arch/powerpc/kernel/vmlinux.lds.S

   1 #ifdef CONFIG_PPC64
   2 #define PROVIDE32(x)    PROVIDE(__unused__##x)
   3 #else
   4 #define PROVIDE32(x)    PROVIDE(x)
   5 #endif
   6 #include <asm/page.h>
   7 #include <asm-generic/vmlinux.lds.h>
   8 #include <asm/cache.h>
   9 #include <asm/thread_info.h>
  10
  11 ENTRY(_stext)
  12
  13 PHDRS {
  14         kernel PT_LOAD FLAGS(7); /* RWX */
  15         notes PT_NOTE FLAGS(0);
  16         dummy PT_NOTE FLAGS(0);
  17
  18         /* binutils < 2.18 has a bug that makes it misbehave when taking an
  19            ELF file with all segments at load address 0 as input.  This
  20            happens when running "strip" on vmlinux, because of the AT() magic
  21            in this linker script.  People using GCC >= 4.2 won't run into
  22            this problem, because the "build-id" support will put some data
  23            into the "notes" segment (at a non-zero load address).
  24
  25            To work around this, we force some data into both the "dummy"
  26            segment and the kernel segment, so the dummy segment will get a
  27            non-zero load address.  It's not enough to always create the
  28            "notes" segment, since if nothing gets assigned to it, its load
  29            address will be zero.  */
  30 }
  31
  32 #ifdef CONFIG_PPC64
  33 OUTPUT_ARCH(powerpc:common64)
  34 jiffies = jiffies_64;
  35 #else
  36 OUTPUT_ARCH(powerpc:common)
  37 jiffies = jiffies_64 + 4;
  38 #endif
  39 SECTIONS
  40 {
  41         . = KERNELBASE;
  42
  43 /*
  44  * Text, read only data and other permanent read-only sections
  45  */
  46
  47         _text = .;
  48         _stext = .;
  49
  50         /*
  51          * Head text.
  52          * This needs to be in its own output section to avoid ld placing
  53          * branch trampoline stubs randomly throughout the fixed sections,
  54          * which it will do (even if the branch comes from another section)
  55          * in order to optimize stub generation.
  56          */
  57         .head.text : AT(ADDR(.head.text) - LOAD_OFFSET) {
  58 #ifdef CONFIG_PPC64
  59                 KEEP(*(.head.text.first_256B));
  60 #ifdef CONFIG_PPC_BOOK3E
  61 # define END_FIXED      0x100
  62 #else
  63                 KEEP(*(.head.text.real_vectors));
  64                 *(.head.text.real_trampolines);
  65                 KEEP(*(.head.text.virt_vectors));
  66                 *(.head.text.virt_trampolines);
  67 # if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
  68                 KEEP(*(.head.data.fwnmi_page));
  69 #  define END_FIXED     0x8000
  70 # else
  71 #  define END_FIXED     0x7000
  72 # endif
  73 #endif
  74                 ASSERT((. == END_FIXED), "vmlinux.lds.S: fixed section overflow error");
  75 #else /* !CONFIG_PPC64 */
  76                 HEAD_TEXT
  77 #endif
  78         } :kernel
  79
  80         /*
  81          * If the build dies here, it's likely code in head_64.S is referencing
  82          * labels it can't reach, and the linker inserting stubs without the
  83          * assembler's knowledge. To debug, remove the above assert and
  84          * rebuild. Look for branch stubs in the fixed section region.
  85          *
  86          * Linker stub generation could be allowed in "trampoline"
  87          * sections if absolutely necessary, but this would require
  88          * some rework of the fixed sections. Before resorting to this,
  89          * consider references that have sufficient addressing range,
  90          * (e.g., hand coded trampolines) so the linker does not have
  91          * to add stubs.
  92          *
  93          * Linker stubs at the top of the main text section are currently not
  94          * detected, and will result in a crash at boot due to offsets being
  95          * wrong.
  96          */
  97 #ifdef CONFIG_PPC64
  98         /*
  99          * BLOCK(0) overrides the default output section alignment because
 100          * this needs to start right after .head.text in order for fixed
 101          * section placement to work.
