From fb884381273669fad034538e6cb186678407cf22 Mon Sep 17 00:00:00 2001 From: "Huang, Ying" Date: Fri, 28 Mar 2008 10:49:50 +0800 Subject: x86, boot: Document for linked list of struct setup_data Documentation for linked list of struct setup_data. Signed-off-by: Huang Ying Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- Documentation/i386/boot.txt | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/Documentation/i386/boot.txt b/Documentation/i386/boot.txt index 2eb1610..0fac346 100644 --- a/Documentation/i386/boot.txt +++ b/Documentation/i386/boot.txt @@ -42,6 +42,8 @@ Protocol 2.05: (Kernel 2.6.20) Make protected mode kernel relocatable. Protocol 2.06: (Kernel 2.6.22) Added a field that contains the size of the boot command line +Protocol 2.09: (kernel 2.6.26) Added a field of 64-bit physical + pointer to single linked list of struct setup_data. **** MEMORY LAYOUT @@ -172,6 +174,8 @@ Offset Proto Name Meaning 0240/8 2.07+ hardware_subarch_data Subarchitecture-specific data 0248/4 2.08+ payload_offset Offset of kernel payload 024C/4 2.08+ payload_length Length of kernel payload +0250/8 2.09+ setup_data 64-bit physical pointer to linked list + of struct setup_data (1) For backwards compatibility, if the setup_sects field contains 0, the real value is 4. @@ -572,6 +576,28 @@ command line is entered using the following protocol: covered by setup_move_size, so you may need to adjust this field. +Field name: setup_data +Type: write (obligatory) +Offset/size: 0x250/8 +Protocol: 2.09+ + + The 64-bit physical pointer to NULL terminated single linked list of + struct setup_data. This is used to define a more extensible boot + parameters passing mechanism. The definition of struct setup_data is + as follow: + + struct setup_data { + u64 next; + u32 type; + u32 len; + u8 data[0]; + }; + + Where, the next is a 64-bit physical pointer to the next node of + linked list, the next field of the last node is 0; the type is used + to identify the contents of data; the len is the length of data + field; the data holds the real payload. + **** MEMORY LAYOUT OF THE REAL-MODE CODE -- cgit v1.1