esp-idf/components/esp32/ld/esp32.common.ld
Hrishikesh Dhayagude f610249bdd Reclaim BT/BTDM BSS and Data in bluetooth memory release function
1. Modify esp_bt_controller_mem_release() to release BTDM BSS and Data to heap if
ESP_BT_MODE_BTDM mode is passed to it
2. Add a new API esp_bt_mem_release() which internally calls
esp_bt_controller_mem_release() with the provided mode and then if mode
is ESP_BT_MODE_BTDM, releases BT BSS and Data to heap.

Background:
For Wi-Fi and BT/BLE applications, for e.g. the usecase is like when
Bluetooth is used for provisioning and once the device is connected to the Wi-Fi
AP, we can turn off Bluetooth completely. In such scenarios, it should be possible to
reclaim all the memory of Bluetooth. Although, currently this does not
happen.

Experiment:
Made the following modifications to examples/bluetooth/gatt_server :
1. Added support of simple_wifi to it
2. Moved all the bluetooth related code under CONFIG_BT_ENABLED config
option
3. Calculated the free heap in 2 similar scenarios:
   i. Disabled BT (CONFIG_BT_ENABLED undefined) and checked the free
heap after STA connected
   ii. Kept BT enabled and disabled it after STA connected and checked
the free heap
Ideally, the numbers for i., ii. above should have been similar. But
there was a delta of almost 30-31K. (i. > ii.)
4. Through make size-components checked the common BSS for libbta.a and libbtdm_app.a
and found it to be almost 30K. Data is around 1K

Solution:
1. Modified the linker script to mark the BSS and Data for these libraries and
free it when ESP_BT_MODE_BTDM mode is passed to mem release APIs.
2. Verified that the free heap is comparable for i. and ii. above.

Note: It is known that once this is done, Bluetooth can only be used
again post reboot.

Signed-off-by: Hrishikesh Dhayagude <hrishi@espressif.com>
2018-07-20 11:33:26 +05:30

