cmd: bootefi: allocate device-tree copy from high memory

The bootefi command creates a copy of the device-tree within the first
127 MiB of memory. This may lead to overwriting previously loaded binaries
(e.g. kernel, initrd).

Linux EFI stub itself copies U-Boot's copy of the device-tree. This means
there is not restriction for U-Boot to place the device-tree copy to any
address. (Restrictions existed for 32bit ARM before Linux commit
7a1be318f579 ("ARM: 9012/1: move device tree mapping out of linear region")
for legacy booting.

Reported-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>

diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index 6618335ddf9f1567d8c7306b0af13cbd87936f68..8aa15a64c83617eb25de641e2ebddd82803e9338 100644 (file)
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -204,25 +204,12 @@ static efi_status_t copy_fdt(void **fdtp)
        fdt_pages = efi_size_in_pages(fdt_totalsize(fdt) + 0x3000);
        fdt_size = fdt_pages << EFI_PAGE_SHIFT;
 
-       /*
-        * Safe fdt location is at 127 MiB.
-        * On the sandbox convert from the sandbox address space.
-        */
-       new_fdt_addr = (uintptr_t)map_sysmem(fdt_ram_start + 0x7f00000 +
-                                            fdt_size, 0);
-       ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
+       ret = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES,
                                 EFI_ACPI_RECLAIM_MEMORY, fdt_pages,
                                 &new_fdt_addr);
        if (ret != EFI_SUCCESS) {
-               /* If we can't put it there, put it somewhere */
-               new_fdt_addr = (ulong)memalign(EFI_PAGE_SIZE, fdt_size);
-               ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
-                                        EFI_ACPI_RECLAIM_MEMORY, fdt_pages,
-                                        &new_fdt_addr);
-               if (ret != EFI_SUCCESS) {
-                       log_err("ERROR: Failed to reserve space for FDT\n");
-                       goto done;
-               }
+               log_err("ERROR: Failed to reserve space for FDT\n");
+               goto done;
        }
        new_fdt = (void *)(uintptr_t)new_fdt_addr;
        memcpy(new_fdt, fdt, fdt_totalsize(fdt));