diff options
Diffstat (limited to 'Documentation/x86/boot.txt')
| -rw-r--r-- | Documentation/x86/boot.txt | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt index 406d82d5d2b..3edb4c2887a 100644 --- a/Documentation/x86/boot.txt +++ b/Documentation/x86/boot.txt @@ -57,6 +57,10 @@ Protocol 2.10: (Kernel 2.6.31) Added a protocol for relaxed alignment Protocol 2.11: (Kernel 3.6) Added a field for offset of EFI handover protocol entry point. +Protocol 2.12: (Kernel 3.9) Added the xloadflags field and extension fields + to struct boot_params for for loading bzImage and ramdisk + above 4G in 64bit. + **** MEMORY LAYOUT The traditional memory map for the kernel loader, used for Image or @@ -182,7 +186,7 @@ Offset Proto Name Meaning 0230/4 2.05+ kernel_alignment Physical addr alignment required for kernel 0234/1 2.05+ relocatable_kernel Whether kernel is relocatable or not 0235/1 2.10+ min_alignment Minimum alignment, as a power of two -0236/2 N/A pad3 Unused +0236/2 2.12+ xloadflags Boot protocol option flags 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 @@ -582,6 +586,27 @@ Protocol: 2.10+ misaligned kernel. Therefore, a loader should typically try each power-of-two alignment from kernel_alignment down to this alignment. +Field name: xloadflags +Type: read +Offset/size: 0x236/2 +Protocol: 2.12+ + + This field is a bitmask. + + Bit 0 (read): XLF_KERNEL_64 + - If 1, this kernel has the legacy 64-bit entry point at 0x200. + + Bit 1 (read): XLF_CAN_BE_LOADED_ABOVE_4G + - If 1, kernel/boot_params/cmdline/ramdisk can be above 4G. + + Bit 2 (read): XLF_EFI_HANDOVER_32 + - If 1, the kernel supports the 32-bit EFI handoff entry point + given at handover_offset. + + Bit 3 (read): XLF_EFI_HANDOVER_64 + - If 1, the kernel supports the 64-bit EFI handoff entry point + given at handover_offset + 0x200. + Field name: cmdline_size Type: read Offset/size: 0x238/4 |