bootefi issue

[Heinrich Schuchardt]

On 2/23/23 14:38, Alexandre Ghiti wrote:
> Hi Heinrich,
> 
> I fell into an issue in u-boot, and I struggle to find the correct
> fix: I'm loading a kernel of 66MB at kernel_addr_r (=0x8400_0000, this
> is the default value) and then I'm booting it using bootefi. But the
> loaded kernel is overwritten by the fdt because u-boot loads the dtb
> at 0x87f0_0000 (https://elixir.bootlin.com/u-boot/v2023.01/source/cmd/bootefi.c#L211:
> I guess efi_allocate_pages does not fail because the efi allocator is
> not aware of the kernel that was loaded there). So I have multiple
> fixes and don't know which one is right:
> 
> 1. bootefi could load the kernel first and then the fdt (so that the
> efi allocator fails at 0x87f0_0000)
> 2. check before efi_allocate_pages that the "normal" allocator is free
> there (I tried malloc_usable_size but it fails).
> 3. decrease kernel_addr_r...But I would disagree :)
> 
> Any idea?
> 
> Thanks,
> 
> Alex

Hello Alexandre,

this address for copying the device-tree dates back to 2016-04-11 when 
AllocatePages() didn't work properly.

For riscv64 I see no reason why we should not use a high address.

@Ilias
Does ARM have any problem with the device-tree being in high memory? 
Otherwise we should make a change as in the diff below.

Best regards

Heinrich


diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index 6618335ddf..08a0cfa764 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -210,19 +210,12 @@ static efi_status_t copy_fdt(void **fdtp)
          */
         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));