On 2/23/23 16:57, Heinrich Schuchardt wrote:
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));
Ard gave me this information:
When booting via UEFI the device-tree is copied by the EFI stub to an
appropriate location. There are no restriction for U-Boot's choice.
For legacy booting ARMv7 before
ARM: 9012/1: move device tree mapping out of linear region
7a1be318f5795cb66fa0dc86b3ace427fe68057f
the device-tree had to be placed in a linear region of customizable
size. The general recommendation was to place the device-tree in the
second 128 MiB block.
I will convert the diff above into a patch.
Best regards
Heinrich
