- 12 May, 2009 7 commits
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H. Peter Anvin authored
A long ago, in days of yore, it all began with a god named Thor. There were vikings and boats and some plans for a Linux kernel header. Unfortunately, a single 8-bit field was used for bootloader type and version. This has generally worked without *too* much pain, but we're getting close to flat running out of ID fields. Add extension fields for both type and version. The type will be extended if it the old field is 0xE; the version is a simple MSB extension. Keep /proc/sys/kernel/bootloader_type containing (type << 4) + (ver & 0xf) for backwards compatiblity, but also add /proc/sys/kernel/bootloader_version which contains the full version number. [ Impact: new feature to support more bootloaders ] Signed-off-by:H. Peter Anvin <hpa@zytor.com>
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H. Peter Anvin authored
Update CONFIG_RELOCATABLE, CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN to reflect the current defaults. [ Impact: make defconfig match Kconfig defaults ] Signed-off-by: -
H. Peter Anvin authored
Update defconfigs to reflect current configuration files. No other changes. [ Impact: updates defconfigs to match what "make defconfig" generates ] Signed-off-by: -
H. Peter Anvin authored
Remove the EXPERIMENTAL tag from CONFIG_RELOCATABLE and make it the default. Relocatable kernels have been used for a while now, and should now have identical semantics to non-relocatable kernels when loaded by a non-relocating bootloader. Signed-off-by: -
H. Peter Anvin authored
Default CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN each to 16 MB, so that both non-relocatable and relocatable kernels are loaded at 16 MB by a non-relocating bootloader. This is somewhat hacky, but it appears to be the only way to do this that does not break some some set of existing bootloaders. We want to avoid the bottom 16 MB because of large page breakup, memory holes, and ZONE_DMA. Embedded systems may need to reduce this, or update their bootloaders to be aware of the new min_alignment field. [ Impact: performance improvement, avoids problems on some systems ] Signed-off-by: -
H. Peter Anvin authored
Document the new bzImage fields for kernel memory placement. [ Impact: adds documentation ] Signed-off-by: -
H. Peter Anvin authored
Make the kernel_alignment field adjustable; this allows us to set it to a large value (intended to be 16 MB to avoid ZONE_DMA contention, memory holes and other weirdness) while a smart bootloader can still force a loading at a lesser alignment if absolutely necessary. Also export pref_address (preferred loading address, corresponding to the link-time address) and init_size, the total amount of linear memory the kernel will require during initialization. [ Impact: allows better kernel placement, gives bootloader more info ] Signed-off-by:
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- 11 May, 2009 3 commits
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H. Peter Anvin authored
Remove a couple of lines of dead code from arch/x86/boot/compressed/head_*.S; all of these update registers that are dead in the current code. [ Impact: cleanup ] Signed-off-by: -
H. Peter Anvin authored
Use LOAD_PHYSICAL_ADDR instead of CONFIG_PHYSICAL_START in the 64-bit decompression code, for equivalence with the 32-bit code. [ Impact: cleanup, increases code similarity ] Signed-off-by: -
H. Peter Anvin authored
Make symbols from the main vmlinux, as opposed to just compressed/vmlinux, available to header.S. Also, export a few additional symbols. This will be used in a subsequent patch to export the total memory footprint of the kernel. [ Impact: enable future enhancement ] Signed-off-by:
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- 09 May, 2009 13 commits
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H. Peter Anvin authored
Determine the compressed code offset (from the kernel runtime address) at compile time. This allows some minor optimizations in arch/x86/boot/compressed/head_*.S, but more importantly it makes this value available to the build process, which will enable a future patch to export the necessary linear memory footprint into the bzImage header. [ Impact: cleanup, future patch enabling ] Signed-off-by: -
H. Peter Anvin authored
In the pre-decompression code, use the appropriate largest possible rep movs and rep stos to move code and clear bss, respectively. For reverse copy, do note that the initial values are supposed to be the address of the first (highest) copy datum, not one byte beyond the end of the buffer. rep strings are not necessarily the fastest way to perform these operations on all current processors, but are likely to be in the future, and perhaps more importantly, we want to encourage the architecturally right thing to do here. This also fixes a couple of trivial inefficiencies on 64 bits. [ Impact: trivial performance enhancement, increase code similarity ] Signed-off-by: -
H. Peter Anvin authored
