I want to reduce the memory consumption to NuttX in the stm32f103-minimum board to get external SPI NOR Flash with SmartFS and USB Serial Console at same time.
After mount the SmartFS partition I will have only 808 bytes of RAM:
nsh> free total used free largest Mem: 17536 15352 2184 2184 nsh> mksmartfs /dev/smart0p1 nsh> free total used free largest Mem: 17536 15352 2184 2184 nsh> mount -t smartfs /dev/smart0p1 /mnt nsh> free total used free largest Mem: 17536 16728 808 808 nsh>
Analyzing which features are consumpting more RAM I notice the interruption vector table is the using more than 600 bytes:
$ arm-none-eabi-nm --print-size --size-sort --radix dec -C nuttx | grep ' [DdBb] ' | tail -20 536873088 00000008 B g_sigpendingirqaction 536873096 00000008 B g_sigpendingirqsignal 536873104 00000008 B g_sigpendingsignal 536872252 00000008 B g_waitingforsemaphore 536872280 00000008 B g_waitingforsignal 536873124 00000008 B g_wdactivelist 536873112 00000008 B g_wdfreelist 536872436 00000016 B g_hpwork 536873296 00000028 B g_spawn_parms 536871024 00000028 d g_spi1dev 536871860 00000028 b g_syslog_dev 536870912 00000092 d g_usart1priv 536871764 00000096 b g_wdpool 536872288 00000128 B g_pidhash 536873132 00000164 B g_mmheap 536871564 00000188 b g_idletcb 536871308 00000256 b g_usart1rxbuffer 536871052 00000256 b g_usart1txbuffer 536871888 00000328 b g_usbdev 536872452 00000608 B g_irqvector
Fortunately there is an option to reduce it:
http://www.nuttx.org/doku.php?id=wiki:howtos:smallvectors
Keep tuned!
