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x86/efi: Only load initrd above 4g on second try
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Mantas found that after commit 4bf7111 ("x86/efi: Support initrd
loaded above 4G"), the kernel freezes at the earliest possible moment
when trying to boot via UEFI on Asus laptop.

Revert to old way to load initrd under 4G on first try, second try will
use above 4G buffer when initrd is too big and does not fit under 4G.

[ The cause of the freeze appears to be a firmware bug when reading
  file data into buffers above 4GB, though the exact reason is unknown.
  Mantas reports that the hang can be avoid if the file size is a
  multiple of 512 bytes, but I've seen some ASUS firmware simply
  corrupting the file data rather than freezing.

  Laszlo fixed an issue in the upstream EDK2 DiskIO code in Aug 2013
  which may possibly be related, commit 4e39b75e ("MdeModulePkg/DiskIoDxe:
  fix source/destination pointer of overrun transfer").

  Whatever the cause, it's unlikely that a fix will be forthcoming
  from the vendor, hence the workaround - Matt ]

Cc: Laszlo Ersek <lersek@redhat.com>
Reported-by: Mantas Mikulėnas <grawity@gmail.com>
Reported-by: Harald Hoyer <harald@redhat.com>
Tested-by: Anders Darander <anders@chargestorm.se>
Tested-by: Calvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
  • Loading branch information
Yinghai Lu authored and Matt Fleming committed Sep 8, 2014
1 parent 52addcf commit 47226ad
Showing 1 changed file with 11 additions and 7 deletions.
18 changes: 11 additions & 7 deletions arch/x86/boot/compressed/eboot.c
Original file line number Diff line number Diff line change
Expand Up @@ -1032,7 +1032,6 @@ struct boot_params *make_boot_params(struct efi_config *c)
int i;
unsigned long ramdisk_addr;
unsigned long ramdisk_size;
unsigned long initrd_addr_max;

efi_early = c;
sys_table = (efi_system_table_t *)(unsigned long)efi_early->table;
Expand Down Expand Up @@ -1095,15 +1094,20 @@ struct boot_params *make_boot_params(struct efi_config *c)

memset(sdt, 0, sizeof(*sdt));

if (hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)
initrd_addr_max = -1UL;
else
initrd_addr_max = hdr->initrd_addr_max;

status = handle_cmdline_files(sys_table, image,
(char *)(unsigned long)hdr->cmd_line_ptr,
"initrd=", initrd_addr_max,
"initrd=", hdr->initrd_addr_max,
&ramdisk_addr, &ramdisk_size);

if (status != EFI_SUCCESS &&
hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G) {
efi_printk(sys_table, "Trying to load files to higher address\n");
status = handle_cmdline_files(sys_table, image,
(char *)(unsigned long)hdr->cmd_line_ptr,
"initrd=", -1UL,
&ramdisk_addr, &ramdisk_size);
}

if (status != EFI_SUCCESS)
goto fail2;
hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
Expand Down

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