the way of reducing softdevice resource consumption

RE: the way of reducing softdevice resource consumption

Gerbert Shnauer — Tue, 22 Dec 2015 11:31:06 GMT

OK, thank you, I've understood the source of the values.

RE: the way of reducing softdevice resource consumption

Hung Bui — Tue, 22 Dec 2015 09:31:50 GMT

@Gerbert: The configuration in the *.ld files in \components\softdevice\s130\toolchain\armgcc are wrong. I have reported it.

Please use the .ld file in the example folder if you are testing with the example. Or define your own based on your configuration, following what I described in the answer above.

RE: the way of reducing softdevice resource consumption

monpetit — Mon, 21 Dec 2015 23:10:32 GMT

Have you ever used these scripts in the real world?

Why do you suppose the linker scripts of examples are like these?

$ grep RAM examples/ble_peripheral/*/pca10028/s130/armgcc/*.ld | sed -e 's/.*armgcc\///'
ble_app_alert_notification_gcc_nrf51.ld:  RAM (rwx) :  ORIGIN = 0x20001f00, LENGTH = 0x6100
ble_app_ancs_c_gcc_nrf51.ld:  RAM (rwx) :  ORIGIN = 0x20001f00, LENGTH = 0x6100
ble_app_beacon_gcc_nrf51.ld:  RAM (rwx) :  ORIGIN = 0x20001860, LENGTH = 0x67a0
ble_app_bps_gcc_nrf51.ld:  RAM (rwx) :  ORIGIN = 0x20001f00, LENGTH = 0x6100
ble_app_cscs_gcc_nrf51.ld:  RAM (rwx) :  ORIGIN = 0x20001f00, LENGTH = 0x6100
ble_app_cts_c_gcc_nrf51.ld:  RAM (rwx) :  ORIGIN = 0x20001f00, LENGTH = 0x6100
ble_app_gls_gcc_nrf51.ld:  RAM (rwx) :  ORIGIN = 0x20001f00, LENGTH = 0x6100
...

RE: the way of reducing softdevice resource consumption

Gerbert Shnauer — Mon, 21 Dec 2015 20:38:43 GMT

Thank you very much. Tutorial would be very useful to understand architecture correctly.

RE: the way of reducing softdevice resource consumption

Gerbert Shnauer — Mon, 21 Dec 2015 20:30:00 GMT

$ grep RAM sdk_11.0.0/components/softdevice/s130/toolchain/armgcc/*.ld sdk_11.0.0/components/softdevice/s130/toolchain/armgcc/armgcc_s130_nrf51422_xxaa.ld: RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 0x4000

sdk_11.0.0/components/softdevice/s130/toolchain/armgcc/armgcc_s130_nrf51422_xxac.ld: RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 0x8000

sdk_11.0.0/components/softdevice/s130/toolchain/armgcc/armgcc_s130_nrf51822_xxaa.ld: RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 0x4000

sdk_11.0.0/components/softdevice/s130/toolchain/armgcc/armgcc_s130_nrf51822_xxab.ld: RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 0x4000

RE: the way of reducing softdevice resource consumption

Hung Bui — Mon, 21 Dec 2015 16:32:54 GMT

Hi Gerbert,

It's correct that the minimum RAM required for the S130 actually lower than what was on the S110 or S120.

The reason for that is that the RAM configured for S130 v2.x is configurable via the sd_ble_enable() function. This is because the number of central, peripheral and encrypted central link that you plan to handle is configurable.

On earlier softdevice version was fixed, for example the S110 support 1 peripheral links, S120 support 8 central links, S130 v1.x support 3 central links and 1 peripheral link. On S130 v2.x this is flexible. So if you just want the functionality of S110, you can configure the S130 to support only 1 peripheral link, this way you won't waste RAM on the S130.

Note 1: you can only save RAM, the flash size is fixed

Note 2: To be able to configure the RAM correctly, you should start first with a dummy RAM configuration, such as ORIGIN = 0x20001f00, LENGTH = 0x6100, and put 0x20001f00 into the p_app_ram_base parameter. Then you run in debug mode and add a breakpoint at the function. After you call the function, you can check the p_app_ram_base again and see what is the actual RAM requirement for the setup you choose. After that you can update the RAM configuration in KEIL.

We will publish a tutorial with more detail on how to do it soon.

RE: the way of reducing softdevice resource consumption

monpetit — Mon, 21 Dec 2015 15:15:10 GMT

Really? Then how much does the s130 consume RAM in SDK 11.0.0? Please show me the values.

RE: the way of reducing softdevice resource consumption

Gerbert Shnauer — Mon, 21 Dec 2015 09:53:40 GMT

Well, these values are not for the SoftDevice.

RE: the way of reducing softdevice resource consumption

monpetit — Sun, 20 Dec 2015 00:16:46 GMT

Hi Gerbert,

RAM usage of the SoftDevice in s130_nrf51_2.0.0-7.alpha is alreay reduced compared with s110_nrf51_8.0.0. Look at linker scripts.

s110 on SDK 10.0.0:

MEMORY
{
  FLASH (rx) : ORIGIN = 0x18000, LENGTH = 0x28000
  RAM (rwx) :  ORIGIN = 0x20002000, LENGTH = 0x6000
}

s130 on SDK 11.0.0-2.alpha:

MEMORY
{
  FLASH (rx) : ORIGIN = 0x1b000, LENGTH = 0x25000
  RAM (rwx) :  ORIGIN = 0x20001f00, LENGTH = 0x6100
}

Although flash usage grew, now we have more RAM. :)