 102          */
 103         .text BLOCK(0) : AT(ADDR(.text) - LOAD_OFFSET) {
 104 #else
 105         .text : AT(ADDR(.text) - LOAD_OFFSET) {
 106                 ALIGN_FUNCTION();
 107 #endif
 108                 /* careful! __ftr_alt_* sections need to be close to .text */
 109                 *(.text .fixup __ftr_alt_* .ref.text)
 110                 SCHED_TEXT
 111                 CPUIDLE_TEXT
 112                 LOCK_TEXT
 113                 KPROBES_TEXT
 114                 IRQENTRY_TEXT
 115                 SOFTIRQENTRY_TEXT
 116                 MEM_KEEP(init.text)
 117                 MEM_KEEP(exit.text)
 118
 119 #ifdef CONFIG_PPC32
 120                 *(.got1)
 121                 __got2_start = .;
 122                 *(.got2)
 123                 __got2_end = .;
 124 #endif /* CONFIG_PPC32 */
 125
 126         } :kernel
 127
 128         . = ALIGN(PAGE_SIZE);
 129         _etext = .;
 130         PROVIDE32 (etext = .);
 131
 132         /* Read-only data */
 133         RODATA
 134
 135         EXCEPTION_TABLE(0)
 136
 137         NOTES :kernel :notes
 138
 139         /* The dummy segment contents for the bug workaround mentioned above
 140            near PHDRS.  */
 141         .dummy : AT(ADDR(.dummy) - LOAD_OFFSET) {
 142                 LONG(0)
 143                 LONG(0)
 144                 LONG(0)
 145         } :kernel :dummy
 146
 147 /*
 148  * Init sections discarded at runtime
 149  */
 150         . = ALIGN(PAGE_SIZE);
 151         __init_begin = .;
 152         INIT_TEXT_SECTION(PAGE_SIZE) :kernel
 153
 154         /* .exit.text is discarded at runtime, not link time,
 155          * to deal with references from __bug_table
 156          */
 157         .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
 158                 EXIT_TEXT
 159         }
 160
 161         .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
 162                 INIT_DATA
 163                 __vtop_table_begin = .;
 164                 *(.vtop_fixup);
 165                 __vtop_table_end = .;
 166                 __ptov_table_begin = .;
 167                 *(.ptov_fixup);
 168                 __ptov_table_end = .;
 169         }
 170
 171         .init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) {
 172                 INIT_SETUP(16)
 173         }
 174
 175         .initcall.init : AT(ADDR(.initcall.init) - LOAD_OFFSET) {
 176                 INIT_CALLS
 177         }
 178
 179         .con_initcall.init : AT(ADDR(.con_initcall.init) - LOAD_OFFSET) {
 180                 CON_INITCALL
 181         }
 182
 183         SECURITY_INIT
 184
 185         . = ALIGN(8);
 186         __ftr_fixup : AT(ADDR(__ftr_fixup) - LOAD_OFFSET) {
 187                 __start___ftr_fixup = .;
 188                 *(__ftr_fixup)
 189                 __stop___ftr_fixup = .;
 190         }
 191         . = ALIGN(8);
 192         __mmu_ftr_fixup : AT(ADDR(__mmu_ftr_fixup) - LOAD_OFFSET) {
 193                 __start___mmu_ftr_fixup = .;
 194                 *(__mmu_ftr_fixup)
 195                 __stop___mmu_ftr_fixup = .;
 196         }
 197         . = ALIGN(8);
 198         __lwsync_fixup : AT(ADDR(__lwsync_fixup) - LOAD_OFFSET) {
 199                 __start___lwsync_fixup = .;
 200                 *(__lwsync_fixup)
 201                 __stop___lwsync_fixup = .;
 202         }
 203 #ifdef CONFIG_PPC64
 204         . = ALIGN(8);
 205         __fw_ftr_fixup : AT(ADDR(__fw_ftr_fixup) - LOAD_OFFSET) {
 206                 __start___fw_ftr_fixup = .;
 207                 *(__fw_ftr_fixup)
 208                 __stop___fw_ftr_fixup = .;
 209         }
 210 #endif
 211         .init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) {
