When building an XIP kernel, the linker script needs to be much different
than a conventional kernel's script. Over time, it's been difficult to
maintain both XIP and non-XIP layouts in one linker script. Therefore,
this patch separates the two procedures into two completely different
files.
The new linker script is essentially a straight copy of the current script
with all the non-CONFIG_XIP_KERNEL portions removed.
Additionally, all CONFIG_XIP_KERNEL portions have been removed from the
existing linker script...never to return again.
>From now on, for any architecture, when CONFIG_XIP_KERNEL is enabled, you
must provide a vmlinux-xip.lds.S for the build process.
Signed-off-by: Chris Brandt <chris.brandt@xxxxxxxxxxx>
---
Makefile | 4 +
arch/arm/kernel/.gitignore | 1 +
arch/arm/kernel/vmlinux-xip.lds.S | 322 +++++++++++++++++++++++++++++++++++++
arch/arm/kernel/vmlinux.lds.S | 31 +---
4 files changed, 331 insertions(+), 27 deletions(-)
create mode 100644 arch/arm/kernel/vmlinux-xip.lds.S
diff --git a/Makefile b/Makefile
index 3a0234f..b55440f 100644
--- a/Makefile
+++ b/Makefile
@@ -900,7 +900,11 @@ virt-y := $(patsubst %/, %/built-in.o, $(virt-y))
# Externally visible symbols (used by link-vmlinux.sh)
export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y) $(drivers-y) $(net-y) $(virt-y)
+ifdef CONFIG_XIP_KERNEL
+export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux-xip.lds
+else
export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
+endif
export LDFLAGS_vmlinux
# used by scripts/pacmage/Makefile
export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
diff --git a/arch/arm/kernel/.gitignore b/arch/arm/kernel/.gitignore
index c5f676c..522c636 100644
--- a/arch/arm/kernel/.gitignore
+++ b/arch/arm/kernel/.gitignore
@@ -1 +1,2 @@
vmlinux.lds
+vmlinux-xip.lds
diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
new file mode 100644
index 0000000..1fd938d
--- /dev/null
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -0,0 +1,322 @@
+/* ld script to make ARM Linux kernel
+ * taken from the i386 version by Russell King
+ * Written by Martin Mares <mj@xxxxxxxxxxxxxxxxxxxxxxxx>
+ */
+
+#include <asm-generic/vmlinux.lds.h>
+#include <asm/cache.h>
+#include <asm/thread_info.h>
+#include <asm/memory.h>
+#include <asm/page.h>
+#ifdef CONFIG_ARM_KERNMEM_PERMS
+#include <asm/pgtable.h>
+#endif
+
+#define PROC_INFO \
+ . = ALIGN(4); \
+ VMLINUX_SYMBOL(__proc_info_begin) = .; \
+ *(.proc.info.init) \
+ VMLINUX_SYMBOL(__proc_info_end) = .;
+
+#define IDMAP_TEXT \
+ ALIGN_FUNCTION(); \
+ VMLINUX_SYMBOL(__idmap_text_start) = .; \
+ *(.idmap.text) \
+ VMLINUX_SYMBOL(__idmap_text_end) = .; \
+ . = ALIGN(PAGE_SIZE); \
+ VMLINUX_SYMBOL(__hyp_idmap_text_start) = .; \
+ *(.hyp.idmap.text) \
+ VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;
+
+#ifdef CONFIG_HOTPLUG_CPU
+#define ARM_CPU_DISCARD(x)
+#define ARM_CPU_KEEP(x) x
+#else
+#define ARM_CPU_DISCARD(x) x
+#define ARM_CPU_KEEP(x)
+#endif
+
+#if (defined(CONFIG_SMP_ON_UP) && !defined(CONFIG_DEBUG_SPINLOCK)) || \
+ defined(CONFIG_GENERIC_BUG)
+#define ARM_EXIT_KEEP(x) x
+#define ARM_EXIT_DISCARD(x)
+#else
+#define ARM_EXIT_KEEP(x)
+#define ARM_EXIT_DISCARD(x) x
+#endif
+
+OUTPUT_ARCH(arm)
+ENTRY(stext)
+
+#ifndef __ARMEB__
+jiffies = jiffies_64;
+#else
+jiffies = jiffies_64 + 4;
+#endif
+
+SECTIONS
+{
+ /*
+ * XXX: The linker does not define how output sections are
+ * assigned to input sections when there are multiple statements
+ * matching the same input section name. There is no documented
+ * order of matching.
+ *
+ * unwind exit sections must be discarded before the rest of the
+ * unwind sections get included.
