Line data    Source code

       1           0 : /*
       2             :  * Copyright (c) 2023 Nordic Semiconductor ASA
       3             :  *
       4             :  * SPDX-License-Identifier: Apache-2.0
       5             :  */
       6             : 
       7             : /*
       8             :  * DESCRIPTION
       9             :  * Platform independent set of macros for creating a memory segment for
      10             :  * aggregating data that shall be kept in the elf file but not in the binary.
      11             :  */
      12             : 
      13             : #ifndef ZEPHYR_INCLUDE_LINKER_LINKER_DEVNULL_H_
      14             : #define ZEPHYR_INCLUDE_LINKER_LINKER_DEVNULL_H_
      15             : 
      16             : #if defined(CONFIG_LINKER_DEVNULL_MEMORY)
      17             : 
      18             : #if defined(CONFIG_XIP)
      19             : #if (!defined(ROM_ADDR) && !defined(ROM_BASE)) || !defined(ROM_SIZE)
      20             : #error "ROM_SIZE, ROM_ADDR or ROM_BASE not defined"
      21             : #endif
      22             : #endif /* CONFIG_XIP */
      23             : 
      24             : #if (!defined(RAM_ADDR) && !defined(RAM_BASE)) || !defined(RAM_SIZE)
      25             : #error "RAM_SIZE, RAM_ADDR or RAM_BASE not defined"
      26             : #endif
      27             : 
      28             : #if defined(CONFIG_XIP) && !defined(ROM_ADDR)
      29             : #define ROM_ADDR ROM_BASE
      30             : #endif
      31             : 
      32             : #if !defined(RAM_ADDR)
      33             : #define RAM_ADDR RAM_BASE
      34             : #endif
      35             : 
      36             : #define ROM_END_ADDR (ROM_ADDR + ROM_SIZE)
      37             : #define DEVNULL_SIZE CONFIG_LINKER_DEVNULL_MEMORY_SIZE
      38             : #define ROM_DEVNULL_END_ADDR (ROM_END_ADDR + DEVNULL_SIZE)
      39             : #define MAX_ADDR UINT32_MAX
      40             : 
      41             : /* Determine where to put the devnull region. It should be adjacent to the ROM
      42             :  * region. If ROM starts after RAM or the distance between ROM and RAM is big
      43             :  * enough to fit the devnull region then devnull region is placed just after
      44             :  * the ROM region. If it cannot be done then the devnull region is placed before
      45             :  * the ROM region. It is possible that the devnull region cannot be placed
      46             :  * adjacent to the ROM (e.g. ROM starts at 0 and RAM follows ROM). In that
      47             :  * case compilation fails and the devnull region is not supported in that
      48             :  * configuration.
      49             :  */
      50             : #if !defined(CONFIG_XIP)
      51             : 
      52             : #if RAM_ADDR >= DEVNULL_SIZE
      53             : #define DEVNULL_ADDR (RAM_ADDR - DEVNULL_SIZE)
      54             : #else
      55             : #define DEVNULL_ADDR (RAM_ADDR + RAM_SIZE)
      56             : #endif
      57             : 
      58             : #else /* CONFIG_XIP */
      59             : 
      60             : #if ((ROM_ADDR > RAM_ADDR) && ((MAX_ADDR - ROM_END_ADDR) >= DEVNULL_SIZE)) || \
      61             :         ((ROM_END_ADDR + DEVNULL_SIZE) <= RAM_ADDR)
      62             : #define DEVNULL_ADDR ROM_END_ADDR
      63             : #elif ROM_ADDR > DEVNULL_SIZE
      64             : #define DEVNULL_ADDR (ROM_ADDR - DEVNULL_SIZE)
      65             : #else
      66             : #error "Cannot place devnull segment adjacent to ROM region."
      67             : #endif
      68             : 
      69             : #endif /* CONFIG_XIP */
      70             : 
      71             : #define DEVNULL_REGION DEVNULL_ROM
      72             : 
      73             : #endif /* CONFIG_LINKER_DEVNULL_MEMORY */
      74             : 
      75             : #endif /* ZEPHYR_INCLUDE_LINKER_LINKER_DEVNULL_H_ */