270 lines
7.5 KiB
Plaintext

/* Default entry point: */
ENTRY(call_start_cpu0);
SECTIONS
{
/* RTC fast memory holds RTC wake stub code,
including from any source file named rtc_wake_stub*.c
*/
.rtc.text :
{
. = ALIGN(4);
*(.rtc.literal .rtc.text)
*rtc_wake_stub*.o(.literal .text .literal.* .text.*)
} > rtc_iram_seg
/* RTC slow memory holds RTC wake stub
data/rodata, including from any source file
named rtc_wake_stub*.c
*/
.rtc.data :
{
_rtc_data_start = ABSOLUTE(.);
*(.rtc.data)
*(.rtc.rodata)
*rtc_wake_stub*.o(.data .rodata .data.* .rodata.* .bss .bss.*)
_rtc_data_end = ABSOLUTE(.);
} > rtc_slow_seg
/* RTC bss, from any source file named rtc_wake_stub*.c */
.rtc.bss (NOLOAD) :
{
_rtc_bss_start = ABSOLUTE(.);
*rtc_wake_stub*.o(.bss .bss.*)
*rtc_wake_stub*.o(COMMON)
_rtc_bss_end = ABSOLUTE(.);
} > rtc_slow_seg
/* This section holds data that should not be initialized at power up
and will be retained during deep sleep. The section located in
RTC SLOW Memory area. User data marked with RTC_NOINIT_ATTR will be placed
into this section. See the file "esp_attr.h" for more information.
*/
.rtc_noinit (NOLOAD):
{
. = ALIGN(4);
_rtc_noinit_start = ABSOLUTE(.);
*(.rtc_noinit .rtc_noinit.*)
. = ALIGN(4) ;
_rtc_noinit_end = ABSOLUTE(.);
} > rtc_slow_seg
/* Send .iram0 code to iram */
.iram0.vectors :
{
/* Vectors go to IRAM */
_init_start = ABSOLUTE(.);
/* Vectors according to builds/RF-2015.2-win32/esp108_v1_2_s5_512int_2/config.html */
. = 0x0;
KEEP(*(.WindowVectors.text));
. = 0x180;
KEEP(*(.Level2InterruptVector.text));
. = 0x1c0;
KEEP(*(.Level3InterruptVector.text));
. = 0x200;
KEEP(*(.Level4InterruptVector.text));
. = 0x240;
KEEP(*(.Level5InterruptVector.text));
. = 0x280;
KEEP(*(.DebugExceptionVector.text));
. = 0x2c0;
KEEP(*(.NMIExceptionVector.text));
. = 0x300;
KEEP(*(.KernelExceptionVector.text));
. = 0x340;
KEEP(*(.UserExceptionVector.text));
. = 0x3C0;
KEEP(*(.DoubleExceptionVector.text));
. = 0x400;
*(.*Vector.literal)
*(.UserEnter.literal);
*(.UserEnter.text);
. = ALIGN (16);
*(.entry.text)
*(.init.literal)
*(.init)
_init_end = ABSOLUTE(.);
/* This goes here, not at top of linker script, so addr2line finds it last,
and uses it in preference to the first symbol in IRAM */
_iram_start = ABSOLUTE(0);
} > iram0_0_seg
.iram0.text :
{
/* Code marked as runnning out of IRAM */
_iram_text_start = ABSOLUTE(.);
*(.iram1 .iram1.*)
*libfreertos.a:(.literal .text .literal.* .text.*)
*libheap.a:multi_heap.o(.literal .text .literal.* .text.*)
*libheap.a:multi_heap_poisoning.o(.literal .text .literal.* .text.*)
*libesp32.a:panic.o(.literal .text .literal.* .text.*)
*libesp32.a:core_dump.o(.literal .text .literal.* .text.*)
*libapp_trace.a:(.literal .text .literal.* .text.*)
*libxtensa-debug-module.a:eri.o(.literal .text .literal.* .text.*)
*librtc.a:(.literal .text .literal.* .text.*)
*libsoc.a:(.literal .text .literal.* .text.*)
*libhal.a:(.literal .text .literal.* .text.*)
*libgcc.a:lib2funcs.o(.literal .text .literal.* .text.*)
*libspi_flash.a:spi_flash_rom_patch.o(.literal .text .literal.* .text.*)
*libgcov.a:(.literal .text .literal.* .text.*)
INCLUDE esp32.spiram.rom-functions-iram.ld
_iram_text_end = ABSOLUTE(.);
} > iram0_0_seg
.dram0.data :
{
_data_start = ABSOLUTE(.);
_bt_data_start = ABSOLUTE(.);
*libbt.a:(.data .data.*)
. = ALIGN (4);
_bt_data_end = ABSOLUTE(.);
_btdm_data_start = ABSOLUTE(.);
