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freebsd-skq/sys/conf/ldscript.i386

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Add $FreeBSD$ Make the alpha linker script more like the i386 version - delete the /usr/local and egcs directories
2000-01-11 15:35:16 +00:00
/* $FreeBSD$ */
Use the new freebsd output format from Binutils 2.13.1.
2002-10-11 19:38:04 +00:00
OUTPUT_FORMAT("elf32-i386-freebsd", "elf32-i386-freebsd", "elf32-i386-freebsd")
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
OUTPUT_ARCH(i386)
ENTRY(btext)
Remove a rather bogus search path reference..
1999-06-03 22:07:41 +00:00
SEARCH_DIR(/usr/lib);
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
SECTIONS
{
/* Read-only sections, merged into text segment: */
i386 4/4G split. The change makes the user and kernel address spaces on i386 independent, giving each almost the full 4G of usable virtual addresses except for one PDE at top used for trampoline and per-CPU trampoline stacks, and system structures that must be always mapped, namely IDT, GDT, common TSS and LDT, and process-private TSS and LDT if allocated. By using 1:1 mapping for the kernel text and data, it appeared possible to eliminate assembler part of the locore.S which bootstraps initial page table and KPTmap. The code is rewritten in C and moved into the pmap_cold(). The comment in vmparam.h explains the KVA layout. There is no PCID mechanism available in protected mode, so each kernel/user switch forth and back completely flushes the TLB, except for the trampoline PTD region. The TLB invalidations for userspace becomes trivial, because IPI handlers switch page tables. On the other hand, context switches no longer need to reload %cr3. copyout(9) was rewritten to use vm_fault_quick_hold(). An issue for new copyout(9) is compatibility with wiring user buffers around sysctl handlers. This explains two kind of locks for copyout ptes and accounting of the vslock() calls. The vm_fault_quick_hold() AKA slow path, is only tried after the 'fast path' failed, which temporary changes mapping to the userspace and copies the data to/from small per-cpu buffer in the trampoline. If a page fault occurs during the copy, it is short-circuit by exception.s to not even reach C code. The change was motivated by the need to implement the Meltdown mitigation, but instead of KPTI the full split is done. The i386 architecture already shows the sizing problems, in particular, it is impossible to link clang and lld with debugging. I expect that the issues due to the virtual address space limits would only exaggerate and the split gives more liveness to the platform. Tested by: pho Discussed with: bde Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D14633
2018-04-13 20:30:49 +00:00
. = kernbase + SIZEOF_HEADERS;
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.interp : { *(.interp) }
.hash : { *(.hash) }
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
.gnu.hash : { *(.gnu.hash) }
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.dynsym : { *(.dynsym) }
.dynstr : { *(.dynstr) }
.gnu.version : { *(.gnu.version) }
.gnu.version_d : { *(.gnu.version_d) }
.gnu.version_r : { *(.gnu.version_r) }
.rel.init : { *(.rel.init) }
.rela.init : { *(.rela.init) }
.rel.text : { *(.rel.text .rel.text.* .rel.gnu.linkonce.t.*) }
.rela.text : { *(.rela.text .rela.text.* .rela.gnu.linkonce.t.*) }
.rel.fini : { *(.rel.fini) }
.rela.fini : { *(.rela.fini) }
.rel.rodata : { *(.rel.rodata .rel.rodata.* .rel.gnu.linkonce.r.*) }
.rela.rodata : { *(.rela.rodata .rela.rodata.* .rela.gnu.linkonce.r.*) }
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
.rel.data.rel.ro : { *(.rel.data.rel.ro* .rel.gnu.linkonce.d.rel.ro.*) }
.rela.data.rel.ro : { *(.rela.data.rel.ro* .rela.gnu.linkonce.d.rel.ro.*) }
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.rel.data : { *(.rel.data .rel.data.* .rel.gnu.linkonce.d.*) }
.rela.data : { *(.rela.data .rela.data.* .rela.gnu.linkonce.d.*) }
.rel.tdata : { *(.rel.tdata .rel.tdata.* .rel.gnu.linkonce.td.*) }
.rela.tdata : { *(.rela.tdata .rela.tdata.* .rela.gnu.linkonce.td.*) }
.rel.tbss : { *(.rel.tbss .rel.tbss.* .rel.gnu.linkonce.tb.*) }
.rela.tbss : { *(.rela.tbss .rela.tbss.* .rela.gnu.linkonce.tb.*) }
.rel.ctors : { *(.rel.ctors) }
.rela.ctors : { *(.rela.ctors) }
.rel.dtors : { *(.rel.dtors) }
.rela.dtors : { *(.rela.dtors) }
.rel.got : { *(.rel.got) }
