ARM: better diagnostics with missing/corrupt dtb (99cf8f90) · Commits · 戴 / test

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 <j-keerthy@ti.com> Signed-off-by:

Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/kernel/atags_parse.c

+2 −5

Original line number	Diff line number	Diff line
		@@ -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);

arch/arm/kernel/setup.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -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);

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