summaryrefslogtreecommitdiffstats
path: root/Documentation/x86/boot.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/x86/boot.txt')
-rw-r--r--Documentation/x86/boot.txt18
1 files changed, 11 insertions, 7 deletions
diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index 7b4596a..e020366 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -158,7 +158,7 @@ Offset Proto Name Meaning
0202/4 2.00+ header Magic signature "HdrS"
0206/2 2.00+ version Boot protocol version supported
0208/4 2.00+ realmode_swtch Boot loader hook (see below)
-020C/2 2.00+ start_sys The load-low segment (0x1000) (obsolete)
+020C/2 2.00+ start_sys_seg The load-low segment (0x1000) (obsolete)
020E/2 2.00+ kernel_version Pointer to kernel version string
0210/1 2.00+ type_of_loader Boot loader identifier
0211/1 2.00+ loadflags Boot protocol option flags
@@ -170,10 +170,11 @@ Offset Proto Name Meaning
0224/2 2.01+ heap_end_ptr Free memory after setup end
0226/2 N/A pad1 Unused
0228/4 2.02+ cmd_line_ptr 32-bit pointer to the kernel command line
-022C/4 2.03+ initrd_addr_max Highest legal initrd address
+022C/4 2.03+ ramdisk_max Highest legal initrd address
0230/4 2.05+ kernel_alignment Physical addr alignment required for kernel
0234/1 2.05+ relocatable_kernel Whether kernel is relocatable or not
-0235/3 N/A pad2 Unused
+0235/1 N/A pad2 Unused
+0236/2 N/A pad3 Unused
0238/4 2.06+ cmdline_size Maximum size of the kernel command line
023C/4 2.07+ hardware_subarch Hardware subarchitecture
0240/8 2.07+ hardware_subarch_data Subarchitecture-specific data
@@ -299,14 +300,14 @@ Protocol: 2.00+
e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version
10.17.
-Field name: readmode_swtch
+Field name: realmode_swtch
Type: modify (optional)
Offset/size: 0x208/4
Protocol: 2.00+
Boot loader hook (see ADVANCED BOOT LOADER HOOKS below.)
-Field name: start_sys
+Field name: start_sys_seg
Type: read
Offset/size: 0x20c/2
Protocol: 2.00+
@@ -468,7 +469,7 @@ Protocol: 2.02+
zero, the kernel will assume that your boot loader does not support
the 2.02+ protocol.
-Field name: initrd_addr_max
+Field name: ramdisk_max
Type: read
Offset/size: 0x22c/4
Protocol: 2.03+
@@ -542,7 +543,10 @@ Protocol: 2.08+
The payload may be compressed. The format of both the compressed and
uncompressed data should be determined using the standard magic
- numbers. Currently only gzip compressed ELF is used.
+ numbers. The currently supported compression formats are gzip
+ (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A) and LZMA
+ (magic number 5D 00). The uncompressed payload is currently always ELF
+ (magic number 7F 45 4C 46).
Field name: payload_length
Type: read
OpenPOWER on IntegriCloud