Files
Upsilon/ion/test/external_flash_tests.ld
2019-04-18 09:51:22 +02:00

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/* Linker script
* The role of this script is to take all the object files built by the compiler
* and produce a single binary suitable for execution.
* Without an explicit linker script, the linker will produce a binary file that
* would not match some of our requirements (for example, we want the code to be
* written at a specific address (in Flash ROM) and the data at another. */
/* Let's instruct the linker about our memory layout.
* This will let us use shortcuts such as ">INTERNAL_FLASH" to ask for a given section to
* be stored in Flash. */
MEMORY {
INTERNAL_FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 64K
SRAM (rw) : ORIGIN = 0x20000000, LENGTH = 256K
}
STACK_SIZE = 32K;
SECTIONS {
.isr_vector_table ORIGIN(INTERNAL_FLASH) : {
/* When booting, the STM32F412 fetches the content of address 0x0, and
* extracts from it various key infos: the initial value of the PC register
* (program counter), the initial value of the stack pointer, and various
* entry points to interrupt service routines. This data is called the ISR
* vector table.
*
* Note that address 0x0 is always an alias. It points to the beginning of
* Flash, SRAM, or integrated bootloader depending on the boot mode chosen.
* (This mode is chosen by setting the BOOTn pins on the chip).
*
* We're generating the ISR vector table in code because it's very
* convenient: using function pointers, we can easily point to the service
* routine for each interrupt. */
_isr_start = .;
KEEP(*(.isr_vector_table))
} >INTERNAL_FLASH
.header : {
KEEP(*(.header))
} >INTERNAL_FLASH
.text.internal : {
. = ALIGN(4);
*(.text)
*(.text.*)
} >INTERNAL_FLASH
.rodata.internal : {
. = ALIGN(4);
*(.rodata)
*(.rodata.*)
} >INTERNAL_FLASH
.init_array : {
. = ALIGN(4);
_init_array_start = .;
KEEP (*(.init_array*))
_init_array_end = .;
} >INTERNAL_FLASH
.data : {
/* The data section is written to Flash but linked as if it were in RAM.
*
* This is required because its initial value matters (so it has to be in
* persistant memory in the first place), but it is a R/W area of memory
* so it will have to live in RAM upon execution (in linker lingo, that
* translates to the data section having a LMA in Flash and a VMA in RAM).
*
* This means we'll have to copy it from Flash to RAM on initialization.
* To do this, we'll need to know the source location of the data section
* (in Flash), the target location (in RAM), and the size of the section.
* That's why we're defining three symbols that we'll use in the initial-
* -ization routine. */
. = ALIGN(4);
_data_section_start_flash = LOADADDR(.data);
_data_section_start_ram = .;
*(.data)
*(.data.*)
_data_section_end_ram = .;
} >SRAM AT> INTERNAL_FLASH
.bss : {
/* The bss section contains data for all uninitialized variables
* So like the .data section, it will go in RAM, but unlike the data section
* we don't care at all about an initial value.
*
* Before execution, crt0 will erase that section of memory though, so we'll
* need pointers to the beginning and end of this section. */
. = ALIGN(4);
_bss_section_start_ram = .;
*(.bss)
*(.bss.*)
/* The compiler may choose to allocate uninitialized global variables as
* COMMON blocks. This can be disabled with -fno-common if needed. */
*(COMMON)
_bss_section_end_ram = .;
} >SRAM
.heap : {
_heap_start = .;
/* Note: We don't increment "." here, we set it. */
. = (ORIGIN(SRAM) + LENGTH(SRAM) - STACK_SIZE);
_heap_end = .;
} >SRAM
.stack : {
. = ALIGN(8);
_stack_end = .;
. += (STACK_SIZE - 8);
. = ALIGN(8);
_stack_start = .;
} >SRAM
}