xref: /openbmc/u-boot/arch/xtensa/cpu/u-boot.lds (revision baefb63a) 
1/*
2 * (C) Copyright 2008 - 2013 Tensilica, Inc.
3 * (C) Copyright 2014 - 2016 Cadence Design Systems Inc.
4 *
5 * SPDX-License-Identifier:	GPL-2.0+
6 */
7
8#include <config.h>
9#include <asm/ldscript.h>
10#include <asm/arch/core.h>
11#include <asm/addrspace.h>
12#include <asm-offsets.h>
13
14OUTPUT_ARCH(xtensa)
15ENTRY(_start)
16
17/*
18 * U-Boot resets from SYSROM and unpacks itself from a ROM store to RAM.
19 * The reset vector is usually near the base of SYSROM and has room
20 * above it for the ROM store into which the rest of U-Boot is packed.
21 * The ROM store also needs to be above any other vectors that are in ROM.
22 * If a core has its vectors near the top of ROM, this must be edited.
23 *
24 * Note that to run C code out of ROM, the processor would have to support
25 * 'relocatable' exception vectors and provide a scratch memory for the
26 * initial stack. Not all Xtensa processor configurations support that, so
27 * we can simplify the boot process and unpack U-Boot to RAM immediately.
28 * This, however, requires that memory have been initialized throug some
29 * other means (serial ROM, for example) or are initialized early (requiring
30 * an assembler function. See start.S for more details)
31 */
32
33SECTIONS
34{
35  . = + SIZEOF_HEADERS;
36  SECTION_ResetVector(XCHAL_RESET_VECTOR_VADDR, LMA_EQ_VMA)
37
38  .reloc_table ALIGN(4) : FOLLOWING(.ResetVector.text)
39  {
40    __reloc_table_start = ABSOLUTE(.);
41#if XCHAL_HAVE_WINDOWED
42    RELOCATE2(WindowVectors,text);
43#endif
44    RELOCATE2(KernelExceptionVector,literal);
45    RELOCATE2(KernelExceptionVector,text);
46    RELOCATE2(UserExceptionVector,literal);
47    RELOCATE2(UserExceptionVector,text);
48    RELOCATE2(DoubleExceptionVector,literal);
49    RELOCATE2(DoubleExceptionVector,text);
50    RELOCATE1(text);
51    RELOCATE1(rodata);
52    RELOCATE1(data);
53    RELOCATE1(u_boot_list);
54    __reloc_table_end = ABSOLUTE(.);
55  }
56
57#if XCHAL_HAVE_WINDOWED
58  SECTION_VECTOR(WindowVectors,text,XCHAL_WINDOW_VECTORS_VADDR,
59		 FOLLOWING(.reloc_table))
60  SECTION_VECTOR(KernelExceptionVector,literal,XCHAL_KERNEL_VECTOR_VADDR-8,
61		 FOLLOWING(.WindowVectors.text))
62#else
63  SECTION_VECTOR(KernelExceptionVector,literal,XCHAL_KERNEL_VECTOR_VADDR-8,
64		 FOLLOWING(.reloc_table))
65#endif
66  SECTION_VECTOR(KernelExceptionVector,text,XCHAL_KERNEL_VECTOR_VADDR,
67		 FOLLOWING(.KernelExceptionVector.literal))
68  SECTION_VECTOR(UserExceptionVector,literal,XCHAL_USER_VECTOR_VADDR-8,
69		 FOLLOWING(.KernelExceptionVector.text))
70  SECTION_VECTOR(UserExceptionVector,text,XCHAL_USER_VECTOR_VADDR,
71		 FOLLOWING(.UserExceptionVector.literal))
72  SECTION_VECTOR(DoubleExceptionVector,literal,XCHAL_DOUBLEEXC_VECTOR_VADDR-8,
73		 FOLLOWING(.UserExceptionVector.text))
74  SECTION_VECTOR(DoubleExceptionVector,text,XCHAL_DOUBLEEXC_VECTOR_VADDR,
75		 FOLLOWING(.DoubleExceptionVector.literal))
76
77  __monitor_start = CONFIG_SYS_TEXT_ADDR;
78
79  SECTION_text(CONFIG_SYS_TEXT_ADDR, FOLLOWING(.DoubleExceptionVector.text))
80  SECTION_rodata(ALIGN(16), FOLLOWING(.text))
81  SECTION_u_boot_list(ALIGN(16), FOLLOWING(.rodata))
82  SECTION_data(ALIGN(16), FOLLOWING(.u_boot_list))
83
84  __reloc_end = .;
85  __init_end = .;
86
87  SECTION_bss(__init_end (OVERLAY),)
88
89  __monitor_end = .;
90
91  /*
92   * On many Xtensa boards a region of RAM may be mapped to the ROM address
93   * space to facilitate on-chip-debug, and U-Boot must fit with that region.
94   * The config variables CONFIG_SYS_MONITOR_* define the region.
95   * If U-Boot extends beyond this region it will appear discontiguous in the
96   * address space and is in danger of overwriting itself during unpacking
97   * ("relocation").
98   * This causes U-Boot to crash in a way that is difficult to debug. On some
99   * boards (such as xtav60) the region is small enough that U-Boot will not
100   * fit if compiled entirely with -O0 (a common scenario). To avoid a lengthy
101   * debugging session when this happens, ensure a link-time error occurs.
102   *
103   */
104
105   ASSERT(__monitor_end - __monitor_start <= CONFIG_SYS_MONITOR_LEN,
106          "U-Boot ROM image is too large. Check optimization level.")
107
108  SECTION_xtensa
109  SECTION_debug
110
111  /DISCARD/ : { *(.dynstr*) }
112  /DISCARD/ : { *(.hash*) }
113  /DISCARD/ : { *(.interp) }
114  /DISCARD/ : { *(.got*) }
115  /DISCARD/ : { *(.dynsym) }
116}
117