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 406d82d5d2bb..3edb4c2887a1 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 | |||
57 | Protocol 2.11: (Kernel 3.6) Added a field for offset of EFI handover | 57 | Protocol 2.11: (Kernel 3.6) Added a field for offset of EFI handover |
58 | protocol entry point. | 58 | protocol entry point. |
59 | 59 | ||
60 | Protocol 2.12: (Kernel 3.9) Added the xloadflags field and extension fields | ||
61 | to struct boot_params for for loading bzImage and ramdisk | ||
62 | above 4G in 64bit. | ||
63 | |||
60 | **** MEMORY LAYOUT | 64 | **** MEMORY LAYOUT |
61 | 65 | ||
62 | The traditional memory map for the kernel loader, used for Image or | 66 | The traditional memory map for the kernel loader, used for Image or |
@@ -182,7 +186,7 @@ Offset Proto Name Meaning | |||
182 | 0230/4 2.05+ kernel_alignment Physical addr alignment required for kernel | 186 | 0230/4 2.05+ kernel_alignment Physical addr alignment required for kernel |
183 | 0234/1 2.05+ relocatable_kernel Whether kernel is relocatable or not | 187 | 0234/1 2.05+ relocatable_kernel Whether kernel is relocatable or not |
184 | 0235/1 2.10+ min_alignment Minimum alignment, as a power of two | 188 | 0235/1 2.10+ min_alignment Minimum alignment, as a power of two |
185 | 0236/2 N/A pad3 Unused | 189 | 0236/2 2.12+ xloadflags Boot protocol option flags |
186 | 0238/4 2.06+ cmdline_size Maximum size of the kernel command line | 190 | 0238/4 2.06+ cmdline_size Maximum size of the kernel command line |
187 | 023C/4 2.07+ hardware_subarch Hardware subarchitecture | 191 | 023C/4 2.07+ hardware_subarch Hardware subarchitecture |
188 | 0240/8 2.07+ hardware_subarch_data Subarchitecture-specific data | 192 | 0240/8 2.07+ hardware_subarch_data Subarchitecture-specific data |
@@ -582,6 +586,27 @@ Protocol: 2.10+ | |||
582 | misaligned kernel. Therefore, a loader should typically try each | 586 | misaligned kernel. Therefore, a loader should typically try each |
583 | power-of-two alignment from kernel_alignment down to this alignment. | 587 | power-of-two alignment from kernel_alignment down to this alignment. |
584 | 588 | ||
589 | Field name: xloadflags | ||
590 | Type: read | ||
591 | Offset/size: 0x236/2 | ||
592 | Protocol: 2.12+ | ||
593 | |||
594 | This field is a bitmask. | ||
595 | |||
596 | Bit 0 (read): XLF_KERNEL_64 | ||
597 | - If 1, this kernel has the legacy 64-bit entry point at 0x200. | ||
598 | |||
599 | Bit 1 (read): XLF_CAN_BE_LOADED_ABOVE_4G | ||
600 | - If 1, kernel/boot_params/cmdline/ramdisk can be above 4G. | ||
601 | |||
602 | Bit 2 (read): XLF_EFI_HANDOVER_32 | ||
603 | - If 1, the kernel supports the 32-bit EFI handoff entry point | ||
604 | given at handover_offset. | ||
605 | |||
606 | Bit 3 (read): XLF_EFI_HANDOVER_64 | ||
607 | - If 1, the kernel supports the 64-bit EFI handoff entry point | ||
608 | given at handover_offset + 0x200. | ||
609 | |||
585 | Field name: cmdline_size | 610 | Field name: cmdline_size |
586 | Type: read | 611 | Type: read |
587 | Offset/size: 0x238/4 | 612 | Offset/size: 0x238/4 |