sw/device/lib/testing/test_framework/ottf_smc.ld

/* Copyright lowRISC contributors. */
/* Licensed under the Apache License, Version 2.0, see LICENSE for details. */
/* SPDX-License-Identifier: Apache-2.0 */

/**
 * Linker script for OpenTitan OTTF-launched test binaries.
 *
 * Portions of this file are Ibex-specific.
 *
 * This linker script generates a binary to run rom.
 */

SEARCH_DIR ( external/matcha )
INCLUDE hw/top_matcha/sw/autogen/top_matcha_memory.ld
MEMORY {
  virtual(rx): ORIGIN = 0x10000, LENGTH = 0x400000
  super_virtual(rx): ORIGIN = 0xff800000, LENGTH = 0x400000
}

/**
 * Reserving space at the top of the RAM for DV verification.
 */
_dv_sim_window_size = 0x10;
_dv_sim_window_end = ORIGIN(ram_smc) + LENGTH(ram_smc);
_dv_sim_window_start = _dv_sim_window_end - _dv_sim_window_size;

/**
 * Reserving space at the top of the RAM for the stack.
 */
_stack_size = 0x2000;
_stack_end = _dv_sim_window_start;
_stack_start = _stack_end - _stack_size;

/**
 * DV Log offset.
 * TODO: this will need to be different depending on the boot stage the OTTF is
 * launched at. See lowrisc/opentitan:#10712.
 */
_dv_log_offset = 0x10000;

OUTPUT_ARCH(riscv)

/**
 * Indicate that there are no dynamic libraries, whatsoever.
 */
__DYNAMIC = 0;

/**
 * Marking the entry point correctly for the ELF file. The signer tool will
 * transfer this value to the `entry_point` field of the manifest, which will
 * then be used by `rom_boot` or `rom_ext_boot` to handover execution to
 * the OTTF.
 */
ENTRY(_ottf_start);

/**
 * NOTE: We have to align each section to word boundaries as our current
 * s19->slm conversion scripts are not able to handle non-word aligned sections.
 */
SECTIONS {
  /**
   * Ibex interrupt vector. See 'ottf_start.S' for more information.
   *
   * This has to be set up at a 256-byte offset, so that we can use it with
   * Ibex.
   */
  .vectors : ALIGN (256){
    _text_start = .;
    *(.vectors)
  } > ram_smc

  /**
   * C runtime (CRT) section, containing program initialization code.
   */
  .crt : ALIGN(4) {
    KEEP(*(.crt))
  } > ram_smc

  /**
   * For LLVM profiling. This contains a pointer to the runtime initialization
   * function that is generated by the compiler. See
   * 'InstrProfiling::emitInitialization()' in 'InstrProfiling.cpp' and
   * 'getInstrProfInitFuncName()' in 'InstrProf.h'.
   */
  .init_array : ALIGN(4) {
      _init_array_start = .;
      KEEP(*(.init_array))
      KEEP(*(.init_array.*))
      . = ALIGN(4);
      _init_array_end = .;
  } > ram_smc

  /**
   * Standard text section, containing program code.
   */
  .text : ALIGN(4) {
    *(.text)
    *(.text.*)

    /* Ensure section end is word-aligned. */
    . = ALIGN(4);
  } > ram_smc

  /**
   * Shutdown text section, containing shutdown function(s).
   *
   * This must be the last executable section in the OTTF flash image.
   */
  .shutdown : ALIGN(4) {
    *(.shutdown)
    *(.shutdown.*)

    /* Ensure section end is word-aligned. */
    . = ALIGN(4);
    _text_end = .;
  } > ram_smc

  /**
   * Read-only data section, containing all large compile-time constants, like
   * strings.
   */
  .rodata : ALIGN(4) {
    /**
     * Small read-only data comes before regular read-only data for the same
     * reasons as in the data section.
     */
    *(.srodata)
    *(.srodata.*)
    *(.rodata)
    *(.rodata.*)

    /* Read-only sections for LLVM profiling. */
    KEEP(*(__llvm_covfun))
    KEEP(*(__llvm_covmap))
    KEEP(*(__llvm_prf_names))
  } > ram_smc

  /**
   * Standard mutable data section, at the bottom of RAM. This will be
   * initialized from the .idata section at runtime by the CRT.
   */
  .data : ALIGN(4) {
    _data_start = .;
    _data_init_start = LOADADDR(.data);

    /**
     * This will get loaded into `gp`, and the linker will use that register for
     * accessing data within [-2048,2047] of `__global_pointer$`.
     *
     * This is much cheaper (for small data) than materializing the
     * address and loading from that (which will take one extra instruction).
     */
    __global_pointer$ = . + 2048;

    /* SRAM programs embedded in functional tests must come first. */
    *(.data.sram_program)

    /**
     * Small data should come before larger data. This helps to ensure small
     * globals are within 2048 bytes of the value of `gp`, making their accesses
     * hopefully only take one instruction.
     */
    *(.sdata)
    *(.sdata.*)

    /**
     * Other data will likely need multiple instructions to load, so we're less
     * concerned about address materialisation taking more than one instruction.
     */
    *(.data)
    *(.data.*)

    /* Sections for LLVM profiling. */
    KEEP(*(__llvm_prf_cnts))
    KEEP(*(__llvm_prf_data))

    /* Ensure section end is word-aligned. */
    . = ALIGN(4);
    _data_end = .;
    _data_init_end = LOADADDR(.data) + SIZEOF(.data);

    /**
     * This puts it in ram_smc at runtime (for the VMA), but puts the section
     * into flash for load time (for the LMA). This is why `_data_init_*` uses
     * `LOADADDR`.
     *
     * Using `AT>` means we don't have to keep track of the next free part of
     * flash, as we do in our other linker scripts.
     */
  } > ram_smc

  /**
   * Standard BSS section. This will be zeroed at runtime by the CRT.
   */
  .bss : ALIGN(4) {
    _bss_start = .;

    /**
     * Small BSS comes before regular BSS for the same reasons as in the data
     * section.
     */
    *(.sbss)
    *(.sbss.*)
    *(.bss)
    *(.bss.*)

    /* Ensure section end is word-aligned. */
    . = ALIGN(4);
    _bss_end = .;
  } > ram_smc

  /**
   * FreeRTOS heap (for OTTF).
   *
   * This is a separate NOLOAD section so that it does not end up in the `.bss`
   * section which gets zeroed during the second boot stage initialization,
   * causing wasted simulation cycles.
   */
  .freertos.heap (NOLOAD): ALIGN(4) {
    _freertos_heap_start = .;
    *(.freertos.heap)
  } > ram_smc

  . = ALIGN(4096);
  __VIRTUAL_ROM = .;
  .virtual : AT(__VIRTUAL_ROM)
  {
   __virtual_start = .;
   *(.virtual*)
   . = ALIGN(4096);
   __virtual_end = .;
  } > virtual

  __SUPER_VIRTUAL_ROM = __VIRTUAL_ROM + (__virtual_end - __virtual_start);
  .super_virtual : AT(__SUPER_VIRTUAL_ROM)
  {
   __super_virtual_start = .;
   *(.super_virtual*)
   __super_virtual_end = .;
  } > super_virtual

  .stack ORIGIN(ram_smc) + LENGTH(ram_smc) - _stack_size - _dv_sim_window_size (NOLOAD) : ALIGN(4) {
    __stack_start__ = .;
    . += _stack_size;
    . = ALIGN(4);
    __stack_end__ = .;
  } > ram_smc


  INCLUDE external/lowrisc_opentitan/sw/device/info_sections.ld
}