/cmd/adtimg.c
+++ b/cmd/adtimg.c
@@ -2,18 +2,22 @@
 /*
  * (C) Copyright 2018 Linaro Ltd.
  * Sam Protsenko <semen.protsenko@linaro.org>
+ * Eugeniu Rosca <rosca.eugeniu@gmail.com>
  */
 
 #include <env.h>
 #include <image-android-dt.h>
 #include <common.h>
 
-enum cmd_adtimg_info {
-	CMD_ADTIMG_START = 0,
-	CMD_ADTIMG_SIZE,
-};
+#define OPT_INDEX	"--index"
 
-static int do_adtimg_dump(cmd_tbl_t *cmdtp, int flag, int argc,
+/*
+ * Current/working DTB/DTBO Android image address.
+ * Similar to 'working_fdt' variable in 'fdt' command.
+ */
+static ulong working_img;
+
+static int do_adtimg_addr(cmd_tbl_t *cmdtp, int flag, int argc,
 			  char * const argv[])
 {
 	char *endp;
@@ -24,86 +28,185 @@ static int do_adtimg_dump(cmd_tbl_t *cmdtp, int flag, int argc,
 
 	hdr_addr = simple_strtoul(argv[1], &endp, 16);
 	if (*endp != '\0') {
-		printf("Error: Wrong image address\n");
+		printf("Error: Wrong image address '%s'\n", argv[1]);
 		return CMD_RET_FAILURE;
 	}
 
-	if (!android_dt_check_header(hdr_addr)) {
-		printf("Error: DT image header is incorrect\n");
+	/*
+	 * Allow users to set an address prior to copying the DTB/DTBO
+	 * image to that same address, i.e. skip header verification.
+	 */
+
+	working_img = hdr_addr;
+	return CMD_RET_SUCCESS;
+}
+
+static int adtimg_check_working_img(void)
+{
+	if (!working_img) {
+		printf("Error: Please, call 'adtimg addr <addr>'. Aborting!\n");
 		return CMD_RET_FAILURE;
 	}
 
-	android_dt_print_contents(hdr_addr);
+	if (!android_dt_check_header(working_img)) {
+		printf("Error: Invalid image header at 0x%lx\n", working_img);
+		return CMD_RET_FAILURE;
+	}
 
 	return CMD_RET_SUCCESS;
 }
 
-static int adtimg_get_fdt(int argc, char * const argv[],
-			  enum cmd_adtimg_info cmd)
+static int do_adtimg_dump(cmd_tbl_t *cmdtp, int flag, int argc,
+			  char * const argv[])
 {
-	ulong hdr_addr;
-	u32 index;
-	char *endp;
-	ulong fdt_addr;
-	u32 fdt_size;
-	char buf[65];
-
-	if (argc != 4)
+	if (argc != 1)
 		return CMD_RET_USAGE;
 
-	hdr_addr = simple_strtoul(argv[1], &endp, 16);
-	if (*endp != '\0') {
-		printf("Error: Wrong image address\n");
+	if (adtimg_check_working_img() != CMD_RET_SUCCESS)
+		return CMD_RET_FAILURE;
+
+	android_dt_print_contents(working_img);
+
+	return CMD_RET_SUCCESS;
+}
+
+static int adtimg_getopt_u32(char * const opt, char * const name, u32 *optval)
+{
+	char *endp, *str;
+	u32 val;
+
+	if (!opt || !name || !optval)
+		return CMD_RET_FAILURE;
+
+	str = strchr(opt, '=');
+	if (!str) {
+		printf("Error: Option '%s' not followed by '='\n", name);
 		return CMD_RET_FAILURE;
 	}
 
-	if (!android_dt_check_header(hdr_addr)) {
-		printf("Error: DT image header is incorrect\n");
+	if (*++str == '\0') {
+		printf("Error: Option '%s=' not followed by value\n", name);
 		return CMD_RET_FAILURE;
 	}
 
-	index = simple_strtoul(argv[2], &endp, 0);
+	val = simple_strtoul(str, &endp, 0);
 	if (*endp != '\0') {
-		printf("Error: Wrong index\n");
+		printf("Error: Wrong integer value '%s=%s'\n", name, str);
 		return CMD_RET_FAILURE;
 	}
 
-	if (!android_dt_get_fdt_by_index(hdr_addr, index, &fdt_addr, &fdt_size))
+	*optval = val;
+	return CMD_RET_SUCCESS;
+}
+
+static int adtimg_getopt_index(int argc, char * const argv[], u32 *index,
+			       char **avar, char **svar)
+{
+	int ret;
+
+	if (!argv || !avar || !svar)
 		return CMD_RET_FAILURE;
 
-	switch (cmd) {
-	case CMD_ADTIMG_START:
-		snprintf(buf, sizeof(buf), "%lx", fdt_addr);
-		break;
-	case CMD_ADTIMG_SIZE:
-		snprintf(buf, sizeof(buf), "%x", fdt_size);
-		break;
-	default:
-		printf("Error: Unknown cmd_adtimg_info value: %d\n", cmd);
+	if (argc > 3) {
+		printf("Error: Unexpected argument '%s'\n", argv[3]);
 		return CMD_RET_FAILURE;
 	}
 
