-
-
Notifications
You must be signed in to change notification settings - Fork 11
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
1 changed file
with
303 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,303 @@ | ||
/* Based on GCC ARM embedded samples. | ||
Defines the following symbols for use by code: | ||
__exidx_start | ||
__exidx_end | ||
__etext | ||
__data_start__ | ||
__preinit_array_start | ||
__preinit_array_end | ||
__init_array_start | ||
__init_array_end | ||
__fini_array_start | ||
__fini_array_end | ||
__data_end__ | ||
__bss_start__ | ||
__bss_end__ | ||
__end__ | ||
end | ||
__HeapLimit | ||
__StackLimit | ||
__StackTop | ||
__stack (== StackTop) | ||
*/ | ||
|
||
MEMORY | ||
{ | ||
INCLUDE "pico_flash_region.ld" | ||
RAM(rwx) : ORIGIN = 0x20000000, LENGTH = 508k | ||
SCRATCH_X(rwx) : ORIGIN = 0x2007f000, LENGTH = 4k | ||
SCRATCH_Y(rwx) : ORIGIN = 0x20080000, LENGTH = 8k | ||
} | ||
|
||
ENTRY(_entry_point) | ||
|
||
SECTIONS | ||
{ | ||
.flash_begin : { | ||
__flash_binary_start = .; | ||
} > FLASH | ||
|
||
/* The bootrom will enter the image at the point indicated in your | ||
IMAGE_DEF, which is usually the reset handler of your vector table. | ||
|
||
The debugger will use the ELF entry point, which is the _entry_point | ||
symbol, and in our case is *different from the bootrom's entry point.* | ||
This is used to go back through the bootrom on debugger launches only, | ||
to perform the same initial flash setup that would be performed on a | ||
cold boot. | ||
*/ | ||
|
||
.text : { | ||
__logical_binary_start = .; | ||
KEEP (*(.vectors)) | ||
KEEP (*(.binary_info_header)) | ||
__binary_info_header_end = .; | ||
KEEP (*(.embedded_block)) | ||
__embedded_block_end = .; | ||
KEEP (*(.reset)) | ||
/* TODO revisit this now memset/memcpy/float in ROM */ | ||
/* bit of a hack right now to exclude all floating point and time critical (e.g. memset, memcpy) code from | ||
* FLASH ... we will include any thing excluded here in .data below by default */ | ||
*(.init) | ||
*libgcc.a:cmse_nonsecure_call.o | ||
*(EXCLUDE_FILE(*libgcc.a: *libc.a:*lib_a-mem*.o *libm.a:) .text*) | ||
*(.fini) | ||
/* Pull all c'tors into .text */ | ||
*crtbegin.o(.ctors) | ||
*crtbegin?.o(.ctors) | ||
*(EXCLUDE_FILE(*crtend?.o *crtend.o) .ctors) | ||
*(SORT(.ctors.*)) | ||
*(.ctors) | ||
/* Followed by destructors */ | ||
*crtbegin.o(.dtors) | ||
*crtbegin?.o(.dtors) | ||
*(EXCLUDE_FILE(*crtend?.o *crtend.o) .dtors) | ||
*(SORT(.dtors.*)) | ||
*(.dtors) | ||
|
||
. = ALIGN(4); | ||
/* preinit data */ | ||
PROVIDE_HIDDEN (__preinit_array_start = .); | ||
KEEP(*(SORT(.preinit_array.*))) | ||
KEEP(*(.preinit_array)) | ||
PROVIDE_HIDDEN (__preinit_array_end = .); | ||
|
||
. = ALIGN(4); | ||
/* init data */ | ||
PROVIDE_HIDDEN (__init_array_start = .); | ||
KEEP(*(SORT(.init_array.*))) | ||
KEEP(*(.init_array)) | ||
PROVIDE_HIDDEN (__init_array_end = .); | ||
|
||
. = ALIGN(4); | ||
/* finit data */ | ||
PROVIDE_HIDDEN (__fini_array_start = .); | ||
