grub/grub-core/kern/arm/efi/misc.c

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2013-04-07 00:41:07 +00:00
/* misc.c - various system functions for an arm-based EFI system */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2013 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/cpu/linux.h>
#include <grub/cpu/system.h>
#include <grub/efi/efi.h>
#include <grub/machine/loader.h>
static inline grub_size_t
page_align (grub_size_t size)
{
return (size + (1 << 12) - 1) & (~((1 << 12) - 1));
}
/* Find the optimal number of pages for the memory map. Is it better to
move this code to efi/mm.c? */
static grub_efi_uintn_t
find_mmap_size (void)
{
static grub_efi_uintn_t mmap_size = 0;
if (mmap_size != 0)
return mmap_size;
mmap_size = (1 << 12);
while (1)
{
int ret;
grub_efi_memory_descriptor_t *mmap;
grub_efi_uintn_t desc_size;
mmap = grub_malloc (mmap_size);
if (! mmap)
return 0;
ret = grub_efi_get_memory_map (&mmap_size, mmap, 0, &desc_size, 0);
grub_free (mmap);
if (ret < 0)
{
grub_error (GRUB_ERR_IO, "cannot get memory map");
return 0;
}
else if (ret > 0)
break;
mmap_size += (1 << 12);
}
/* Increase the size a bit for safety, because GRUB allocates more on
later, and EFI itself may allocate more. */
mmap_size += (1 << 12);
return page_align (mmap_size);
}
#define NEXT_MEMORY_DESCRIPTOR(desc, size) \
((grub_efi_memory_descriptor_t *) ((char *) (desc) + (size)))
#define PAGE_SHIFT 12
void *
grub_efi_allocate_loader_memory (grub_uint32_t min_offset, grub_uint32_t size)
{
grub_efi_uintn_t desc_size;
grub_efi_memory_descriptor_t *mmap, *mmap_end;
grub_efi_uintn_t mmap_size, tmp_mmap_size;
grub_efi_memory_descriptor_t *desc;
void *mem = NULL;
grub_addr_t min_start = 0;
mmap_size = find_mmap_size();
if (!mmap_size)
return NULL;
mmap = grub_malloc(mmap_size);
if (!mmap)
return NULL;
tmp_mmap_size = mmap_size;
if (grub_efi_get_memory_map (&tmp_mmap_size, mmap, 0, &desc_size, 0) <= 0)
{
grub_error (GRUB_ERR_IO, "cannot get memory map");
goto fail;
}
mmap_end = NEXT_MEMORY_DESCRIPTOR (mmap, tmp_mmap_size);
/* Find lowest accessible RAM location */
{
int found = 0;
for (desc = mmap ; !found && (desc < mmap_end) ;
desc = NEXT_MEMORY_DESCRIPTOR(desc, desc_size))
{
switch (desc->type)
{
case GRUB_EFI_CONVENTIONAL_MEMORY:
case GRUB_EFI_LOADER_CODE:
case GRUB_EFI_LOADER_DATA:
min_start = desc->physical_start + min_offset;
found = 1;
break;
default:
break;
}
}
}
/* First, find free pages for the real mode code
and the memory map buffer. */
for (desc = mmap ; desc < mmap_end ;
desc = NEXT_MEMORY_DESCRIPTOR(desc, desc_size))
{
grub_uint64_t start, end;
grub_dprintf("mm", "%s: 0x%08x bytes @ 0x%08x\n",
__FUNCTION__,
(grub_uint32_t) (desc->num_pages << PAGE_SHIFT),
(grub_uint32_t) (desc->physical_start));
if (desc->type != GRUB_EFI_CONVENTIONAL_MEMORY)
continue;
start = desc->physical_start;
end = start + (desc->num_pages << PAGE_SHIFT);
grub_dprintf("mm", "%s: start=0x%016llx, end=0x%016llx\n",
__FUNCTION__, start, end);
start = start < min_start ? min_start : start;
if (start + size > end)
continue;
grub_dprintf("mm", "%s: let's allocate some (0x%x) pages @ 0x%08x...\n",
__FUNCTION__, (size >> PAGE_SHIFT), (grub_addr_t) start);
mem = grub_efi_allocate_pages (start, (size >> PAGE_SHIFT) + 1);
grub_dprintf("mm", "%s: retval=0x%08x\n",
__FUNCTION__, (grub_addr_t) mem);
if (! mem)
{
grub_error (GRUB_ERR_OUT_OF_MEMORY, "cannot allocate memory");
goto fail;
}
break;
}
if (! mem)
{
grub_error (GRUB_ERR_OUT_OF_MEMORY, "cannot allocate memory");
goto fail;
}
grub_free (mmap);
return mem;
fail:
grub_free (mmap);
return NULL;
}
grub_err_t
grub_efi_prepare_platform (void)
{
grub_efi_uintn_t mmap_size;
grub_efi_uintn_t map_key;
grub_efi_uintn_t desc_size;
grub_efi_uint32_t desc_version;
grub_efi_memory_descriptor_t *mmap_buf;
grub_err_t err;
/*
* Cloned from IA64
* Must be done after grub_machine_fini because map_key is used by
*exit_boot_services.
*/
mmap_size = find_mmap_size ();
if (! mmap_size)
return GRUB_ERR_OUT_OF_MEMORY;
mmap_buf = grub_efi_allocate_pages (0, page_align (mmap_size) >> 12);
if (! mmap_buf)
return GRUB_ERR_OUT_OF_MEMORY;
err = grub_efi_finish_boot_services (&mmap_size, mmap_buf, &map_key,
&desc_size, &desc_version);
if (err != GRUB_ERR_NONE)
return err;
grub_arm_disable_caches_mmu();
return GRUB_ERR_NONE;
}