/**************************************************************************** * boards/arm/sam34/sam3u-ek/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 * * 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 * under the License. * ****************************************************************************/ /* The ATSAM3U4E has 256KB of FLASH beginning at address 0x0008:0000, * 32KB of SRAM beginning at address 0x2000:0000, and 16Kb of SRAM beginning * at address 0x2008:000 (used only for heap). When booting from FLASH, * FLASH memory is aliased to address 0x0000:0000 where the code expects to * begin execution by jumping to the entry point in the 0x0800:0000 address * range. * * For MPU support, the kernel-mode NuttX section is assumed to be 64KB of * FLASH and 4KB of SRAM. That, of course, can be optimized as needed (See * also boards/open1788/scripts/kernel-space.ld). * * 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 128KB at it would have to be positioned at * 0x000a0000. 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 16Kb SRAM region is as follows: * * 0x20000 0000: Kernel .data region. Typical size: 0.1KB * ------- ---- Kernel .bss region. Typical size: 1.8KB * ------- ---- Kernel IDLE thread stack (approximate). Size is * determined by CONFIG_IDLETHREAD_STACKSIZE and * adjustments for alignment. Typical is 1KB. * ------- ---- Padded to 4KB * 0x20000 1000: User .data region. Size is variable. * ------- ---- User .bss region Size is variable. * ------- ---- Beginning of kernel heap. Size determined by * CONFIG_MM_KERNEL_HEAPSIZE. * ------- ---- Beginning of user heap. Can vary with other settings. * 0x20000 8000: End+1 of CPU RAM */ MEMORY { /* 256Kb FLASH */ kflash (rx) : ORIGIN = 0x00080000, LENGTH = 64K uflash (rx) : ORIGIN = 0x00090000, LENGTH = 64K xflash (rx) : ORIGIN = 0x000a0000, LENGTH = 128K /* 32Kb SRAM */ ksram1 (rwx) : ORIGIN = 0x20000000, LENGTH = 4K usram1 (rwx) : ORIGIN = 0x20001000, LENGTH = 4K xsram1 (rwx) : ORIGIN = 0x20002000, LENGTH = 24K /* 16Kb SRAM */ sram2 (rwx) : ORIGIN = 0x20080000, LENGTH = 16K }