*(SORT(.fini_array.*)) | ||
*(.fini_array) | ||
PROVIDE_HIDDEN (__fini_array_end = .); | ||
|
||
*(.eh_frame*) | ||
. = ALIGN(4); | ||
} > FLASH | ||
|
||
/* Note the boot2 section is optional, and should be discarded if there is | ||
no reference to it *inside* the binary, as it is not called by the | ||
bootrom. (The bootrom performs a simple best-effort XIP setup and | ||
leaves it to the binary to do anything more sophisticated.) However | ||
there is still a size limit of 256 bytes, to ensure the boot2 can be | ||
stored in boot RAM. | ||
|
||
Really this is a "XIP setup function" -- the name boot2 is historic and | ||
refers to its dual-purpose on RP2040, where it also handled vectoring | ||
from the bootrom into the user image. | ||
*/ | ||
|
||
.boot2 : { | ||
__boot2_start__ = .; | ||
*(.boot2) | ||
__boot2_end__ = .; | ||
} > FLASH | ||
|
||
ASSERT(__boot2_end__ - __boot2_start__ <= 256, | ||
"ERROR: Pico second stage bootloader must be no more than 256 bytes in size") | ||
|
||
.rodata : { | ||
*(EXCLUDE_FILE(*libgcc.a: *libc.a:*lib_a-mem*.o *libm.a:) .rodata*) | ||
*(.srodata*) | ||
. = ALIGN(4); | ||
*(SORT_BY_ALIGNMENT(SORT_BY_NAME(.flashdata*))) | ||
. = ALIGN(4); | ||
} > FLASH | ||
|
||
.ARM.extab : | ||
{ | ||
*(.ARM.extab* .gnu.linkonce.armextab.*) | ||
} > FLASH | ||
|
||
__exidx_start = .; | ||
.ARM.exidx : | ||
{ | ||
*(.ARM.exidx* .gnu.linkonce.armexidx.*) | ||
} > FLASH | ||
__exidx_end = .; | ||
|
||
/* Machine inspectable binary information */ | ||
. = ALIGN(4); | ||
__binary_info_start = .; | ||
.binary_info : | ||
{ | ||
KEEP(*(.binary_info.keep.*)) | ||
*(.binary_info.*) | ||
} > FLASH | ||
__binary_info_end = .; | ||
. = ALIGN(4); | ||
|
||
.ram_vector_table (NOLOAD): { | ||
*(.ram_vector_table) | ||
} > RAM | ||
|
||
.uninitialized_data (NOLOAD): { | ||
. = ALIGN(4); | ||
*(.uninitialized_data*) | ||
} > RAM | ||
|
||
.data : { | ||
__data_start__ = .; | ||
*(vtable) | ||
|
||
*(.time_critical*) | ||
|
||
/* remaining .text and .rodata; i.e. stuff we exclude above because we want it in RAM */ | ||
*(.text*) | ||
. = ALIGN(4); | ||
*(.rodata*) | ||
. = ALIGN(4); | ||
|
||
*(.data*) | ||
*(.sdata*) | ||
|
||
. = ALIGN(4); | ||
*(.after_data.*) | ||
. = ALIGN(4); | ||
/* preinit data */ | ||
PROVIDE_HIDDEN (__mutex_array_start = .); | ||
KEEP(*(SORT(.mutex_array.*))) | ||
KEEP(*(.mutex_array)) | ||
PROVIDE_HIDDEN (__mutex_array_end = .); | ||
|
||
*(.jcr) | ||
. = ALIGN(4); | ||
} > RAM AT> FLASH | ||
|
||
.tdata : { | ||
. = ALIGN(4); | ||
*(.tdata .tdata.* .gnu.linkonce.td.*) | ||
/* All data end */ | ||
__tdata_end = .; | ||
} > RAM AT> FLASH | ||
PROVIDE(__data_end__ = .); | ||
|
||
/* __etext is (for backwards compatibility) the name of the .data init source pointer (...) */ | ||
__etext = LOADADDR(.data); | ||
|
||
.tbss (NOLOAD) : { | ||
. = ALIGN(4); | ||
__bss_start__ = .; | ||
__tls_base = .; | ||
*(.tbss .tbss.* .gnu.linkonce.tb.*) | ||
*(.tcommon) | ||
|
||
__tls_end = .; | ||
} > RAM | ||
|
||
.bss (NOLOAD) : { | ||
