Armando Montanez | 7009566 | 2020-01-09 14:25:04 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2020 The Pigweed Authors |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| 5 | * use this file except in compliance with the License. You may obtain a copy of |
| 6 | * the License at |
| 7 | * |
| 8 | * https://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 12 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 13 | * License for the specific language governing permissions and limitations under |
| 14 | * the License. |
| 15 | */ |
| 16 | |
| 17 | /* This relatively simplified linker script will work with many ARMv7-M cores |
| 18 | * that have on-board memory-mapped RAM and FLASH. For more complex projects and |
| 19 | * devices, it's possible this linker script will not be sufficient as-is. |
| 20 | * |
| 21 | * This linker script is likely not suitable for a project with a bootloader. |
| 22 | */ |
| 23 | |
| 24 | /* Provide useful error messages when required configurations are not set. */ |
Armando Montanez | 9221213 | 2020-01-16 15:03:20 -0800 | [diff] [blame] | 25 | #ifndef PW_BOOT_VECTOR_TABLE_BEGIN |
| 26 | #error "PW_BOOT_VECTOR_TABLE_BEGIN is not defined, and is required to use pw_boot_armv7m" |
| 27 | #endif // PW_BOOT_VECTOR_TABLE_BEGIN |
Armando Montanez | 7009566 | 2020-01-09 14:25:04 -0800 | [diff] [blame] | 28 | |
Armando Montanez | 9221213 | 2020-01-16 15:03:20 -0800 | [diff] [blame] | 29 | #ifndef PW_BOOT_VECTOR_TABLE_SIZE |
| 30 | #error "PW_BOOT_VECTOR_TABLE_SIZE is not defined, and is required to use pw_boot_armv7m" |
| 31 | #endif // PW_BOOT_VECTOR_TABLE_SIZE |
Armando Montanez | 7009566 | 2020-01-09 14:25:04 -0800 | [diff] [blame] | 32 | |
| 33 | #ifndef PW_BOOT_FLASH_BEGIN |
| 34 | #error "PW_BOOT_FLASH_BEGIN is not defined, and is required to use pw_boot_armv7m" |
| 35 | #endif // PW_BOOT_FLASH_BEGIN |
| 36 | |
| 37 | #ifndef PW_BOOT_FLASH_SIZE |
| 38 | #error "PW_BOOT_FLASH_SIZE is not defined, and is required to use pw_boot_armv7m" |
| 39 | #endif // PW_BOOT_FLASH_SIZE |
| 40 | |
| 41 | #ifndef PW_BOOT_RAM_BEGIN |
| 42 | #error "PW_BOOT_RAM_BEGIN is not defined, and is required to use pw_boot_armv7m" |
| 43 | #endif // PW_BOOT_RAM_BEGIN |
| 44 | |
| 45 | #ifndef PW_BOOT_RAM_SIZE |
| 46 | #error "PW_BOOT_RAM_SIZE is not defined, and is required to use pw_boot_armv7m" |
| 47 | #endif // PW_BOOT_RAM_SIZE |
| 48 | |
| 49 | #ifndef PW_BOOT_HEAP_SIZE |
| 50 | #error "PW_BOOT_HEAP_SIZE is not defined, and is required to use pw_boot_armv7m" |
| 51 | #endif // PW_BOOT_HEAP_SIZE |
| 52 | |
| 53 | #ifndef PW_BOOT_MIN_STACK_SIZE |
| 54 | #error "PW_BOOT_MIN_STACK_SIZE is not defined, and is required to use pw_boot_armv7m" |
| 55 | #endif // PW_BOOT_MIN_STACK_SIZE |
| 56 | |
| 57 | |
| 58 | /* Note: This technically doesn't set the firmware's entry point. Setting the |
| 59 | * firmware entry point is done by setting vector_table[1] |
| 60 | * (Reset_Handler). However, this DOES tell the compiler how to optimize |
| 61 | * when --gc-sections is enabled. |
| 62 | */ |
| 63 | ENTRY(pw_BootEntry) |
| 64 | |
| 65 | MEMORY |
| 66 | { |
| 67 | /* TODO(pwbug/57): Make it possible for projects to freely customize |
| 68 | * memory regions. |
| 69 | */ |
| 70 | |
| 71 | /* Vector Table (typically in flash) */ |
Armando Montanez | 9221213 | 2020-01-16 15:03:20 -0800 | [diff] [blame] | 72 | VECTOR_TABLE(rx) : \ |
| 73 | ORIGIN = PW_BOOT_VECTOR_TABLE_BEGIN, \ |
| 74 | LENGTH = PW_BOOT_VECTOR_TABLE_SIZE |
Armando Montanez | 7009566 | 2020-01-09 14:25:04 -0800 | [diff] [blame] | 75 | /* Internal Flash */ |
| 76 | FLASH(rx) : \ |
| 77 | ORIGIN = PW_BOOT_FLASH_BEGIN, \ |
| 78 | LENGTH = PW_BOOT_FLASH_SIZE |
| 79 | /* Internal SRAM */ |
| 80 | RAM(rwx) : \ |
| 81 | ORIGIN = PW_BOOT_RAM_BEGIN, \ |
| 82 | LENGTH = PW_BOOT_RAM_SIZE |
| 83 | } |
| 84 | |
| 85 | SECTIONS |
| 86 | { |
| 87 | /* This is the link-time vector table. If used, the VTOR (Vector Table Offset |
| 88 | * Register) MUST point to this memory location in order to be used. This can |
