[U-Boot] [PATCH 1/2] efi_loader: Pass fdt address directly to bootefi cmd

Alexander Graf
2016-04-13T22:41:11Z

On 14.04.16 00:26, Andreas F?rber wrote:
> Am 13.04.2016 um 23:22 schrieb Alexander Graf:
>> The bootefi cmd today fetches its device tree pointer from either the
>> location appointed by "fdt addr" with a fallback to the U-Boot control
>> fdt.
>>
>> This integration is unusual for U-Boot and diverges from the way we
>> usually handle parameters to boot commands. So let's pass the fdt
>> directly into the bootefi command instead and move the control fdt
>> logic into the distro boot script.
>>
>> Signed-off-by: Alexander Graf <agraf@suse.de>
>> ---
>> cmd/bootefi.c | 34 +++++++++++++---------------------
>> include/config_distro_bootcmd.h | 9 ++++++---
>> 2 files changed, 19 insertions(+), 24 deletions(-)
>>
>> diff --git a/cmd/bootefi.c b/cmd/bootefi.c
>> index b213ef1..ab39b95 100644
>> --- a/cmd/bootefi.c
>> +++ b/cmd/bootefi.c
>> @@ -142,12 +142,11 @@ static void *copy_fdt(void *fdt)
>> * Load an EFI payload into a newly allocated piece of memory, register all
>> * EFI objects it would want to access and jump to it.
>> */
>> -static unsigned long do_bootefi_exec(void *efi)
>> +static unsigned long do_bootefi_exec(void *efi, void *fdt)
>> {
>> ulong (*entry)(void *image_handle, struct efi_system_table *st);
>> ulong fdt_pages, fdt_size, fdt_start, fdt_end;
>> bootm_headers_t img = { 0 };
>> - void *fdt = working_fdt;
>>
>> /*
>> * gd lives in a fixed register which may get clobbered while we execute
>> @@ -155,13 +154,7 @@ static unsigned long do_bootefi_exec(void *efi)
>> */
>> efi_save_gd();
>>
>> - /* Update system table to point to our currently loaded FDT */
>> -
>> - /* Fall back to included fdt if none was manually loaded */
>> - if (!fdt && gd->fdt_blob)
>> - fdt = (void *)gd->fdt_blob;
>> -
>> - if (fdt) {
>> + if (fdt && !fdt_check_header(fdt)) {
>> /* Prepare fdt for payload */
>> fdt = copy_fdt(fdt);
>>
>> @@ -185,7 +178,7 @@ static unsigned long do_bootefi_exec(void *efi)
>> efi_add_memory_map(fdt_start, fdt_pages,
>> EFI_BOOT_SERVICES_DATA, true);
>> } else {
>> - printf("WARNING: No device tree loaded, expect boot to fail\n");
>> + printf("WARNING: Invalid device tree, expect boot to fail\n");
>> systab.nr_tables = 0;
>> }
>>
>> @@ -216,18 +209,20 @@ static unsigned long do_bootefi_exec(void *efi)
>> /* Interpreter command to boot an arbitrary EFI image from memory */
>> static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>> {
>> - char *saddr;
>> - unsigned long addr;
>> + char *saddr, *sfdt;
>> + unsigned long addr, fdt_addr;
>> int r = 0;
>>
>> - if (argc < 2)
>> + if (argc < 3)
>> return 1;
>
> Hm, I had specifically requested to make it an optional argument...
> do_bootefi_exec() seems to still handle !fdt, but here we seem to choke
> on absence of the third argument, not matching bootm/bootz/booti? GRUB
> does not need a DT to display its shell/menu, so we don't need to force
> it IMO. Think of people calling it from the prompt or from a script.
>
> Or am I misunderstanding U-Boot argument handling?

I thought that Stephen's argument was that booting Linux without a
working device tree is moot anyway. I tend to agree ;).

If you really want to boot without a device tree, you can always just
pass in "-" as the fdt argument. But by requiring a device tree we
hopefully get less confused people using the uefi support.

Alex