the way of reducing softdevice resource consumption

[Gerbert Shnauer]

Hello,

in the new version of sdk (11.0.0) you support s130 only. That means the code contains both peripheral and central implementation. Does it mean that s130 consume more RAM resources than s110 and s120 separately? If so, how to reduce consumption of RAM?

[monpetit]

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. :)

[Gerbert Shnauer]

Well, these values are not for the SoftDevice.

[monpetit]

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

[Gerbert Shnauer]

$ 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

[monpetit]

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
...

[Hung Bui]

@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.