-	env_set(argv[3], buf);
+	ret = adtimg_getopt_u32(argv[0], OPT_INDEX, index);
+	if (ret != CMD_RET_SUCCESS)
+		return ret;
+
+	if (argc > 1)
+		*avar = argv[1];
+	if (argc > 2)
+		*svar = argv[2];
 
 	return CMD_RET_SUCCESS;
 }
 
-static int do_adtimg_start(cmd_tbl_t *cmdtp, int flag, int argc,
-			   char * const argv[])
+static int adtimg_get_dt_by_index(int argc, char * const argv[])
 {
-	return adtimg_get_fdt(argc, argv, CMD_ADTIMG_START);
+	ulong addr;
+	u32 index, size;
+	int ret;
+	char *avar = NULL, *svar = NULL;
+
+	ret = adtimg_getopt_index(argc, argv, &index, &avar, &svar);
+	if (ret != CMD_RET_SUCCESS)
+		return ret;
+
+	if (!android_dt_get_fdt_by_index(working_img, index, &addr, &size))
+		return CMD_RET_FAILURE;
+
+	if (avar && svar) {
+		ret = env_set_hex(avar, addr);
+		if (ret) {
+			printf("Error: Can't set '%s' to 0x%lx\n", avar, addr);
+			return CMD_RET_FAILURE;
+		}
+		ret = env_set_hex(svar, size);
+		if (ret) {
+			printf("Error: Can't set '%s' to 0x%x\n", svar, size);
+			return CMD_RET_FAILURE;
+		}
+	} else if (avar) {
+		ret = env_set_hex(avar, addr);
+		if (ret) {
+			printf("Error: Can't set '%s' to 0x%lx\n", avar, addr);
+			return CMD_RET_FAILURE;
+		}
+		printf("0x%x (%d)\n", size, size);
+	} else {
+		printf("0x%lx, 0x%x (%d)\n", addr, size, size);
+	}
+
+	return CMD_RET_SUCCESS;
 }
 
-static int do_adtimg_size(cmd_tbl_t *cmdtp, int flag, int argc,
-			  char * const argv[])
+static int adtimg_get_dt(int argc, char * const argv[])
 {
-	return adtimg_get_fdt(argc, argv, CMD_ADTIMG_SIZE);
+	if (argc < 2) {
+		printf("Error: No options passed to '%s'\n", argv[0]);
+		return CMD_RET_FAILURE;
+	}
+
+	/* Strip off leading 'dt' command argument */
+	argc--;
+	argv++;
+
+	if (!strncmp(argv[0], OPT_INDEX, sizeof(OPT_INDEX) - 1))
+		return adtimg_get_dt_by_index(argc, argv);
+
+	printf("Error: Option '%s' not supported\n", argv[0]);
+	return CMD_RET_FAILURE;
+}
+
+static int do_adtimg_get(cmd_tbl_t *cmdtp, int flag, int argc,
+			 char * const argv[])
+{
+	if (argc < 2) {
+		printf("Error: No arguments passed to '%s'\n", argv[0]);
+		return CMD_RET_FAILURE;
+	}
+
+	if (adtimg_check_working_img() != CMD_RET_SUCCESS)
+		return CMD_RET_FAILURE;
+
+	/* Strip off leading 'get' command argument */
+	argc--;
+	argv++;
+
+	if (!strcmp(argv[0], "dt"))
+		return adtimg_get_dt(argc, argv);
+
+	printf("Error: Wrong argument '%s'\n", argv[0]);
+	return CMD_RET_FAILURE;
 }
 
 static cmd_tbl_t cmd_adtimg_sub[] = {
-	U_BOOT_CMD_MKENT(dump, 2, 0, do_adtimg_dump, "", ""),
-	U_BOOT_CMD_MKENT(start, 4, 0, do_adtimg_start, "", ""),
-	U_BOOT_CMD_MKENT(size, 4, 0, do_adtimg_size, "", ""),
+	U_BOOT_CMD_MKENT(addr, CONFIG_SYS_MAXARGS, 1, do_adtimg_addr, "", ""),
+	U_BOOT_CMD_MKENT(dump, CONFIG_SYS_MAXARGS, 1, do_adtimg_dump, "", ""),
+	U_BOOT_CMD_MKENT(get, CONFIG_SYS_MAXARGS, 1, do_adtimg_get, "", ""),
 };
 
 static int do_adtimg(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
@@ -127,17 +230,13 @@ static int do_adtimg(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 U_BOOT_CMD(
 	adtimg, CONFIG_SYS_MAXARGS, 0, do_adtimg,
 	"manipulate dtb/dtbo Android image",
-	"dump <addr>\n"
-	"    - parse specified image and print its structure info\n"
-	"      <addr>: image address in RAM, in hex\n"
-	"adtimg start <addr> <index> <varname>\n"
-	"    - get address (hex) 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 address of FDT\n"
-	"adtimg size <addr> <index> <varname>\n"
-	"    - 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"
+	"addr <addr> - Set image location to <addr>\n"
+	"adtimg dump        - Print out image contents\n"
+	"adtimg get dt --index=<index> [avar [svar]]         - Get DT address/size by index\n"
+	"\n"
+	"Legend:\n"
+	"  - <addr>: DTB/DTBO image address (hex) in RAM\n"
+	"  - <index>: index (hex/dec) of desired DT in the image\n"
+	"  - <avar>: variable name to contain DT address (hex)\n"
+	"  - <svar>: variable name to contain DT size (hex)"
 );