diff options
| -rw-r--r-- | arch/x86/include/asm/bootparam_utils.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/x86/include/asm/bootparam_utils.h b/arch/x86/include/asm/bootparam_utils.h index ff808ef4fdb4..653668d140f9 100644 --- a/arch/x86/include/asm/bootparam_utils.h +++ b/arch/x86/include/asm/bootparam_utils.h @@ -19,8 +19,22 @@ */ static void sanitize_boot_params(struct boot_params *boot_params) { + /* + * IMPORTANT NOTE TO BOOTLOADER AUTHORS: do not simply clear + * this field. The purpose of this field is to guarantee + * compliance with the x86 boot spec located in + * Documentation/x86/boot.txt . That spec says that the + * *whole* structure should be cleared, after which only the + * portion defined by struct setup_header (boot_params->hdr) + * should be copied in. + * + * If you're having an issue because the sentinel is set, you + * need to change the whole structure to be cleared, not this + * (or any other) individual field, or you will soon have + * problems again. + */ if (boot_params->sentinel) { - /*fields in boot_params are not valid, clear them */ + /* fields in boot_params are left uninitialized, clear them */ memset(&boot_params->olpc_ofw_header, 0, (char *)&boot_params->efi_info - (char *)&boot_params->olpc_ofw_header); |