diff options
Diffstat (limited to 'nuttx/configs/nutiny-nuc120/README.txt')
| -rw-r--r-- | nuttx/configs/nutiny-nuc120/README.txt | 57 |
1 files changed, 29 insertions, 28 deletions
diff --git a/nuttx/configs/nutiny-nuc120/README.txt b/nuttx/configs/nutiny-nuc120/README.txt index c2359b0cd..91bfc22fb 100644 --- a/nuttx/configs/nutiny-nuc120/README.txt +++ b/nuttx/configs/nutiny-nuc120/README.txt @@ -349,34 +349,35 @@ Where <subdir> is one of the following: of an RS-232 serial console. However, that configuration has not been impelmented as of this writing. - 4. This configuration includes USB Support (CDC/ACM device) + 4. Memory Usage. The size command gives us the static memory usage. + This is what I get: - CONFIG_STM32_USB=y : STM32 USB device support - CONFIG_USBDEV=y : USB device support must be enabled - CONFIG_CDCACM=y : The CDC/ACM driver must be built - CONFIG_NSH_BUILTIN_APPS=y : NSH built-in application support must be enabled - CONFIG_NSH_ARCHINIT=y : To perform USB initialization + $ size nuttx + text data bss dec hex filename + 35037 106 1092 36235 8d8b nuttx - The CDC/ACM example is included as two NSH "built-in" commands. - - CONFIG_EXAMPLES_CDCACM=y : Enable apps/examples/cdcacm - - The two commands are: - - sercon : Connect the serial device a create /dev/ttyACM0 - serdis : Disconnect the serial device. - - NOTE: The serial connections/disconnections do not work as advertised. - This is because the NuTiny-SDK-NUC120 board does not provide circuitry for - control of the "soft connect" USB pullup. As a result, the host PC - does not know the USB has been logically connected or disconnected. You - have to follow these steps to use USB: - - 1) Start NSH with USB disconnected - 2) enter to 'sercon' command to start the CDC/ACM device, then - 3) Connect the USB device to the host. - - and to close the connection: + And we can get the runtime memory usage from the NSH free command: + + NuttShell (NSH) NuttX-6.25 + nsh> free + total used free largest + Mem: 14160 3944 10216 10216 + nsh> + + Summary: + + - This slightly tuned NSH example uses 34.2KB of FLASH leaving 93.8KB + of FLASH (72%) free from additional application development. + + I did not do all of the arithmetic, but it appears to me that of this + 34+KB of FLASH usage, probably 20-30% of the FLASH is used by libgcc! + libgcc has gotten very fat! + + - Static SRAM usage is about 1.2KB (<4%). + + - At run time, 10.0KB of SRAM (62%) is still available for additional + applications. Most of the memory used at runtime is allocated I/O + buffers and the stack for the NSH main thread (1.5KB). - 4) Disconnect the USB device from the host - 5) Enter the 'serdis' command + There is probably enough free memroy to support 3 or 4 application + threads in addition to NSH. |