cgpt: add support for managing GPT platform required partition bit

Bit 0 in the GPT partition attributes is defined to indicate whether a
partition is required by the platform. This CL adds the support for
managing this bit to cgpt.

BUG=b:70807006
BRANCH=None
TEST=Run unit tests.

Change-Id: Iaf87c828438b3df6730de502ae420fcf4c61277b
Reviewed-on: https://chromium-review.googlesource.com/902196
Commit-Ready: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

6 files changed, 39 insertions, 4 deletions

diff --git a/cgpt/cgpt.h b/cgpt/cgpt.h
index 1216a72c..86f4b851 100644
--- a/cgpt/cgpt.h
+++ b/cgpt/cgpt.h
@@ -149,6 +149,9 @@ void EntryDetails(GptEntry *entry, uint32_t index, int raw);
 uint32_t GetNumberOfEntries(const struct drive *drive);
 GptEntry *GetEntry(GptData *gpt, int secondary, uint32_t entry_index);
 
+void SetRequired(struct drive *drive, int secondary, uint32_t entry_index,
+                 int required);
+int GetRequired(struct drive *drive, int secondary, uint32_t entry_index);
 void SetLegacyBoot(struct drive *drive, int secondary, uint32_t entry_index,
                    int legacy_boot);
 int GetLegacyBoot(struct drive *drive, int secondary, uint32_t entry_index);
diff --git a/cgpt/cgpt_add.c b/cgpt/cgpt_add.c
index 5ac50677..c0e93f3d 100644
--- a/cgpt/cgpt_add.c
+++ b/cgpt/cgpt_add.c
@@ -53,6 +53,10 @@ static const char* DumpCgptAddParams(const CgptAddParams *params) {
     snprintf(tmp, sizeof(tmp), "-P %d ", params->priority);
     StrnAppend(buf, tmp, sizeof(buf));
   }
+  if (params->set_required) {
+    snprintf(tmp, sizeof(tmp), "-R %d ", params->required);
+    StrnAppend(buf, tmp, sizeof(buf));
+  }
   if (params->set_legacy_boot) {
     snprintf(tmp, sizeof(tmp), "-B %d ", params->legacy_boot);
     StrnAppend(buf, tmp, sizeof(buf));
@@ -113,6 +117,8 @@ static int SetEntryAttributes(struct drive *drive,
       SetPriority(drive, PRIMARY, index, params->priority);
     if (params->set_legacy_boot)
       SetLegacyBoot(drive, PRIMARY, index, params->legacy_boot);
+    if (params->set_required)
+      SetRequired(drive, PRIMARY, index, params->required);
   }
 
   // New partitions must specify type, begin, and size.
diff --git a/cgpt/cgpt_common.c b/cgpt/cgpt_common.c
index 1a6bd3cb..f6108c1e 100644
--- a/cgpt/cgpt_common.c
+++ b/cgpt/cgpt_common.c
@@ -763,6 +763,20 @@ GptEntry *GetEntry(GptData *gpt, int secondary, uint32_t entry_index) {
   return (GptEntry*)(&entries[stride * entry_index]);
 }
 
+void SetRequired(struct drive *drive, int secondary, uint32_t entry_index,
+                 int required) {
+  require(required >= 0 && required <= CGPT_ATTRIBUTE_MAX_REQUIRED);
+  GptEntry *entry;
+  entry = GetEntry(&drive->gpt, secondary, entry_index);
+  SetEntryRequired(entry, required);
+}
+
+int GetRequired(struct drive *drive, int secondary, uint32_t entry_index) {
+  GptEntry *entry;
+  entry = GetEntry(&drive->gpt, secondary, entry_index);
+  return GetEntryRequired(entry);
+}
+
 void SetLegacyBoot(struct drive *drive, int secondary, uint32_t entry_index,
                    int legacy_boot) {
   require(legacy_boot >= 0 && legacy_boot <= CGPT_ATTRIBUTE_MAX_LEGACY_BOOT);
diff --git a/cgpt/cgpt_show.c b/cgpt/cgpt_show.c
index cd4a6136..60d73ec7 100644
--- a/cgpt/cgpt_show.c
+++ b/cgpt/cgpt_show.c
@@ -136,9 +136,9 @@ void EntryDetails(GptEntry *entry, uint32_t index, int raw) {
                       priority, tries, successful);
     }
 