+ */
+ /DISCARD/ : {
+ *(.ARM.exidx.exit.text)
+ *(.ARM.extab.exit.text)
+ ARM_CPU_DISCARD(*(.ARM.exidx.cpuexit.text))
+ ARM_CPU_DISCARD(*(.ARM.extab.cpuexit.text))
+ ARM_EXIT_DISCARD(EXIT_TEXT)
+ ARM_EXIT_DISCARD(EXIT_DATA)
+ EXIT_CALL
+#ifndef CONFIG_MMU
+ *(.text.fixup)
+ *(__ex_table)
+#endif
+#ifndef CONFIG_SMP_ON_UP
+ *(.alt.smp.init)
+#endif
+ *(.discard)
+ *(.discard.*)
+ }
+
+ . = XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR);
+
+ .head.text : {
+ _text = .;
+ HEAD_TEXT
+ }
+
+#ifdef CONFIG_ARM_KERNMEM_PERMS
+ . = ALIGN(1<<SECTION_SHIFT);
+#endif
+
+ .text : { /* Real text segment */
+ _stext = .; /* Text and read-only data */
+ IDMAP_TEXT
+ __exception_text_start = .;
+ *(.exception.text)
+ __exception_text_end = .;
+ IRQENTRY_TEXT
+ TEXT_TEXT
+ SCHED_TEXT
+ LOCK_TEXT
+ KPROBES_TEXT
+ *(.gnu.warning)
+ *(.glue_7)
+ *(.glue_7t)
+ . = ALIGN(4);
+ *(.got) /* Global offset table */
+ ARM_CPU_KEEP(PROC_INFO)
+ }
+
+#ifdef CONFIG_DEBUG_RODATA
+ . = ALIGN(1<<SECTION_SHIFT);
+#endif
+ RO_DATA(PAGE_SIZE)
+
+ . = ALIGN(4);
+ __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
+ __start___ex_table = .;
+#ifdef CONFIG_MMU
+ *(__ex_table)
+#endif
+ __stop___ex_table = .;
+ }
+
+#ifdef CONFIG_ARM_UNWIND
+ /*
+ * Stack unwinding tables
+ */
+ . = ALIGN(8);
+ .ARM.unwind_idx : {
+ __start_unwind_idx = .;
+ *(.ARM.exidx*)
+ __stop_unwind_idx = .;
+ }
+ .ARM.unwind_tab : {
+ __start_unwind_tab = .;
+ *(.ARM.extab*)
+ __stop_unwind_tab = .;
+ }
+#endif
+
+ NOTES
+
+ _etext = .; /* End of text and rodata section */
+
+ /*
+ * The vectors and stubs are relocatable code, and the
+ * only thing that matters is their relative offsets
+ */
+ __vectors_start = .;
+ .vectors 0 : AT(__vectors_start) {
+ *(.vectors)
+ }
+ . = __vectors_start + SIZEOF(.vectors);
+ __vectors_end = .;
+
+ __stubs_start = .;
+ .stubs 0x1000 : AT(__stubs_start) {
+ *(.stubs)
+ }
+ . = __stubs_start + SIZEOF(.stubs);
+ __stubs_end = .;
+
+ INIT_TEXT_SECTION(8)
+ .exit.text : {
+ ARM_EXIT_KEEP(EXIT_TEXT)
+ }
+ .init.proc.info : {
+ ARM_CPU_DISCARD(PROC_INFO)
+ }
+ .init.arch.info : {
+ __arch_info_begin = .;
+ *(.arch.info.init)
+ __arch_info_end = .;
+ }
+ .init.tagtable : {
+ __tagtable_begin = .;
+ *(.taglist.init)
+ __tagtable_end = .;
+ }
+#ifdef CONFIG_SMP_ON_UP
+ .init.smpalt : {
+ __smpalt_begin = .;
+ *(.alt.smp.init)
+ __smpalt_end = .;
+ }
+#endif
+ .init.pv_table : {
+ __pv_table_begin = .;
+ *(.pv_table)
+ __pv_table_end = .;
+ }
+ .init.data : {
+ INIT_SETUP(16)
+ INIT_CALLS
+ CON_INITCALL
+ SECURITY_INITCALL
+ INIT_RAM_FS
+ }
+
+#ifdef CONFIG_SMP
+ PERCPU_SECTION(L1_CACHE_BYTES)
+#endif
+
+ __data_loc = ALIGN(4); /* location in binary */
+ . = PAGE_OFFSET + TEXT_OFFSET;
+
+ .data : AT(__data_loc) {
+ _data = .; /* address in memory */
+ _sdata = .;
+
+ /*
+ * first, the init task union, aligned
+ * to an 8192 byte boundary.
+ */
+ INIT_TASK_DATA(THREAD_SIZE)
+
+ . = ALIGN(PAGE_SIZE);
+ __init_begin = .;
+ INIT_DATA
+ ARM_EXIT_KEEP(EXIT_DATA)
+ . = ALIGN(PAGE_SIZE);
+ __init_end = .;
+
+ NOSAVE_DATA
+ CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)
+ READ_MOSTLY_DATA(L1_CACHE_BYTES)
+
+ /*
+ * and the usual data section
+ */
+ DATA_DATA
+ CONSTRUCTORS
+
+ _edata = .;
+ }
+ _edata_loc = __data_loc + SIZEOF(.data);
+
+#ifdef CONFIG_HAVE_TCM
+ /*
+ * We align everything to a page boundary so we can
+ * free it after init has commenced and TCM contents have
+ * been copied to its destination.
