[PATCH v2 3/3] discover/grub: Allow to set a default index for BLS entries

[Javier Martinez Canillas]

When the BLS support was added, the conclusion was that default indexes
didn't apply for BLS snippets. But for GRUB 2 the indexes refers to the
boot menu entries in memory, regardless of how these were generated.

Since in GRUB 2 is valid to set a default index even for menu entries
generated from BLS fragments, allow this to also be done in Petitboot.

Signed-off-by: Javier Martinez Canillas <javierm at redhat.com>

---

Changes in v2:
- Simplify expression when checking for default index.
- Don't start the index for BLS entries from 0 since can be mixed with
  menu entries in the grub config file.
- Add menu entries in grub config for grub2-blscfg-default-index test.

 discover/grub2/blscfg.c                       | 17 +++++++---
 test/parser/Makefile.am                       |  1 +
 test/parser/test-grub2-blscfg-default-index.c | 45 +++++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 4 deletions(-)
 create mode 100644 test/parser/test-grub2-blscfg-default-index.c

diff --git a/discover/grub2/blscfg.c b/discover/grub2/blscfg.c
index 5dadd2c6e8ef..a1076b9db27b 100644
--- a/discover/grub2/blscfg.c
+++ b/discover/grub2/blscfg.c
@@ -20,6 +20,7 @@
 struct bls_state {
 	struct discover_boot_option *opt;
 	struct grub2_script *script;
+	unsigned int idx;
 	const char *filename;
 	const char *title;
 	const char *version;
@@ -81,19 +82,25 @@ static void bls_process_pair(struct conf_context *conf, const char *name,
 	}
 }
 
-static bool option_is_default(struct grub2_script *script,
+static bool option_is_default(struct bls_state *state,
 			      struct boot_option *option)
 {
+	unsigned int idx;
 	const char *var;
+	char *end;
 
-	var = script_env_get(script, "default");
+	var = script_env_get(state->script, "default");
 	if (!var)
 		return false;
 
 	if (!strcmp(var, option->id))
 		return true;
 
-	return !strcmp(var, option->name);
+	if (!strcmp(var, option->name))
+		return true;
+
+	idx = strtoul(var, &end, 10);
+	return end != var && *end == '\0' && idx == state->idx;
 }
 
 static void bls_finish(struct conf_context *conf)
@@ -141,7 +148,7 @@ static void bls_finish(struct conf_context *conf)
 		opt->dtb = create_grub2_resource(opt, conf->dc->device,
 						 root, state->dtb);
 
-	option->is_default = option_is_default(state->script, option);
+	option->is_default = option_is_default(state, option);
 
 	list_add_tail(&state->script->options, &opt->list);
 	state->script->n_options++;
@@ -176,6 +183,7 @@ int builtin_blscfg(struct grub2_script *script,
 		int argc __attribute__((unused)),
 		char *argv[] __attribute__((unused)))
 {
+	unsigned int current_idx = script->n_options;
 	struct discover_context *dc = script->ctx;
 	struct dirent **bls_entries;
 	struct conf_context *conf;
@@ -217,6 +225,7 @@ int builtin_blscfg(struct grub2_script *script,
 
 		state->script = script;
 		state->filename = filename;
+		state->idx = current_idx++;
 		conf->parser_info = state;
 
 		rc = parser_request_file(dc, dc->device, filename, &buf, &len);
diff --git a/test/parser/Makefile.am b/test/parser/Makefile.am
index 3479d88cdb23..6ff3972d8316 100644
--- a/test/parser/Makefile.am
+++ b/test/parser/Makefile.am
@@ -41,6 +41,7 @@ parser_TESTS = \
 	test/parser/test-grub2-test-file-ops \
 	test/parser/test-grub2-single-yocto \
 	test/parser/test-grub2-blscfg-default-filename \
+	test/parser/test-grub2-blscfg-default-index \
 	test/parser/test-grub2-blscfg-default-title \
 	test/parser/test-grub2-blscfg-multiple-bls \
 	test/parser/test-grub2-blscfg-opts-config \
diff --git a/test/parser/test-grub2-blscfg-default-index.c b/test/parser/test-grub2-blscfg-default-index.c
new file mode 100644
index 000000000000..4ef3e2e68bcc
--- /dev/null
+++ b/test/parser/test-grub2-blscfg-default-index.c
@@ -0,0 +1,45 @@
+#include "parser-test.h"
+
+#if 0 /* PARSER_EMBEDDED_CONFIG */
+set default=2
+menuentry 'title Fedora (4.15-9-304.fc28.x86_64) 28 (Twenty Eight)' {
+	linux   /vmlinuz-4.15-9-301.fc28.x86_64
+}
+
+menuentry 'title Fedora (4.15.6-300.fc28.x86_64) 28 (Twenty Eight)' {
+	linux   /vmlinuz-4.15.6-300.fc28.x86_64
+}
+blscfg
+#endif
+
+void run_test(struct parser_test *test)
+{
+	struct discover_boot_option *opt;
+	struct discover_context *ctx;
+
+	test_add_file_string(test, test->ctx->device,
+			     "/loader/entries/6c063c8e48904f2684abde8eea303f41-4.15.2-300.fc28.x86_64.conf",
+			     "title Fedora (4.15.2-300.fc28.x86_64) 28 (Twenty Eight)\n"
+			     "linux /vmlinuz-4.15.2-300.fc28.x86_64\n"
+			     "initrd /initramfs-4.15.2-300.fc28.x86_64.img\n"
+			     "options root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root\n\n");
+
+	test_add_file_string(test, test->ctx->device,
+			     "/loader/entries/6c063c8e48904f2684abde8eea303f41-4.14.18-300.fc28.x86_64.conf",
+			     "title Fedora (4.14.18-300.fc28.x86_64) 28 (Twenty Eight)\n"
+			     "linux /vmlinuz-4.14.18-300.fc28.x86_64\n"
+			     "initrd /initramfs-4.14.18-300.fc28.x86_64.img\n"
+			     "options root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root\n");
+
+	test_read_conf_embedded(test, "/boot/grub2/grub.cfg");
+
+	test_run_parser(test, "grub2");
+
+	ctx = test->ctx;
+
+	opt = get_boot_option(ctx, 2);
+
+	check_name(opt, "Fedora (4.15.2-300.fc28.x86_64) 28 (Twenty Eight)");
+
+	check_is_default(opt);
+}
-- 
2.16.2