[G0] Workaround for mass storage upload

Current ST-Link firmware limits the RAM size to 32k while 36k is
available if parity check is disabled.
This could be revert when ST-Link firmware properly handle this.

Signed-off-by: Frederic.Pillon <[email protected]>

Author: fpistm

boards.txt

@@ -246,7 +246,7 @@ Nucleo_64.menu.pnum.NUCLEO_F446RE.build.cmsis_lib_gcc=arm_cortexM4l_math
 Nucleo_64.menu.pnum.NUCLEO_G071RB=Nucleo G071RB
 Nucleo_64.menu.pnum.NUCLEO_G071RB.node=NODE_G071RB
 Nucleo_64.menu.pnum.NUCLEO_G071RB.upload.maximum_size=131072
-Nucleo_64.menu.pnum.NUCLEO_G071RB.upload.maximum_data_size=36864
+Nucleo_64.menu.pnum.NUCLEO_G071RB.upload.maximum_data_size=32768
 Nucleo_64.menu.pnum.NUCLEO_G071RB.build.mcu=cortex-m0plus
 Nucleo_64.menu.pnum.NUCLEO_G071RB.build.board=NUCLEO_G071RB
 Nucleo_64.menu.pnum.NUCLEO_G071RB.build.series=STM32G0xx

variants/NUCLEO_G071RB/ldscript.ld

@@ -32,15 +32,15 @@
 ENTRY(Reset_Handler)
 
 /* Highest address of the user mode stack */
-_estack = 0x20009000;    /* end of RAM */
+_estack = 0x20008000;    /* end of RAM */
 /* Generate a link error if heap and stack don't fit into RAM */
 _Min_Heap_Size = 0x200;      /* required amount of heap  */
 _Min_Stack_Size = 0x400; /* required amount of stack */
 
 /* Specify the memory areas */
 MEMORY
 {
-RAM (xrw)      : ORIGIN = 0x20000000, LENGTH = 36K
+RAM (xrw)      : ORIGIN = 0x20000000, LENGTH = 32K
 FLASH (rx)      : ORIGIN = 0x8000000, LENGTH = 128K
 }