.rela.got : { *(.rela.got) }
.rel.bss : { *(.rel.bss .rel.bss.* .rel.gnu.linkonce.b.*) }
.rela.bss : { *(.rela.bss .rela.bss.* .rela.gnu.linkonce.b.*) }
.rel.plt : { *(.rel.plt) }
.rela.plt : { *(.rela.plt) }
.init :
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
{
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
KEEP (*(.init))
use INT3 instead of NOP for x86 binary padding We should never end up executing the inter-function padding, so we are better off faulting than silently carrying on to whatever function happens to be next. Note that LLD will soon do this by default (although it currently pads with zeros). Reviewed by: dim, kib MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D10047
2017-03-19 00:22:13 +00:00
} =0xCCCCCCCC
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.plt : { *(.plt) }
.text :
{
*(.text .stub .text.* .gnu.linkonce.t.*)
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
KEEP (*(.text.*personality*))
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
/* .gnu.warning sections are handled specially by elf32.em. */
*(.gnu.warning)
use INT3 instead of NOP for x86 binary padding We should never end up executing the inter-function padding, so we are better off faulting than silently carrying on to whatever function happens to be next. Note that LLD will soon do this by default (although it currently pads with zeros). Reviewed by: dim, kib MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D10047
2017-03-19 00:22:13 +00:00
} =0xCCCCCCCC
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.fini :
{
KEEP (*(.fini))
use INT3 instead of NOP for x86 binary padding We should never end up executing the inter-function padding, so we are better off faulting than silently carrying on to whatever function happens to be next. Note that LLD will soon do this by default (although it currently pads with zeros). Reviewed by: dim, kib MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D10047
2017-03-19 00:22:13 +00:00
} =0xCCCCCCCC
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
PROVIDE (__etext = .);
PROVIDE (_etext = .);
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
PROVIDE (etext = .);
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) }
.rodata1 : { *(.rodata1) }
Expose the kernel's build-ID through sysctl After our migration (of certain architectures) to lld the kernel is built with a unique build-ID. Make it available via a sysctl and uname(1) to allow the user to identify their running kernel. Submitted by: Ali Mashtizadeh <ali_mashtizadeh.com> MFC after: 2 weeks Relnotes: Yes Event: Waterloo Hackathon 2019 Differential Revision: https://reviews.freebsd.org/D20326
2019-06-04 13:07:10 +00:00
.note.gnu.build-id : {
PROVIDE (__build_id_start = .);
*(.note.gnu.build-id)
PROVIDE (__build_id_end = .);
}
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.eh_frame_hdr : { *(.eh_frame_hdr) }
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
.eh_frame : ONLY_IF_RO { KEEP (*(.eh_frame)) }
.gcc_except_table : ONLY_IF_RO { *(.gcc_except_table .gcc_except_table.*) }
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
/* Adjust the address for the data segment. We want to adjust up to
the same address within the page on the next page up. */
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
. = ALIGN (CONSTANT (MAXPAGESIZE)) - ((CONSTANT (MAXPAGESIZE) - .) & (CONSTANT (MAXPAGESIZE) - 1)); . = DATA_SEGMENT_ALIGN (CONSTANT (MAXPAGESIZE), CONSTANT (COMMONPAGESIZE));
/* Exception handling */
.eh_frame : ONLY_IF_RW { KEEP (*(.eh_frame)) }
.gcc_except_table : ONLY_IF_RW { *(.gcc_except_table .gcc_except_table.*) }
/* Thread Local Storage sections */
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.tdata : { *(.tdata .tdata.* .gnu.linkonce.td.*) }
.tbss : { *(.tbss .tbss.* .gnu.linkonce.tb.*) *(.tcommon) }
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
.preinit_array :
{
PROVIDE_HIDDEN (__preinit_array_start = .);
KEEP (*(.preinit_array))
PROVIDE_HIDDEN (__preinit_array_end = .);
}
.init_array :
{
PROVIDE_HIDDEN (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array))
PROVIDE_HIDDEN (__init_array_end = .);
}
.fini_array :
{
PROVIDE_HIDDEN (__fini_array_start = .);
KEEP (*(.fini_array))
KEEP (*(SORT(.fini_array.*)))
PROVIDE_HIDDEN (__fini_array_end = .);
}
Add two symbols start_ctors and stop_ctors to allow us to find the .ctors section so we can call the constructors.
