nuttx/boards/arm/lpc17xx_40xx/lpc4088-devkit/scripts/memory.ld

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 * boards/arm/lpc17xx_40xx/lpc4088-devkit/scripts/memory.ld
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
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 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
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/* The LPC4088 has 512Kb of FLASH beginning at address 0x0000:0000 and
 * 96KB of total SRAM: 64KB of SRAM in the CPU block beginning at address
 * 0x10000000 and 32Kb of Peripheral SRAM in two banks, 8KB at addresses
 * 0x20000000 bank0 first and 8KB at 0x20002000 at bank0 second. And 16KB
 * at 0x20004000 on bank1.
 *
 * For MPU support, the kernel-mode NuttX section is assumed to be 256KB of
 * FLASH and 4KB of SRAM.  That, of course, can be optimized as needed (See
 * also boards/arm/lpc17xx_40xx/lpc4088-devkit/scripts/kernel-space.ld);
 * 256KB is probably much more than is needed by the RTOS!
 * That size is selected only because it is available due to alignment
 * issues for the user space FLASH memory.
 *
 * Alignment of the user space FLASH partition is a critical factor: The
 * user space FLASH partition will be spanned with a single region of size
 * 2**n bytes.  The alignment of the user-space region must be the same.  As
 * a consequence, as the user-space increases in size, the alignment
 * requirement also increases.
 *
 * This alignment requirement means that the largest user space FLASH region
 * you can have will be 256KB at it would have to be positioned at
 * 0x00400000.  If you change this address, don't forget to change the
 * CONFIG_NUTTX_USERSPACE configuration setting to match and to modify
 * the check in kernel/userspace.c.
 *
 * For the same reasons, the maximum size of the SRAM mapping is limited to
 * 4KB.  Both of these alignment limitations could be reduced by using
 * multiple regions to map the FLASH/SDRAM range or perhaps with some
 * clever use of subregions.
 *
 * A detailed memory map for the 64KB CPU SRAM region is as follows:
 *
 *   0x10000 0000:  Kernel .data region.  Typical size: 0.1KB
 *   ------- ----   Kernel .bss  region.  Typical size: 1.8KB
 *   0x10000 0800:  Kernel IDLE thread stack (approximate).  Size is
 *                  determined by CONFIG_IDLETHREAD_STACKSIZE and
 *                  adjustments for alignment.  Typical is 1KB.
 *   ------- ----   Padded to 4KB
 *   0x10000 1000:  User .data region.  Size is variable.
 *   ------- ----   User .bss region  Size is variable.
 *   ------- ----   Beginning of kernel heap.  Size determined by
 *                  CONFIG_MM_KERNEL_HEAPSIZE.
 *   0x10000 8000:  Beginning of user heap.  Can vary with other settings.
 *   0x10001 0000:  End+1 of CPU RAM
 */

MEMORY
{
  /* 256Kb FLASH */

  kflash (rx)      : ORIGIN = 0x00000000, LENGTH = 256K /* More than needed */
  uflash (rx)      : ORIGIN = 0x00040000, LENGTH = 256K

  /* 64Kb of SRAM in the CPU block */

  ksram (rwx)      : ORIGIN = 0x10000000, LENGTH = 4K   /* May include waste */
  usram (rwx)      : ORIGIN = 0x10001000, LENGTH = 4K
  xsram (rwx)      : ORIGIN = 0x10002000, LENGTH = 24K  /* All used as heap */

  /* Other peripheral memory (free, nothing is linked here) */

  ahbram8_b0a(rwx) : ORIGIN = 0x20000000, LENGTH = 8K
  ahbram8_b0b(rwx) : ORIGIN = 0x20002000, LENGTH = 8K
  ahbram16(rwx)    : ORIGIN = 0x20004000, LENGTH = 16K
}