Re: booting kernel of NetBSD (Re: UFS (FFS) support seems broken in grub2)

[Bean]

this is the patch, problems found:

1, the mbi structure is not initialized to all zeros, this means some
important member, like mods_count, will contain trash.
2, the entry point in the header is virtual address, we need to
translate it to physical address.

        * loader/i386/pc/multiboot.c (grub_multiboot_load_elf32): Get physical
        address of entry.
        (grub_multiboot_load_elf64): Likewise.
        (grub_multiboot): Initialize mbi structure.


diff --git a/loader/i386/pc/multiboot.c b/loader/i386/pc/multiboot.c
index fa6346e..2fd2b24 100644
--- a/loader/i386/pc/multiboot.c
+++ b/loader/i386/pc/multiboot.c
@@ -96,6 +96,7 @@ grub_multiboot_load_elf32 (grub_file_t file, void *buffer)
 {
   Elf32_Ehdr *ehdr = (Elf32_Ehdr *) buffer;
   Elf32_Phdr *phdr;
+  grub_addr_t real_entry = 0;
   int i;

   if (ehdr->e_ident[EI_CLASS] != ELFCLASS32)
@@ -144,9 +145,16 @@ grub_multiboot_load_elf32 (grub_file_t file, void *buffer)
           if (phdr->p_filesz < phdr->p_memsz)
             grub_memset ((char *) phdr->p_paddr + phdr->p_filesz, 0,
                         phdr->p_memsz - phdr->p_filesz);
+
+          if ((entry >= phdr->p_vaddr) &&
+             (entry < phdr->p_vaddr + phdr->p_memsz))
+           real_entry = entry + phdr->p_paddr - phdr->p_vaddr;
         }
     }
-
+
+  if (real_entry)
+    entry = real_entry;
+
   return grub_errno;
 }

@@ -164,6 +172,7 @@ grub_multiboot_load_elf64 (grub_file_t file, void *buffer)
 {
   Elf64_Ehdr *ehdr = (Elf64_Ehdr *) buffer;
   Elf64_Phdr *phdr;
+  grub_addr_t real_entry = 0;
   int i;

   if (ehdr->e_ident[EI_CLASS] != ELFCLASS64)
@@ -226,9 +235,16 @@ grub_multiboot_load_elf64 (grub_file_t file, void *buffer)
                          + phdr->p_filesz),
                         0,
                         phdr->p_memsz - phdr->p_filesz);
+
+         if ((entry >= phdr->p_vaddr) &&
+             (entry < phdr->p_vaddr + phdr->p_memsz))
+           real_entry = entry + phdr->p_paddr - phdr->p_vaddr;
         }
     }
-
+
+  if (real_entry)
+    entry = real_entry;
+
   return grub_errno;
 }

@@ -306,6 +322,8 @@ grub_multiboot (int argc, char *argv[])
   if (! mbi)
     goto fail;

+  grub_memset (mbi, 0, sizeof (struct grub_multiboot_info));
+
   mbi->flags = MULTIBOOT_INFO_MEMORY;

   /* Convert from bytes to kilobytes.  */

-- 
Bean


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