2003-01-06 07:37:15 +00:00
_start_ctors = .;
PROVIDE (start_ctors = .);
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.ctors :
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
{
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
/* gcc uses crtbegin.o to find the start of
the constructors, so we make sure it is
first. Because this is a wildcard, it
doesn't matter if the user does not
actually link against crtbegin.o; the
linker won't look for a file to match a
wildcard. The wildcard also means that it
doesn't matter which directory crtbegin.o
is in. */
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
KEEP (*crtbegin.o(.ctors))
KEEP (*crtbegin?.o(.ctors))
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
/* We don't want to include the .ctor section from
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
the crtend.o file until after the sorted ctors.
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
The .ctor section from the crtend file contains the
end of ctors marker and it must be last */
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o ) .ctors))
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
KEEP (*(SORT(.ctors.*)))
KEEP (*(.ctors))
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
}
Add two symbols start_ctors and stop_ctors to allow us to find the .ctors section so we can call the constructors.
2003-01-06 07:37:15 +00:00
_stop_ctors = .;
PROVIDE (stop_ctors = .);
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.dtors :
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
{
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
KEEP (*crtbegin.o(.dtors))
KEEP (*crtbegin?.o(.dtors))
KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o ) .dtors))
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
KEEP (*(SORT(.dtors.*)))
KEEP (*(.dtors))
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
}
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.jcr : { KEEP (*(.jcr)) }
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
.data.rel.ro : { *(.data.rel.ro.local* .gnu.linkonce.d.rel.ro.local.*) *(.data.rel.ro* .gnu.linkonce.d.rel.ro.*) }
.dynamic : { *(.dynamic) }
.got : { *(.got) }
. = DATA_SEGMENT_RELRO_END (12, .);
.got.plt : { *(.got.plt) }
.data :
{
*(.data .data.* .gnu.linkonce.d.*)
KEEP (*(.gnu.linkonce.d.*personality*))
}
.data1 : { *(.data1) }
_edata = .; PROVIDE (edata = .);
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.bss :
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
{
Fix placement of __bss_start in i386 kernel linker script With lld 7.0.0, a rather nasty problem in our kernel linker script came to light. We use quite a lot of so-called "orphan" sections, e.g. sections which are not explicitly named in the linker script. Mainly, these are the linker sets (such as set_sysinit_set). Note that the placement of these orphan sections is not very well defined. Usually, any read-only orphan sections get placed after the last read-only section from the linker script, and similarly for the read/write variants. In our linker scripts, there are also symbol assignments like _etext, _edata, and __bss_start, which are used in various places to refer to the start or end addresses of sections. However, some of these symbol assignments are interspersed with output section descriptions. While the linker will guarantee that a symbol assignment after some section will stay after that section, there is no guarantee that an orphan section cannot be inserted just before it. Take for example the following script: SECTIONS { .data : { *(.data) } __bss_start = .; .bss : { *(.bss) } } If an orphan section (like set_sysinit_set) is now inserted just after the __bss_start assignment, __bss_start will actually point to the start of that orphan section, *not* to the start of the .bss section. Unfortunately, something like this happened with our i386 kernel linker script, and since sys/i386/i386/locore.s tries to zero .bss, it ended up zeroing all the linker sets too, leading to a crash very soon after the <--BOOT--> message. To fix this, move the __bss_start symbol assignment *into* the .bss section description, so there is no way a linker can then insert orphan sections at that point. Also add a corresponding __bss_end symbol. In addition, change sys/i386/i386/locore.s, so it clears from __bss_start to __bss_end, instead of assuming that _edata is just before .bss (which may not be true), and that _end is just after _bss (which also may not be true). This allows an i386 kernel linked with lld 7.0.0 to boot successfully.
2018-10-11 20:44:25 +00:00
__bss_start = .;
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
*(.dynbss)
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
*(.bss .bss.* .gnu.linkonce.b.*)
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
*(COMMON)
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
/* Align here to ensure that the .bss section occupies space up to
_end. Align after .bss to ensure correct alignment even if the
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
.bss section disappears because there are no input sections.