The 64-bit code already clears EFLAGS as soon as it has a stack. This seems like a reasonable precaution, so do it on 32 bits as well. [ Impact: extra paranoia ] Signed-off-by: -
H. Peter Anvin authored
Set up the decompression stack as soon as we know where it needs to go. That way we have a full-service stack as soon as possible, rather than relying on the BP_scratch field. Note that the stack does need to be empty during bss zeroing (or else the stack needs to be moved out of the bss segment, which is also an option.) [ Impact: cleanup, minor paranoia ] Signed-off-by: -
H. Peter Anvin authored
Both on 32 and 64 bits, we copy all the way up to the end of bss, except that on 64 bits there is a hack to avoid copying on top of the page tables. There is no point in copying bss at all, especially since we are just about to zero it all anyway. To clean up and unify the handling, we now do: - copy from startup_32 to _bss. - zero from _bss to _ebss. - the _ebss symbol is aligned to an 8-byte boundary. - the page tables are moved to a separate section. Use _bss as the copy endpoint since _edata may be misaligned. [ Impact: cleanup, trivial performance improvement ] Signed-off-by: -
H. Peter Anvin authored
Clean up style issues in arch/x86/boot/compressed/head_64.S. This file had a lot fewer style issues than its 32-bit cousin, but the ones it has are worth fixing, especially since it makes the two files more similar. [ Impact: cleanup, no object code change ] Signed-off-by: -
H. Peter Anvin authored
Reformat arch/x86/boot/compressed/head_32.S to be closer to currently preferred kernel assembly style, that is: - opcode and operand separated by tab - operands separated by ", " - C-style comments This also makes it more similar to head_64.S. [ Impact: cleanup, no object code change ] Signed-off-by: -
H. Peter Anvin authored
Use the BP_scratch symbol from asm-offsets.h instead of hard-coding the location. [ Impact: cleanup ] Signed-off-by: -
H. Peter Anvin authored
When generating the compression suffix in arch/x86/boot/compressed/Makefile, follow standard Kbuild conventions, that is: - Use a dash not underscore before y/m/n endings - Use := whenever possible. Requested-by:
Sam Ravnborg <sam@ravnborg.org> Signed-off-by:
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H. Peter Anvin authored
Simplify the arch/x86/boot/compressed/Makefile, by using the new capability of specifying multiple inputs to a compressor, and the CONFIG_X86_NEED_RELOCS Kconfig symbol. Signed-off-by:
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H. Peter Anvin authored
We only need to build relocations when we are building a 32-bit relocatable kernel. Rather than unnecessarily complicating the Makefiles, make an explicit Kbuild symbol for this. [ Impact: permits future cleanup ] Signed-off-by: -
H. Peter Anvin authored
Allow the compression commands in Kbuild (i.e. gzip, bzip2, lzma) to take multiple input files and emit the concatenated compressed output. This avoids an intermediate step when a kernel image is built from multiple components, such as the relocatable x86-32 kernel. Sam Ravnborg integrated the bin_size script into the Makefile. [ Impact: new build feature, not yet used ] Signed-off-by:
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H. Peter Anvin authored
Aligning the .bss section makes it trivial to use large operation sizes for moving the initialized sections and clearing the .bss. The alignment chosen (L1 cache) is somewhat arbitrary, but should be large enough to avoid all known performance traps and small enough to not cause troubles. [ Impact: trivial performance enhancement, future patch prep ] Signed-off-by:
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- 30 Apr, 2009 1 commit
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Sam Ravnborg authored
Jesper reported that he saw following build issue: > ld:arch/x86/boot/compressed/vmlinux.lds:9: syntax error > make[2]: *** [arch/x86/boot/compressed/vmlinux] Error 1 > make[1]: *** [arch/x86/boot/compressed/vmlinux] Error 2 > make: *** [bzImage] Error 2 CPP defines the symbol "i386" to "1". Undefine this to fix it. [ Impact: build fix with certain tool chains ] Reported-by:
Jesper Dangaard Brouer <jdb@comx.dk> Signed-off-by:
Ingo Molnar <mingo@elte.hu>
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- 29 Apr, 2009 15 commits
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Ingo Molnar authored
__init_begin/_end symbols should be inside sections as well, otherwise the relocatable kernel gets confused when freeing init sections in the wrong place. [ Impact: fix bootup crash ] Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Tim Abbott <tabbott@MIT.EDU> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20090429105056.GA28720@uranus.ravnborg.org> Signed-off-by: -
Ingo Molnar authored
Acked-by:
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Sam Ravnborg authored
32 bit: - explicit page align .bss - move ALING() out of .brk output section - discard *(.eh_frame) 64 bit: - move ALIGN() out of .bss output section - move ALIGN() out of .brk output section - use a dedicated section to define _end [ Impact: unify and fix section alignments in linker script ] Signed-off-by:
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Sam Ravnborg authored
32 bit: - move __init_end outside the .bss output section It really did not belong in there [ Impact: 64-bit: cleanup, 32-bit: refactor linker script ] Signed-off-by:
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Sam Ravnborg authored
[ Impact: cleanup ] Signed-off-by:
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Sam Ravnborg authored
32 bit: - increase alignment from 4 to 8 for .parainstructions - increase alignment from 4 to 8 for .altinstructions 64 bit: - move ALIGN() outside output section for .altinstructions None of the above should result in any functional change. [ Impact: refactor and unify linker script ] Signed-off-by:
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Sam Ravnborg authored
32-bit: - Move definition of __init_begin outside output_section because it covers more than one section - Move ALIGN() for end-of-section inside .smp_locks output section. Same effect but the intent is better documented that we need both start and end aligned. 64-bit: - Move ALIGN() outside output section in .init.setup - Deleted unused __smp_alt_* symbols None of the above should result in any functional change. [ Impact: refactor and unify linker script ] Signed-off-by:
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Sam Ravnborg authored
[ Impact: cleanup ] Signed-off-by:
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Sam Ravnborg authored
For 64 bit the following functional changes are introduced: - .data.page_aligned has moved - .data.cacheline_aligned has moved - .data.read_mostly has moved - ALIGN() moved out of output section for .data.cacheline_aligned - ALIGN() moved out of output section for .data.page_aligned Notice that 32 bit and 64 bit has different location of _edata. .data_nosave is 32 bit only as 64 bit is special due to PERCPU. [ Impact: 32-bit: cleanup, 64-bit: use 32-bit linker script ] Signed-off-by:
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Sam Ravnborg authored
[ Impact: cleanup ] Signed-off-by:
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Sam Ravnborg authored
32 bit x86 had a dedicated .text.head output section, whereas 64 bit had it all in a single output section. In the unified version the dedicated .text.head output section was kept to have full control over the head code. 32 bit: - Moved definition of _stext to the linker script. The definition is located _after_ .text.page_aligned as this is what 32 bit did before. The ALIGN(8) was introduced so we hit the exact same address (on the tested config) before and after the move. I assume that it is a bug that _stext did not cover the .text.page_aligned section - if this is true it can be fixed in a follow-up patch (and the ugly ALIGN() can be dropped). [ Impact: 64-bit: cleanup, 32-bit: use the 64-bit linker script ] Signed-off-by:
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Sam Ravnborg authored
[ Impact: cleanup ] Signed-off-by:
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Sam Ravnborg authored
PHDRS are not equal for the two - so use ifdefs to cover up for that. On the assumption that they may become equal the ifdef is inside the PHDRS definiton. [ Impact: cleanup ] Signed-off-by:
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Sam Ravnborg authored
Merge everything except PHDRS and SECTIONS into vmlinux.lds.S. [ Impact: cleanup ] Signed-off-by:
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Sam Ravnborg authored
Beautify vmlinux_32.lds.S: - Use tabs for indent - Located curly braces like in C code - Rearranged a few comments To see actual differences use "git diff -b" which ignore 'whitespace' changes. The beautification is done to prepare a unification of the _32 and _64 variants of the linker scripts. [ Impact: cleanup ] Signed-off-by:
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- 27 Apr, 2009 1 commit
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Linus Torvalds authored
Look at the: diff -u arch/x86/boot/compressed/vmlinux_*.lds output and realize that they're basially exactly the same except for trivial naming differences, and the fact that the 64-bit version has a "pgtable" thing. So unify them. There's some trivial cleanup there (make the output format a Kconfig thing rather than doing #ifdef's for it, and unify both 32-bit and 64-bit BSS end to "_ebss", where 32-bit used to use the traditional "_end"), but other than that it's really very mindless and straigt conversion. For example, I think we should aim to remove "startup_32" vs "startup_64", and just call it "startup", and get rid of one more difference. I didn't do that. Also, notice the comment in the unified vmlinux.lds.S talks about "head_64" and "startup_32" which is an odd and incorrect mix, but that was actually what the old 64-bit only lds file had, so the confusion isn't new, and now that mixing is arguably more accurate thanks to the vmlinux.lds.S file being shared between the two cases ;) [ Impact: cleanup, unification ] Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Acked-by:
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