| caa3e7e0 | 22-Apr-2020 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
linker_script: move .data section to bl_common.ld.h
Move the data section to the common header.
I slightly tweaked some scripts as follows:
[1] bl1.ld.S has ALIGN(16). I added DATA_ALIGN macro, wh
linker_script: move .data section to bl_common.ld.h
Move the data section to the common header.
I slightly tweaked some scripts as follows:
[1] bl1.ld.S has ALIGN(16). I added DATA_ALIGN macro, which is 1 by default, but overridden by bl1.ld.S. Currently, ALIGN(16) of the .data section is redundant because commit 412865907699 ("Fix boot failures on some builds linked with ld.lld.") padded out the previous section to work around the issue of LLD version <= 10.0. This will be fixed in the future release of LLVM, so I am keeping the proper way to align LMA.
[2] bl1.ld.S and bl2_el3.ld.S define __DATA_RAM_{START,END}__ instead of __DATA_{START,END}__. I put them out of the .data section.
[3] SORT_BY_ALIGNMENT() is missing tsp.ld.S, sp_min.ld.S, and mediatek/mt6795/bl31.ld.S. This commit adds SORT_BY_ALIGNMENT() for all images, so the symbol order in those three will change, but I do not think it is a big deal.
Change-Id: I215bb23c319f045cd88e6f4e8ee2518c67f03692 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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| b9f7b57d | 07-Apr-2020 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
bl1: remove '.' from stacks section in linker script
Only BL1 specifies '.' in the address field of the stacks section.
Commit 4f59d8359f97 ("Make BL1 RO and RW base addresses configurable") added
bl1: remove '.' from stacks section in linker script
Only BL1 specifies '.' in the address field of the stacks section.
Commit 4f59d8359f97 ("Make BL1 RO and RW base addresses configurable") added '.' on purpose but the commit message does not help to understand why.
This commit gets rid of it in order to factor out the stacks section into include/common/bl_common.ld.h
I compared the build result for PLAT=qemu.
'aarch64-linux-gnu-nm -n build/qemu/release/bl1/bl1.elf' will change as follows:
@@ -336,8 +336,8 @@ 000000000e04e0e0 d max_log_level 000000000e04e0e4 D console_state 000000000e04e0e5 D __DATA_RAM_END__ -000000000e04e0e5 B __STACKS_START__ 000000000e04e100 b platform_normal_stacks +000000000e04e100 B __STACKS_START__ 000000000e04f100 b bl1_cpu_context 000000000e04f100 B __BSS_START__ 000000000e04f100 B __STACKS_END__
After this change, __STACKS_START__ will match to platform_normal_stacks, and I think it makes more sense.
'aarch64-linux-gnu-objdump -h build/qemu/release/bl1/bl1.elf' will change as follows:
@@ -9,11 +9,11 @@ CONTENTS, ALLOC, LOAD, READONLY, DATA 2 .data 000000e5 000000000e04e000 0000000000004a60 0001e000 2**4 CONTENTS, ALLOC, LOAD, DATA - 3 stacks 0000101b 000000000e04e0e5 000000000e04e0e5 0001e0e5 2**6 + 3 stacks 00001000 000000000e04e100 0000000000004b45 0001e100 2**6 ALLOC - 4 .bss 000007e0 000000000e04f100 000000000e04f100 0001e0e5 2**5 + 4 .bss 000007e0 000000000e04f100 0000000000004b50 0001f100 2**5 ALLOC - 5 xlat_table 00006000 000000000e050000 000000000e050000 0001e0e5 2**12 + 5 xlat_table 00006000 000000000e050000 0000000000004b45 00020000 2**12 ALLOC 6 coherent_ram 00000000 000000000e056000 000000000e056000 0001f000 2**12 CONTENTS
Sandrine pointed me to a useful document [1] to understand why LMAs of stacks, .bss, and xlat_table section have changed.
Before this patch, they fell into this scenario: "If the section has a specific VMA address, then this is used as the LMA address as well."
With this commit, the following applies: "Otherwise if a memory region can be found that is compatible with the current section, and this region contains at least one section, then the LMA is set so the difference between the VMA and LMA is the same as the difference between the VMA and LMA of the last section in the located region."
Anyway, those three sections are not loaded, so the LMA changes will not be a problem. The size of bl1.bin is still the same.
QEMU still boots successfully with this change.
A good thing is, this fixes the error for the latest LLD. If I use the mainline LLVM, I see the following error. The alignment check will probably be included in the LLVM 11 release, so it is better to fix it now.
$ PLAT=qemu CC=clang CROSS_COMPILE=aarch64-linux-gnu- [ snip ] ld.lld: error: address (0xe04e0e5) of section stacks is not a multiple of alignment (64) make: *** [Makefile:1050: build/qemu/release/bl1/bl1.elf] Error 1
[1]: https://sourceware.org/binutils/docs/ld/Output-Section-LMA.html#Output-Section-LMA
Change-Id: I3d2f3cc2858be8b3ce2eab3812a76d1e0b5f3a32 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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| a7739bc7 | 26-Mar-2020 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
linker_script: move bss section to bl_common.ld.h
Move the bss section to the common header. This adds BAKERY_LOCK_NORMAL and PMF_TIMESTAMP, which previously existed only in BL31. This is not a big
linker_script: move bss section to bl_common.ld.h
Move the bss section to the common header. This adds BAKERY_LOCK_NORMAL and PMF_TIMESTAMP, which previously existed only in BL31. This is not a big deal because unused data should not be compiled in the first place. I believe this should be controlled by BL*_SOURCES in Makefiles, not by linker scripts.
I investigated BL1, BL2, BL2U, BL31 for plat=fvp, and BL2-AT-EL3, BL31, BL31 for plat=uniphier. I did not see any more unexpected code addition.
The bss section has bigger alignment. I added BSS_ALIGN for this.
Currently, SORT_BY_ALIGNMENT() is missing in sp_min.ld.S, and with this change, the BSS symbols in SP_MIN will be sorted by the alignment. This is not a big deal (or, even better in terms of the image size).
Change-Id: I680ee61f84067a559bac0757f9d03e73119beb33 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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| 0a0a7a9a | 26-Mar-2020 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
linker_script: replace common read-only data with RODATA_COMMON
The common section data are repeated in many linker scripts (often twice in each script to support SEPARATE_CODE_AND_RODATA). When you
linker_script: replace common read-only data with RODATA_COMMON
The common section data are repeated in many linker scripts (often twice in each script to support SEPARATE_CODE_AND_RODATA). When you add a new read-only data section, you end up with touching lots of places.
After this commit, you will only need to touch bl_common.ld.h when you add a new section to RODATA_COMMON.
Replace a series of RO section with RODATA_COMMON, which contains 6 sections, some of which did not exist before.
This is not a big deal because unneeded data should not be compiled in the first place. I believe this should be controlled by BL*_SOURCES in Makefiles, not by linker scripts.
When I was working on this commit, the BL1 image size increased due to the fconf_populator. Commit c452ba159c14 ("fconf: exclude fconf_dyn_cfg_getter.c from BL1_SOURCES") fixed this issue.
I investigated BL1, BL2, BL2U, BL31 for plat=fvp, and BL2-AT-EL3, BL31, BL31 for plat=uniphier. I did not see any more unexpected code addition.
Change-Id: I5d14d60dbe3c821765bce3ae538968ef266f1460 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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