 212                 INIT_RAM_FS
 213         }
 214
 215         PERCPU_SECTION(L1_CACHE_BYTES)
 216
 217         . = ALIGN(8);
 218         .machine.desc : AT(ADDR(.machine.desc) - LOAD_OFFSET) {
 219                 __machine_desc_start = . ;
 220                 *(.machine.desc)
 221                 __machine_desc_end = . ;
 222         }
 223 #ifdef CONFIG_RELOCATABLE
 224         . = ALIGN(8);
 225         .dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET)
 226         {
 227 #ifdef CONFIG_PPC32
 228                 __dynamic_symtab = .;
 229 #endif
 230                 *(.dynsym)
 231         }
 232         .dynstr : AT(ADDR(.dynstr) - LOAD_OFFSET) { *(.dynstr) }
 233         .dynamic : AT(ADDR(.dynamic) - LOAD_OFFSET)
 234         {
 235                 __dynamic_start = .;
 236                 *(.dynamic)
 237         }
 238         .hash : AT(ADDR(.hash) - LOAD_OFFSET) { *(.hash) }
 239         .interp : AT(ADDR(.interp) - LOAD_OFFSET) { *(.interp) }
 240         .rela.dyn : AT(ADDR(.rela.dyn) - LOAD_OFFSET)
 241         {
 242                 __rela_dyn_start = .;
 243                 *(.rela*)
 244         }
 245 #endif
 246         /* .exit.data is discarded at runtime, not link time,
 247          * to deal with references from .exit.text
 248          */
 249         .exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
 250                 EXIT_DATA
 251         }
 252
 253         /* freed after init ends here */
 254         . = ALIGN(PAGE_SIZE);
 255         __init_end = .;
 256
 257 /*
 258  * And now the various read/write data
 259  */
 260
 261         . = ALIGN(PAGE_SIZE);
 262         _sdata = .;
 263
 264 #ifdef CONFIG_PPC32
 265         .data : AT(ADDR(.data) - LOAD_OFFSET) {
 266                 DATA_DATA
 267                 *(.sdata)
 268                 *(.got.plt) *(.got)
 269         }
 270 #else
 271         .data : AT(ADDR(.data) - LOAD_OFFSET) {
 272                 DATA_DATA
 273                 *(.data.rel*)
 274                 *(.toc1)
 275                 *(.branch_lt)
 276         }
 277
 278         .opd : AT(ADDR(.opd) - LOAD_OFFSET) {
 279                 *(.opd)
 280         }
 281
 282         . = ALIGN(256);
 283         .got : AT(ADDR(.got) - LOAD_OFFSET) {
 284                 __toc_start = .;
 285 #ifndef CONFIG_RELOCATABLE
 286                 __prom_init_toc_start = .;
 287                 arch/powerpc/kernel/prom_init.o*(.toc .got)
 288                 __prom_init_toc_end = .;
 289 #endif
 290                 *(.got)
 291                 *(.toc)
 292         }
 293 #endif
 294
 295         /* The initial task and kernel stack */
 296         INIT_TASK_DATA_SECTION(THREAD_SIZE)
 297
 298         .data..page_aligned : AT(ADDR(.data..page_aligned) - LOAD_OFFSET) {
 299                 PAGE_ALIGNED_DATA(PAGE_SIZE)
 300         }
 301
 302         .data..cacheline_aligned : AT(ADDR(.data..cacheline_aligned) - LOAD_OFFSET) {
 303                 CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)
 304         }
 305
 306         .data..read_mostly : AT(ADDR(.data..read_mostly) - LOAD_OFFSET) {
 307                 READ_MOSTLY_DATA(L1_CACHE_BYTES)
 308         }
 309
 310         . = ALIGN(PAGE_SIZE);
 311         .data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
 312                 NOSAVE_DATA
 313         }
 314
 315         . = ALIGN(PAGE_SIZE);
 316         _edata  =  .;
 317         PROVIDE32 (edata = .);
 318
 319 /*
 320  * And finally the bss
 321  */
 322
 323         BSS_SECTION(0, 0, 0)
 324
 325         . = ALIGN(PAGE_SIZE);
 326         _end = . ;
 327         PROVIDE32 (end = .);
 328
 329         /* Sections to be discarded. */
 330         DISCARDS
 331 }