+ */
+ .tcm_start : {
+ . = ALIGN(PAGE_SIZE);
+ __tcm_start = .;
+ __itcm_start = .;
+ }
+
+ /*
+ * Link these to the ITCM RAM
+ * Put VMA to the TCM address and LMA to the common RAM
+ * and we'll upload the contents from RAM to TCM and free
+ * the used RAM after that.
+ */
+ .text_itcm ITCM_OFFSET : AT(__itcm_start)
+ {
+ __sitcm_text = .;
+ *(.tcm.text)
+ *(.tcm.rodata)
+ . = ALIGN(4);
+ __eitcm_text = .;
+ }
+
+ /*
+ * Reset the dot pointer, this is needed to create the
+ * relative __dtcm_start below (to be used as extern in code).
+ */
+ . = ADDR(.tcm_start) + SIZEOF(.tcm_start) + SIZEOF(.text_itcm);
+
+ .dtcm_start : {
+ __dtcm_start = .;
+ }
+
+ /* TODO: add remainder of ITCM as well, that can be used for data! */
+ .data_dtcm DTCM_OFFSET : AT(__dtcm_start)
+ {
+ . = ALIGN(4);
+ __sdtcm_data = .;
+ *(.tcm.data)
+ . = ALIGN(4);
+ __edtcm_data = .;
+ }
+
+ /* Reset the dot pointer or the linker gets confused */
+ . = ADDR(.dtcm_start) + SIZEOF(.data_dtcm);
+
+ /* End marker for freeing TCM copy in linked object */
+ .tcm_end : AT(ADDR(.dtcm_start) + SIZEOF(.data_dtcm)){
+ . = ALIGN(PAGE_SIZE);
+ __tcm_end = .;
+ }
+#endif
+
+ BSS_SECTION(0, 0, 0)
+ _end = .;
+
+ STABS_DEBUG
+}
+
+/*
+ * These must never be empty
+ * If you have to comment these two assert statements out, your
+ * binutils is too old (for other reasons as well)
+ */
+ASSERT((__proc_info_end - __proc_info_begin), "missing CPU support")
+ASSERT((__arch_info_end - __arch_info_begin), "no machine record defined")
+
+/*
+ * The HYP init code can't be more than a page long,
+ * and should not cross a page boundary.
+ * The above comment applies as well.
+ */
+ASSERT(__hyp_idmap_text_end - (__hyp_idmap_text_start & PAGE_MASK) <= PAGE_SIZE,
+ "HYP init code too big or misaligned")
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 8b60fde..2c5b76e 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -84,11 +84,7 @@ SECTIONS
*(.discard.*)
}
-#ifdef CONFIG_XIP_KERNEL
- . = XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR);
-#else
. = PAGE_OFFSET + TEXT_OFFSET;
-#endif
.head.text : {
_text = .;
HEAD_TEXT
@@ -152,14 +148,13 @@ SECTIONS
_etext = .; /* End of text and rodata section */
-#ifndef CONFIG_XIP_KERNEL
-# ifdef CONFIG_ARM_KERNMEM_PERMS
+#ifdef CONFIG_ARM_KERNMEM_PERMS
. = ALIGN(1<<SECTION_SHIFT);
-# else
+#else
. = ALIGN(PAGE_SIZE);
-# endif
- __init_begin = .;
#endif
+ __init_begin = .;
+
/*
* The vectors and stubs are relocatable code, and the
* only thing that matters is their relative offsets
@@ -208,29 +203,21 @@ SECTIONS
__pv_table_end = .;
}
.init.data : {
-#ifndef CONFIG_XIP_KERNEL
INIT_DATA
-#endif
INIT_SETUP(16)
INIT_CALLS
CON_INITCALL
SECURITY_INITCALL
INIT_RAM_FS
}
-#ifndef CONFIG_XIP_KERNEL
.exit.data : {
ARM_EXIT_KEEP(EXIT_DATA)
}
-#endif
#ifdef CONFIG_SMP
PERCPU_SECTION(L1_CACHE_BYTES)
#endif
-#ifdef CONFIG_XIP_KERNEL
- __data_loc = ALIGN(4); /* location in binary */
- . = PAGE_OFFSET + TEXT_OFFSET;
-#else
#ifdef CONFIG_ARM_KERNMEM_PERMS
. = ALIGN(1<<SECTION_SHIFT);
#else
@@ -238,7 +225,6 @@ SECTIONS
#endif
__init_end = .;
__data_loc = .;
-#endif
.data : AT(__data_loc) {
_data = .; /* address in memory */
@@ -250,15 +236,6 @@ SECTIONS
*/
INIT_TASK_DATA(THREAD_SIZE)
-#ifdef CONFIG_XIP_KERNEL
- . = ALIGN(PAGE_SIZE);
- __init_begin = .;
- INIT_DATA
- ARM_EXIT_KEEP(EXIT_DATA)
- . = ALIGN(PAGE_SIZE);
- __init_end = .;
-#endif
-
NOSAVE_DATA
CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)
READ_MOSTLY_DATA(L1_CACHE_BYTES)
--
1.7.9.5
--
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