From 99cf8f903148347e3d2ac86ffe98bb04bebc6983 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 21 Sep 2017 12:06:20 +0100 Subject: [PATCH] ARM: better diagnostics with missing/corrupt dtb With a kernel containing both DT and atag support, the diagnostics output when the dtb is missing or corrupt assume that we're trying to boot using atags and the machine ID, and only print the machine ID. This is not useful for diagnosing a missing or corrupt dtb. Move the message into arch/arm/kernel/setup.c, and print the address of the dtb/atag list, and the first 16 bytes of memory of the dtb or atag list. This allows us to see whether the dtb was corrupted in some way, causing the fallback to the machine ID / atag list. Tested-by: Keerthy Signed-off-by: Russell King --- arch/arm/kernel/atags_parse.c | 7 ++----- arch/arm/kernel/setup.c | 10 ++++++++++ 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/arch/arm/kernel/atags_parse.c b/arch/arm/kernel/atags_parse.c index 98fbfd235ac8..c10a3e8ee998 100644 --- a/arch/arm/kernel/atags_parse.c +++ b/arch/arm/kernel/atags_parse.c @@ -196,11 +196,8 @@ setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr) break; } - if (!mdesc) { - early_print("\nError: unrecognized/unsupported machine ID" - " (r1 = 0x%08x).\n\n", machine_nr); - dump_machine_table(); /* does not return */ - } + if (!mdesc) + return NULL; if (__atags_pointer) tags = phys_to_virt(__atags_pointer); diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 8e9a3e40d949..fc40a2b40595 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -1069,6 +1069,16 @@ void __init setup_arch(char **cmdline_p) mdesc = setup_machine_fdt(__atags_pointer); if (!mdesc) mdesc = setup_machine_tags(__atags_pointer, __machine_arch_type); + if (!mdesc) { + early_print("\nError: invalid dtb and unrecognized/unsupported machine ID\n"); + early_print(" r1=0x%08x, r2=0x%08x\n", __machine_arch_type, + __atags_pointer); + if (__atags_pointer) + early_print(" r2[]=%*ph\n", 16, + phys_to_virt(__atags_pointer)); + dump_machine_table(); + } + machine_desc = mdesc; machine_name = mdesc->name; dump_stack_set_arch_desc("%s", mdesc->name); -- 2.30.2