From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Mon, 20 Oct 2014 19:29:42 +0100 Subject: [PATCH] efi: efi-stub: notify on DTB absence Message-ID: <1413829782-12891-1-git-send-email-mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org In the absence of an DTB configuration table, the EFI stub will happily continue attempting to boot a kernel, despite the fact that this kernel may not function without a description of the hardware. In this case, as with a typo'd "dtb=" option (e.g. "dbt=") or many other possible failures, the only output seen by the user will be the rather terse output from the EFI stub: EFI stub: Booting Linux Kernel... To aid those attempting to debug such failures, this patch adds a notice when no DTB is found, making the output more helpful: EFI stub: Booting Linux Kernel... EFI stub: Generating empty DTB Similarly, a positive acknowledgement is added when a user-specified DTB is in use: EFI stub: Booting Linux Kernel... EFI stub: Using DTB from command line Signed-off-by: Mark Rutland Acked-by: Leif Lindholm Cc: Ard Biesheuvel Cc: Mark Salter Cc: Matt Fleming Cc: Roy Franz --- drivers/firmware/efi/libstub/arm-stub.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 480339b..10abf24 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -243,9 +243,16 @@ unsigned long __init efi_entry(void *handle, efi_system_table_t *sys_table, goto fail_free_cmdline; } } - if (!fdt_addr) + + if (fdt_addr) { + pr_efi(sys_table, "Using DTB from command line\n"); + } else { /* Look for a device tree configuration table entry. */ fdt_addr = (uintptr_t)get_fdt(sys_table); + } + + if (!fdt_addr) + pr_efi(sys_table, "Generating empty DTB\n"); status = handle_cmdline_files(sys_table, image, cmdline_ptr, "initrd=", dram_base + SZ_512M, -- 1.9.1