[PATCH v2 3/4] Do NULL memory quirk workaround only when explicitly requested

[Vladimir Serbinenko]

It's only needed for DragonFlyBSD and breaks OpenBSD bsd.mp variant

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
---
 grub-core/loader/i386/bsd.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/grub-core/loader/i386/bsd.c b/grub-core/loader/i386/bsd.c
index 58b976861..af2b7cb9a 100644
--- a/grub-core/loader/i386/bsd.c
+++ b/grub-core/loader/i386/bsd.c
@@ -71,6 +71,7 @@ GRUB_MOD_LICENSE ("GPLv3+");
 #define ALIGN_PAGE(a)  ALIGN_UP (a, 4096)
 
 static int kernel_type = KERNEL_TYPE_NONE;
+static int do_null_quirk;
 static grub_dl_t my_mod;
 static grub_addr_t entry, entry_hi, kern_start, kern_end;
 static void *kern_chunk_src;
@@ -123,16 +124,19 @@ static const struct grub_arg_option freebsd_opts[] =
     {"dfltroot", 'r', 0, N_("Use compiled-in root device."), 0, 0},
     {"single", 's', 0, N_("Boot into single mode."), 0, 0},
     {"verbose", 'v', 0, N_("Boot with verbose messages."), 0, 0},
+    {"null-quirk", 0, 0, N_("Workaround NULL bug that prevents DragonFlyBSD to 
boot with coreboot"), 0, 0},
     {0, 0, 0, 0, 0, 0}
   };
 
+#define FREEBSD_NULL_QUIRK_FLAG 14
+
 static const grub_uint32_t freebsd_flags[] =
 {
   FREEBSD_RB_DUAL, FREEBSD_RB_SERIAL, FREEBSD_RB_ASKNAME,
   FREEBSD_RB_CDROM, FREEBSD_RB_CONFIG, FREEBSD_RB_KDB,
   FREEBSD_RB_GDB, FREEBSD_RB_MUTE, FREEBSD_RB_NOINTR,
   FREEBSD_RB_PAUSE, FREEBSD_RB_QUIET, FREEBSD_RB_DFLTROOT,
-  FREEBSD_RB_SINGLE, FREEBSD_RB_VERBOSE, 0
+  FREEBSD_RB_SINGLE, FREEBSD_RB_VERBOSE, 0, 0
 };
 
 static const struct grub_arg_option openbsd_opts[] =
@@ -326,8 +330,8 @@ generate_e820_mmap_iter (grub_uint64_t addr, grub_uint64_t 
size,
   ctx->cur.addr = addr;
   ctx->cur.size = size;
 
-  if (type == GRUB_MEMORY_COREBOOT_TABLES
-      && addr == 0)
+   if (type == GRUB_MEMORY_COREBOOT_TABLES
+       && addr == 0 && do_null_quirk)
       /* Nowadays the tables at 0 don't contain anything important but
        *BSD needs the memory at 0 for own needs.
        */
@@ -925,7 +929,7 @@ grub_freebsd_boot (void)
         DragonFlyBSD needs the memory at 0 for own needs.
        */
       if (efi_mmap_size_out >= sizeof(grub_efi_memory_descriptor_t) && 
efidescs->physical_start == 0
-         && efidescs->type == GRUB_EFI_RESERVED_MEMORY_TYPE && 
efidescs->num_pages <= (grub_coreboot_get_zerotables_size() >> 
GRUB_EFI_PAGE_SHIFT))
+         && efidescs->type == GRUB_EFI_RESERVED_MEMORY_TYPE && do_null_quirk 
&& efidescs->num_pages <= (grub_coreboot_get_zerotables_size() >> 
GRUB_EFI_PAGE_SHIFT))
        {
          efidescs->type = GRUB_EFI_CONVENTIONAL_MEMORY;
        }
@@ -1851,6 +1855,7 @@ grub_cmd_freebsd (grub_extcmd_context_t ctxt, int argc, 
char *argv[])
 {
   kernel_type = KERNEL_TYPE_FREEBSD;
   bootflags = grub_bsd_parse_flags (ctxt->state, freebsd_flags);
+  do_null_quirk = ctxt->state[FREEBSD_NULL_QUIRK_FLAG].set;
 
   if (grub_bsd_load (argc, argv) == GRUB_ERR_NONE)
     {
@@ -1931,6 +1936,7 @@ grub_cmd_openbsd (grub_extcmd_context_t ctxt, int argc, 
char *argv[])
 
   kernel_type = KERNEL_TYPE_OPENBSD;
   bootflags = grub_bsd_parse_flags (ctxt->state, openbsd_flags);
+  do_null_quirk = 0;
 
   if (ctxt->state[OPENBSD_ROOT_ARG].set && ctxt->state[OPENBSD_ROOT_ARG].arg 
!= NULL)
     {
@@ -2025,6 +2031,7 @@ grub_cmd_netbsd (grub_extcmd_context_t ctxt, int argc, 
char *argv[])
   grub_err_t err;
   kernel_type = KERNEL_TYPE_NETBSD;
   bootflags = grub_bsd_parse_flags (ctxt->state, netbsd_flags);
+  do_null_quirk = 0;
 
   if (grub_bsd_load (argc, argv) == GRUB_ERR_NONE)
     {
-- 
2.39.2