Create add_partition() and use in GPT_init() to initialize GPT

with EFI SYS and OpenBSD partitions. Replaces some barbarian
direct whacking of GPT.

ok kettenis@

diff --git a/sbin/fdisk/gpt.c b/sbin/fdisk/gpt.c
index 77df948..434071b 100644 (file)
--- a/sbin/fdisk/gpt.c
+++ b/sbin/fdisk/gpt.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: gpt.c,v 1.21 2021/06/12 00:47:29 krw Exp $    */
+/*     $OpenBSD: gpt.c,v 1.22 2021/06/12 14:10:01 krw Exp $    */
 /*
  * Copyright (c) 2015 Markus Muller <mmu@grummel.net>
  * Copyright (c) 2015 Kenneth R Westerback <krw@openbsd.org>
@@ -45,6 +45,7 @@ struct gpt_partition gp[NGPTPARTITIONS];
 struct gpt_partition   **sort_gpt(void);
 int                      lba_start_cmp(const void *e1, const void *e2);
 int                      lba_free(uint64_t *, uint64_t *);
+int                      add_partition(const uint8_t *, const char *, uint64_t);
 
 int
 GPT_get_header(off_t where)
@@ -302,13 +303,74 @@ GPT_print_part(int n, char *units, int verbosity)
        }
 }
 
+int
+add_partition(const uint8_t *beuuid, const char *name, uint64_t sectors)
+{
+       struct uuid uuid, gp_type;
+       int rslt;
+       uint64_t end, freesectors, start;
+       uint32_t status, pn, pncnt;
+
+       uuid_dec_be(beuuid, &uuid);
+       uuid_enc_le(&gp_type, &uuid);
+
+       pncnt = letoh32(gh.gh_part_num);
+       for (pn = 0; pn < pncnt; pn++) {
+               if (uuid_is_nil(&gp[pn].gp_type, NULL))
+                       break;
+       }
+       if (pn == pncnt)
+               goto done;
+
+       rslt = lba_free(&start, &end);
+       if (rslt == -1)
+               goto done;
+
+       if (start % 64)
+               start += (64 - start % 64);
+       if (start >= end)
+               goto done;
+
+       freesectors = end - start + 1;
+
+       if (sectors == 0)
+               sectors = freesectors;
+
+       if (freesectors < sectors)
+               goto done;
+       else if (freesectors > sectors)
+               end = start + sectors - 1;
+
+       gp[pn].gp_type = gp_type;
+       gp[pn].gp_lba_start = htole64(start);
+       gp[pn].gp_lba_end = htole64(end);
+       memcpy(gp[pn].gp_name, string_to_utf16le(name),
+           sizeof(gp[pn].gp_name));
+
+       uuid_create(&uuid, &status);
+       if (status != uuid_s_ok)
+               goto done;
+
+       uuid_enc_le(&gp[pn].gp_guid, &uuid);
+       gh.gh_part_csum = crc32((unsigned char *)&gp, sizeof(gp));
+       gh.gh_csum = crc32((unsigned char *)&gh, sizeof(gh));
+
+       return 0;
+
+ done:
+       if (pn != pncnt)
+               memset(&gp[pn], 0, sizeof(gp[pn]));
+       printf("unable to add %s\n", name);
+       return 1;
+}
+
 int
 GPT_init(void)
 {
        extern uint32_t b_arg;
        const int secsize = unit_types[SECTORS].conversion;
        struct uuid guid;
-       int needed;
+       int needed, rslt;
        uint32_t status;
        const uint8_t gpt_uuid_efi_system[] = GPT_UUID_EFI_SYSTEM;
        const uint8_t gpt_uuid_openbsd[] = GPT_UUID_OPENBSD;
@@ -339,46 +401,17 @@ GPT_init(void)
                return (1);
        uuid_enc_le(&gh.gh_guid, &guid);
 
+       rslt = 0;
 #if defined(__i386__) || defined(__amd64__)
        if (b_arg > 0) {
-               /* Add an EFI system partition on i386/amd64. */
-               uuid_dec_be(gpt_uuid_efi_system, &guid);
-               uuid_enc_le(&gp[1].gp_type, &guid);
-               uuid_create(&guid, &status);
-               if (status != uuid_s_ok)
-                       return (1);
-               uuid_enc_le(&gp[1].gp_guid, &guid);
-               gp[1].gp_lba_start = gh.gh_lba_start;
-               gp[1].gp_lba_end = htole64(letoh64(gh.gh_lba_start)+b_arg - 1);
-               memcpy(gp[1].gp_name, string_to_utf16le("EFI System Area"),
-                   sizeof(gp[1].gp_name));
-       }
-#endif
-       uuid_dec_be(gpt_uuid_openbsd, &guid);
-       uuid_enc_le(&gp[3].gp_type, &guid);
-       uuid_create(&guid, &status);
-       if (status != uuid_s_ok)
-               return (1);
-       uuid_enc_le(&gp[3].gp_guid, &guid);
-       gp[3].gp_lba_start = gh.gh_lba_start;
-#if defined(__i386__) || defined(__amd64__)
-       if (b_arg > 0) {
-               gp[3].gp_lba_start = htole64(letoh64(gp[3].gp_lba_start) +
+               rslt = add_partition(gpt_uuid_efi_system, "EFI System Area",
                    b_arg);
-               if (letoh64(gp[3].gp_lba_start) % 64)
-                       gp[3].gp_lba_start =
-                           htole64(letoh64(gp[3].gp_lba_start) +
-                           (64 - letoh64(gp[3].gp_lba_start) % 64));
        }
 #endif
-       gp[3].gp_lba_end = gh.gh_lba_end;
-       memcpy(gp[3].gp_name, string_to_utf16le("OpenBSD Area"),
-           sizeof(gp[3].gp_name));
+       if (rslt == 0)
+               rslt = add_partition(gpt_uuid_openbsd, "OpenBSD Area", 0);
 
-       gh.gh_part_csum = crc32((unsigned char *)&gp, sizeof(gp));
-       gh.gh_csum = crc32((unsigned char *)&gh, sizeof(gh));
-
-       return 0;
+       return rslt;
 }
 
 int