FIXME: Why do we need it? When there is no .bss section, we don't
pad the .data section. */
. = ALIGN(. != 0 ? 32 / 8 : 1);
Fix placement of __bss_start in i386 kernel linker script With lld 7.0.0, a rather nasty problem in our kernel linker script came to light. We use quite a lot of so-called "orphan" sections, e.g. sections which are not explicitly named in the linker script. Mainly, these are the linker sets (such as set_sysinit_set). Note that the placement of these orphan sections is not very well defined. Usually, any read-only orphan sections get placed after the last read-only section from the linker script, and similarly for the read/write variants. In our linker scripts, there are also symbol assignments like _etext, _edata, and __bss_start, which are used in various places to refer to the start or end addresses of sections. However, some of these symbol assignments are interspersed with output section descriptions. While the linker will guarantee that a symbol assignment after some section will stay after that section, there is no guarantee that an orphan section cannot be inserted just before it. Take for example the following script: SECTIONS { .data : { *(.data) } __bss_start = .; .bss : { *(.bss) } } If an orphan section (like set_sysinit_set) is now inserted just after the __bss_start assignment, __bss_start will actually point to the start of that orphan section, *not* to the start of the .bss section. Unfortunately, something like this happened with our i386 kernel linker script, and since sys/i386/i386/locore.s tries to zero .bss, it ended up zeroing all the linker sets too, leading to a crash very soon after the <--BOOT--> message. To fix this, move the __bss_start symbol assignment *into* the .bss section description, so there is no way a linker can then insert orphan sections at that point. Also add a corresponding __bss_end symbol. In addition, change sys/i386/i386/locore.s, so it clears from __bss_start to __bss_end, instead of assuming that _edata is just before .bss (which may not be true), and that _end is just after _bss (which also may not be true). This allows an i386 kernel linked with lld 7.0.0 to boot successfully.
2018-10-11 20:44:25 +00:00
__bss_end = .;
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
}
. = ALIGN(32 / 8);
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
. = ALIGN(32 / 8);
_end = .; PROVIDE (end = .);
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
. = DATA_SEGMENT_END (.);
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
/* Stabs debugging sections. */
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.stab 0 : { *(.stab) }
.stabstr 0 : { *(.stabstr) }
.stab.excl 0 : { *(.stab.excl) }
.stab.exclstr 0 : { *(.stab.exclstr) }
.stab.index 0 : { *(.stab.index) }
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
.stab.indexstr 0 : { *(.stab.indexstr) }
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.comment 0 : { *(.comment) }
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
/* DWARF debug sections.
Symbols in the DWARF debugging sections are relative to the beginning
of the section so we begin them at 0. */
/* DWARF 1 */
.debug 0 : { *(.debug) }
.line 0 : { *(.line) }
/* GNU DWARF 1 extensions */
.debug_srcinfo 0 : { *(.debug_srcinfo) }
.debug_sfnames 0 : { *(.debug_sfnames) }
/* DWARF 1.1 and DWARF 2 */
.debug_aranges 0 : { *(.debug_aranges) }
.debug_pubnames 0 : { *(.debug_pubnames) }
/* DWARF 2 */
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
.debug_info 0 : { *(.debug_info .gnu.linkonce.wi.*) }
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
.debug_abbrev 0 : { *(.debug_abbrev) }
.debug_line 0 : { *(.debug_line) }
.debug_frame 0 : { *(.debug_frame) }
.debug_str 0 : { *(.debug_str) }
.debug_loc 0 : { *(.debug_loc) }
.debug_macinfo 0 : { *(.debug_macinfo) }
/* SGI/MIPS DWARF 2 extensions */
.debug_weaknames 0 : { *(.debug_weaknames) }
.debug_funcnames 0 : { *(.debug_funcnames) }
.debug_typenames 0 : { *(.debug_typenames) }
.debug_varnames 0 : { *(.debug_varnames) }
Step 2: sync sys/conf/ldscript.i386 with the binutils 2.17.50 version, again preserving FreeBSD-specific customizations.
2010-11-05 19:40:27 +00:00
/* DWARF 3 */
.debug_pubtypes 0 : { *(.debug_pubtypes) }
.debug_ranges 0 : { *(.debug_ranges) }
.gnu.attributes 0 : { KEEP (*(.gnu.attributes)) }
Step 1: sync sys/conf/ldscript.i386 with the binutils 2.15 version, preserving FreeBSD-specific customizations (in particular, the addition of _start_ctors and _stop_ctors).
2010-11-05 19:30:30 +00:00
/DISCARD/ : { *(.note.GNU-stack) }
Make the ELF kernel build produce a dynamic executable (!). This enables the in-kernel linker to access the _DYNAMIC data for doing loadable elf modules. The alpha kernel is already done this way, I've borrowed some of the hacks from there. This is primarily aimed at the 3-stage boot process which is intended to be able to do pre-loading of kernel modules. Note that the entry point isn't 0xf0100000 any more, it'll be a little further on - but this value is stored in the headers. I don't think this will be a problem, but I'm sure somebody will tell me if it is. :-) I'm not sure if btxboot is going to like this, it doesn't do proper ELF header checking and assumes that there are exactly two program header entries and that they are both PT_LOAD entries - a bad assumption.
1998-09-30 12:14:39 +00:00
}
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