*libbtdm_app.a:(.data .data.*)
. = ALIGN (4);
_btdm_data_end = ABSOLUTE(.);
*(.data)
*(.data.*)
*(.gnu.linkonce.d.*)
*(.data1)
*(.sdata)
*(.sdata.*)
*(.gnu.linkonce.s.*)
*(.sdata2)
*(.sdata2.*)
*(.gnu.linkonce.s2.*)
*(.jcr)
*(.dram1 .dram1.*)
*libesp32.a:panic.o(.rodata .rodata.*)
*libphy.a:(.rodata .rodata.*)
*libsoc.a:rtc_clk.o(.rodata .rodata.*)
*libapp_trace.a:(.rodata .rodata.*)
*libgcov.a:(.rodata .rodata.*)
*libheap.a:multi_heap.o(.rodata .rodata.*)
*libheap.a:multi_heap_poisoning.o(.rodata .rodata.*)
INCLUDE esp32.spiram.rom-functions-dram.ld
_data_end = ABSOLUTE(.);
. = ALIGN(4);
} > dram0_0_seg
/*This section holds data that should not be initialized at power up.
The section located in Internal SRAM memory region. The macro _NOINIT
can be used as attribute to place data into this section.
See the esp_attr.h file for more information.
*/
.noinit (NOLOAD):
{
. = ALIGN(4);
_noinit_start = ABSOLUTE(.);
*(.noinit .noinit.*)
. = ALIGN(4) ;
_noinit_end = ABSOLUTE(.);
} > dram0_0_seg
/* Shared RAM */
.dram0.bss (NOLOAD) :
{
. = ALIGN (8);
_bss_start = ABSOLUTE(.);
_bt_bss_start = ABSOLUTE(.);
*libbt.a:(.bss .bss.* COMMON)
. = ALIGN (4);
_bt_bss_end = ABSOLUTE(.);
_btdm_bss_start = ABSOLUTE(.);
*libbtdm_app.a:(.bss .bss.* COMMON)
. = ALIGN (4);
_btdm_bss_end = ABSOLUTE(.);
*(.dynsbss)
*(.sbss)
*(.sbss.*)
*(.gnu.linkonce.sb.*)
*(.scommon)
*(.sbss2)
*(.sbss2.*)
*(.gnu.linkonce.sb2.*)
*(.dynbss)
*(.bss)
*(.bss.*)
*(.share.mem)
*(.gnu.linkonce.b.*)
*(COMMON)
. = ALIGN (8);
_bss_end = ABSOLUTE(.);
/* The heap starts right after end of this section */
_heap_start = ABSOLUTE(.);
} > dram0_0_seg
.flash.rodata :
{
_rodata_start = ABSOLUTE(.);
*(.rodata)
*(.rodata.*)
*(.irom1.text) /* catch stray ICACHE_RODATA_ATTR */
*(.gnu.linkonce.r.*)
*(.rodata1)
__XT_EXCEPTION_TABLE_ = ABSOLUTE(.);
*(.xt_except_table)
*(.gcc_except_table .gcc_except_table.*)
*(.gnu.linkonce.e.*)
*(.gnu.version_r)
. = (. + 3) & ~ 3;
__eh_frame = ABSOLUTE(.);
KEEP(*(.eh_frame))
. = (. + 7) & ~ 3;
/* C++ constructor and destructor tables, properly ordered: */
__init_array_start = ABSOLUTE(.);
KEEP (*crtbegin.o(.ctors))
KEEP (*(EXCLUDE_FILE (*crtend.o) .ctors))
KEEP (*(SORT(.ctors.*)))
KEEP (*(.ctors))
__init_array_end = ABSOLUTE(.);
KEEP (*crtbegin.o(.dtors))
KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
KEEP (*(SORT(.dtors.*)))
KEEP (*(.dtors))
/* C++ exception handlers table: */
__XT_EXCEPTION_DESCS_ = ABSOLUTE(.);
*(.xt_except_desc)
*(.gnu.linkonce.h.*)
__XT_EXCEPTION_DESCS_END__ = ABSOLUTE(.);
*(.xt_except_desc_end)
*(.dynamic)
*(.gnu.version_d)
_rodata_end = ABSOLUTE(.);
/* Literals are also RO data. */
_lit4_start = ABSOLUTE(.);
*(*.lit4)
*(.lit4.*)
*(.gnu.linkonce.lit4.*)
_lit4_end = ABSOLUTE(.);
. = ALIGN(4);
_thread_local_start = ABSOLUTE(.);
*(.tdata)
*(.tdata.*)
*(.tbss)
*(.tbss.*)
_thread_local_end = ABSOLUTE(.);
. = ALIGN(4);
} >drom0_0_seg
.flash.text :
{
_stext = .;
_text_start = ABSOLUTE(.);
*(.literal .text .literal.* .text.* .stub .gnu.warning .gnu.linkonce.literal.* .gnu.linkonce.t.*.literal .gnu.linkonce.t.*)
*(.irom0.text) /* catch stray ICACHE_RODATA_ATTR */
*(.fini.literal)
*(.fini)
*(.gnu.version)
_text_end = ABSOLUTE(.);
_etext = .;
/* Similar to _iram_start, this symbol goes here so it is
resolved by addr2line in preference to the first symbol in
the flash.text segment.
*/
_flash_cache_start = ABSOLUTE(0);
} >iram0_2_seg
}