| 89 | * be done by ensuring this section exists at the default location of the VTOR |
| 90 | * so it's used on reset, or by explicitly setting the VTOR in a bootloader |
| 91 | * manually to point to &pw_vector_table_addr before interrupts are enabled. |
| 92 | */ |
| 93 | .vector_table : ALIGN(512) |
| 94 | { |
| 95 | pw_vector_table_addr = .; |
| 96 | KEEP(*(.vector_table)) |
Armando Montanez | 9221213 | 2020-01-16 15:03:20 -0800 | [diff] [blame] | 97 | } >VECTOR_TABLE |
Armando Montanez | 7009566 | 2020-01-09 14:25:04 -0800 | [diff] [blame] | 98 | |
| 99 | /* Main executable code. */ |
| 100 | .code : ALIGN(8) |
| 101 | { |
| 102 | . = ALIGN(8); |
| 103 | /* Application code. */ |
| 104 | *(.text) |
| 105 | *(.text*) |
| 106 | KEEP(*(.init)) |
| 107 | KEEP(*(.fini)) |
| 108 | |
| 109 | . = ALIGN(8); |
| 110 | /* Constants.*/ |
| 111 | *(.rodata) |
| 112 | *(.rodata*) |
| 113 | |
| 114 | /* .preinit_array, .init_array, .fini_array are used by libc. |
| 115 | * Each section is a list of function pointers that are called pre-main and |
| 116 | * post-exit for object initialization and tear-down. |
| 117 | * Since the region isn't explicitly referenced, specify KEEP to prevent |
| 118 | * link-time garbage collection. SORT is used for sections that have strict |
| 119 | * init/de-init ordering requirements. */ |
| 120 | . = ALIGN(8); |
| 121 | PROVIDE_HIDDEN(__preinit_array_start = .); |
| 122 | KEEP(*(.preinit_array*)) |
| 123 | PROVIDE_HIDDEN(__preinit_array_end = .); |
| 124 | |
| 125 | PROVIDE_HIDDEN(__init_array_start = .); |
| 126 | KEEP(*(SORT(.init_array.*))) |
| 127 | KEEP(*(.init_array*)) |
| 128 | PROVIDE_HIDDEN(__init_array_end = .); |
| 129 | |
| 130 | PROVIDE_HIDDEN(__fini_array_start = .); |
| 131 | KEEP(*(SORT(.fini_array.*))) |
| 132 | KEEP(*(.fini_array*)) |
| 133 | PROVIDE_HIDDEN(__fini_array_end = .); |
| 134 | } >FLASH |
| 135 | |
| 136 | /* Used by unwind-arm/ */ |
| 137 | .ARM : ALIGN(8) { |
| 138 | __exidx_start = .; |
| 139 | *(.ARM.exidx*) |
| 140 | __exidx_end = .; |
| 141 | } >FLASH |
| 142 | |
| 143 | /* Explicitly initialized global and static data. (.data)*/ |
| 144 | .static_init_ram : ALIGN(8) |
| 145 | { |
| 146 | *(.data) |
| 147 | *(.data*) |
| 148 | . = ALIGN(8); |
| 149 | } >RAM AT> FLASH |
| 150 | |
| 151 | /* Zero initialized global/static data. (.bss) |
| 152 | * This section is zero initialized in pw_BootEntry(). */ |
| 153 | .zero_init_ram : ALIGN(8) |
| 154 | { |
| 155 | *(.bss) |
| 156 | *(.bss*) |
| 157 | *(COMMON) |
| 158 | . = ALIGN(8); |
| 159 | } >RAM |
| 160 | |
| 161 | .heap : ALIGN(8) |
| 162 | { |
| 163 | pw_heap_low_addr = .; |
| 164 | . = . + PW_BOOT_HEAP_SIZE; |
| 165 | . = ALIGN(8); |
| 166 | pw_heap_high_addr = .; |
| 167 | } >RAM |
| 168 | |
| 169 | /* Link-time check for stack overlaps. */ |
| 170 | .stack (NOLOAD) : ALIGN(8) |
| 171 | { |
| 172 | /* Set the address that the main stack pointer should be initialized to. */ |
| 173 | pw_stack_low_addr = .; |
| 174 | HIDDEN(_stack_size = ORIGIN(RAM) + LENGTH(RAM) - .); |
| 175 | /* Align the stack to a lower address to ensure it isn't out of range. */ |
| 176 | HIDDEN(_stack_high = (. + _stack_size) & ~0x7); |
| 177 | ASSERT(_stack_high - . >= PW_BOOT_MIN_STACK_SIZE, |
| 178 | "Error: Not enough RAM for desired minimum stack size."); |
| 179 | . = _stack_high; |
| 180 | pw_stack_high_addr = .; |
| 181 | } >RAM |
| 182 | } |
| 183 | |
| 184 | /* Symbols used by core_init.c: */ |
| 185 | /* Start of .static_init_ram in FLASH. */ |
| 186 | _pw_static_init_flash_start = LOADADDR(.static_init_ram); |
| 187 | |
| 188 | /* Region of .static_init_ram in RAM. */ |
| 189 | _pw_static_init_ram_start = ADDR(.static_init_ram); |
| 190 | _pw_static_init_ram_end = _pw_static_init_ram_start + SIZEOF(.static_init_ram); |
| 191 | |
| 192 | /* Region of .zero_init_ram. */ |
| 193 | _pw_zero_init_ram_start = ADDR(.zero_init_ram); |
| 194 | _pw_zero_init_ram_end = _pw_zero_init_ram_start + SIZEOF(.zero_init_ram); |
| 195 | |
| 196 | /* arm-none-eabi expects `end` symbol to point to start of heap for sbrk. */ |
| 197 | PROVIDE(end = _pw_zero_init_ram_end); |