-    if (entry->attrs.fields.system) {
+    if (entry->attrs.fields.required) {
       clen += snprintf(contents + clen, sizeof(contents) - clen,
-                       "system=%d ", entry->attrs.fields.system);
+                       "required=%d ", entry->attrs.fields.required);
       require(clen < sizeof(contents));
     }
 
@@ -230,6 +230,9 @@ static int GptShow(struct drive *drive, CgptShowParams *params) {
       case 'P':
         printf("%d\n", GetPriority(drive, ANY_VALID, index));
         break;
+      case 'R':
+        printf("%d\n", GetRequired(drive, ANY_VALID, index));
+        break;
       case 'B':
         printf("%d\n", GetLegacyBoot(drive, ANY_VALID, index));
         break;
diff --git a/cgpt/cmd_add.c b/cgpt/cmd_add.c
index 3c7741b8..f10489ac 100644
--- a/cgpt/cmd_add.c
+++ b/cgpt/cmd_add.c
@@ -27,6 +27,7 @@ static void Usage(void)
          "  -S NUM       set Successful flag (0|1)\n"
          "  -T NUM       set Tries flag (0-15)\n"
          "  -P NUM       set Priority flag (0-15)\n"
+         "  -R NUM       set Required flag (0|1)\n"
          "  -B NUM       set Legacy Boot flag (0|1)\n"
          "  -A NUM       set raw 16-bit attribute value (bits 48-63)\n"
          "\n"
@@ -46,7 +47,7 @@ int cmd_add(int argc, char *argv[]) {
   char *e = 0;
 
   opterr = 0;                     // quiet, you
-  while ((c=getopt(argc, argv, ":hi:b:s:t:u:l:S:T:P:B:A:D:")) != -1)
+  while ((c=getopt(argc, argv, ":hi:b:s:t:u:l:S:T:P:R:B:A:D:")) != -1)
   {
     switch (c)
     {
@@ -104,6 +105,12 @@ int cmd_add(int argc, char *argv[]) {
       errorcnt += check_int_parse(c, e);
       errorcnt += check_int_limit(c, params.priority, 0, 15);
       break;
+    case 'R':
+      params.set_required = 1;
+      params.required = (uint32_t)strtoul(optarg, &e, 0);
+      errorcnt += check_int_parse(c, e);
+      errorcnt += check_int_limit(c, params.required, 0, 1);
+      break;
     case 'B':
       params.set_legacy_boot = 1;
       params.legacy_boot = (uint32_t)strtoul(optarg, &e, 0);
diff --git a/cgpt/cmd_show.c b/cgpt/cmd_show.c
index b9e64818..6f31b3b5 100644
--- a/cgpt/cmd_show.c
+++ b/cgpt/cmd_show.c
@@ -32,6 +32,7 @@ static void Usage(void)
          "               -S  Successful flag\n"
          "               -T  Tries flag\n"
          "               -P  Priority flag\n"
+         "               -R  Required flag\n"
          "               -B  Legacy Boot flag\n"
          "               -A  raw 16-bit attribute value (bits 48-63)\n"
          "  -d           Debug output (including invalid headers)\n"
@@ -47,7 +48,7 @@ int cmd_show(int argc, char *argv[]) {
   char *e = 0;
 
   opterr = 0;                     // quiet, you
-  while ((c=getopt(argc, argv, ":hnvqi:bstulSTPBAdD:")) != -1)
+  while ((c=getopt(argc, argv, ":hnvqi:bstulSTPRBAdD:")) != -1)
   {
     switch (c)
     {
@@ -76,6 +77,7 @@ int cmd_show(int argc, char *argv[]) {
     case 'S':
     case 'T':
     case 'P':
+    case 'R':
     case 'B':
     case 'A':
       params.single_item = c;