From ad0c1a3d2cea03011091b07e9e066bf261d1556e Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@suse.de>
Date: Mon, 11 Apr 2016 23:51:01 +0200
Subject: [PATCH] efi_loader: Put fdt into convenient location
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The uEFI spec doesn't dictate where the device tree should live at, but
legacy 32bit ARM grub2 has some assumptions that it may stay at its place
when it's already loaded by the firmware.
So let's put it somewhere where Linux that comes after would happily find
it - around the recommended 128MB line.
Signed-off-by: Alexander Graf <agraf@suse.de>
Tested-by: Andreas Färber <afaerber@suse.de>
---
cmd/bootefi.c | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)
diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index 9b8af65052b..b213ef172d9 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -12,7 +12,7 @@
#include <errno.h>
#include <libfdt.h>
#include <libfdt_env.h>
-#include <malloc.h>
+#include <memalign.h>
#include <asm/global_data.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -104,12 +104,34 @@ static struct efi_object bootefi_device_obj = {
static void *copy_fdt(void *fdt)
{
u64 fdt_size = fdt_totalsize(fdt);
+ unsigned long fdt_ram_start = -1L, fdt_pages;
+ u64 new_fdt_addr;
void *new_fdt;
+ int i;
- /* Give us 64kb breathing room */
- fdt_size += 64 * 1024;
+ for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
+ u64 ram_start = gd->bd->bi_dram[i].start;
+ u64 ram_size = gd->bd->bi_dram[i].size;
- new_fdt = malloc(fdt_size);
+ if (!ram_size)
+ continue;
+
+ if (ram_start < fdt_ram_start)
+ fdt_ram_start = ram_start;
+ }
+
+ /* Give us at least 4kb breathing room */
+ fdt_size = ALIGN(fdt_size + 4096, 4096);
+ fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
+
+ /* Safe fdt location is at 128MB */
+ new_fdt_addr = fdt_ram_start + (128 * 1024 * 1024) + fdt_size;
+ if (efi_allocate_pages(1, EFI_BOOT_SERVICES_DATA, fdt_pages,
+ &new_fdt_addr) != EFI_SUCCESS) {
+ /* If we can't put it there, put it somewhere */
+ new_fdt_addr = (ulong)memalign(4096, fdt_size);
+ }
+ new_fdt = (void*)(ulong)new_fdt_addr;
memcpy(new_fdt, fdt, fdt_totalsize(fdt));
fdt_set_totalsize(new_fdt, fdt_size);
--
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