. = ALIGN(4); | ||
__tbss_end = .; | ||
|
||
*(SORT_BY_ALIGNMENT(SORT_BY_NAME(.bss*))) | ||
*(COMMON) | ||
PROVIDE(__global_pointer$ = . + 2K); | ||
*(.sbss*) | ||
. = ALIGN(4); | ||
__bss_end__ = .; | ||
} > RAM | ||
|
||
.heap (NOLOAD): | ||
{ | ||
__end__ = .; | ||
end = __end__; | ||
KEEP(*(.heap*)) | ||
/* historically on GCC sbrk was growing past __HeapLimit to __StackLimit, however | ||
to be more compatible, we now set __HeapLimit explicitly to where the end of the heap is */ | ||
. = ORIGIN(RAM) + LENGTH(RAM); | ||
__HeapLimit = .; | ||
} > RAM | ||
|
||
/* Start and end symbols must be word-aligned */ | ||
.scratch_x : { | ||
__scratch_x_start__ = .; | ||
*(.scratch_x.*) | ||
. = ALIGN(4); | ||
__scratch_x_end__ = .; | ||
} > SCRATCH_X AT > FLASH | ||
__scratch_x_source__ = LOADADDR(.scratch_x); | ||
|
||
.scratch_y : { | ||
__scratch_y_start__ = .; | ||
*(.scratch_y.*) | ||
. = ALIGN(4); | ||
__scratch_y_end__ = .; | ||
} > SCRATCH_Y AT > FLASH | ||
__scratch_y_source__ = LOADADDR(.scratch_y); | ||
|
||
/* .stack*_dummy section doesn't contains any symbols. It is only | ||
* used for linker to calculate size of stack sections, and assign | ||
* values to stack symbols later | ||
* | ||
* stack1 section may be empty/missing if platform_launch_core1 is not used */ | ||
|
||
/* by default we put core 0 stack at the end of scratch Y, so that if core 1 | ||
* stack is not used then all of SCRATCH_X is free. | ||
*/ | ||
.stack1_dummy (NOLOAD): | ||
{ | ||
*(.stack1*) | ||
} > SCRATCH_X | ||
.stack_dummy (NOLOAD): | ||
{ | ||
KEEP(*(.stack*)) | ||
} > SCRATCH_Y | ||
|
||
.flash_end : { | ||
KEEP(*(.embedded_end_block*)) | ||
PROVIDE(__flash_binary_end = .); | ||
} > FLASH =0xaa | ||
|
||
/* stack limit is poorly named, but historically is maximum heap ptr */ | ||
__StackLimit = ORIGIN(RAM) + LENGTH(RAM); | ||
__StackOneTop = ORIGIN(SCRATCH_X) + LENGTH(SCRATCH_X); | ||
__StackTop = ORIGIN(SCRATCH_Y) + LENGTH(SCRATCH_Y); | ||
__StackOneBottom = __StackOneTop - SIZEOF(.stack1_dummy); | ||
__StackBottom = __StackTop - SIZEOF(.stack_dummy); | ||
PROVIDE(__stack = __StackTop); | ||
|
||
/* picolibc and LLVM */ | ||
PROVIDE (__heap_start = __end__); | ||
PROVIDE (__heap_end = __HeapLimit); | ||
PROVIDE( __tls_align = MAX(ALIGNOF(.tdata), ALIGNOF(.tbss)) ); | ||
PROVIDE( __tls_size_align = (__tls_size + __tls_align - 1) & ~(__tls_align - 1)); | ||
PROVIDE( __arm32_tls_tcb_offset = MAX(8, __tls_align) ); | ||
|
||
/* llvm-libc */ | ||
PROVIDE (_end = __end__); | ||
PROVIDE (__llvm_libc_heap_limit = __HeapLimit); | ||
|
||
/* Check if data + heap + stack exceeds RAM limit */ | ||
ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed") | ||
|
||
ASSERT( __binary_info_header_end - __logical_binary_start <= 1024, "Binary info must be in first 1024 bytes of the binary") | ||
ASSERT( __embedded_block_end - __logical_binary_start <= 4096, "Embedded block must be in first 4096 bytes of the binary") | ||
|
||
/* todo assert on extra code */ | ||
} | ||
|