Have you turned off Debug?
Is GCC compiler optimization options set for Speed or Size?
Is this a Bootloadable project or Normal project?
All above changes SRAM (and FLASH) usage. Just some suggestions to look at.
Open the .map file and scroll down (or search) for 0x20000000. This is the start of .ramvectors. By adding up all the used bytes, you should reach 1616 SRAM byte used.
When I compiled an empty project, using same processor, Creator 3.1, this is what it generated (I've deleted some lines to shorten the text):
Flash used: 776 of 32768 bytes (2.4 %).
SRAM used: 1404 of 4096 bytes (34.3 %). Stack: 1024 bytes. Heap: 128 bytes.
.ramvectors 0x20000000 0xc0
0x20000000 __cy_region_start_ram = .
.noinit 0x200000c0 0x4
.noinit 0x200000c0 0x4 .\CortexM0\ARM_GCC_484\Release\Cm0Start.o
.data 0x200000c8 0x18 load address 0x000002f0
0x200000c8 __cy_region_start_data = .
.jcr 0x200000c8 0x4 c:/program files/cypress/psoc creator/3.1/psoc creator/import/gnu_cs/arm/4.8.4/bin/../lib/gcc/arm-none-eabi/4.8.4/armv6-m/crtend.o
*(.data .data.* .gnu.linkonce.d.*)
.data 0x200000cc 0x10 .\CortexM0\ARM_GCC_484\Release\Design02.a(CyLib.o)
0x200000e0 . = ALIGN (0x8)
*fill* 0x200000dc 0x4
.bss 0x200000e0 0x20 load address 0x00000308
0x20000100 . = ALIGN (0x8)
.heap 0x20000100 0x80 load address 0x00000308
0x20000180 . = (. + 0x80)
.stack 0x20000c00 0x400
0x20000c00 __cy_stack_limit = .
0x20001000 . = (. + 0x400)
When I add up SRAM used, it does equal 1404 (in my example build).
For the most part, it's the Stack and Heap, that takes up most SRAM.
The rest is taken up with other variables for Vectors,Timers, fill bytes,2 sets of Load Addresses,
1152+252=1404 as reported by Creator.
Maybe I could reduce SRAM usage if I also disabled the library options.
I changed the linker build settings similar to yours and I had the same result as you did.
I then set each of the libraries back to True (one-by-one) and found the Use newlib-nano = False is the culprit. If you set this back to TRUE, less SRAM is used and the .data.impure_data will dissappear.
This appears to be a bug.
I hope somebody from Cypress will comment.
To utilize Cypress provided initialize and startup function it is better using
the default settings.
And I think that the initial SRAM usage is more depending on the stack and heap size.
So in the Workspace Explorer > Project > Design Wide Resources > System
I tried to change
Heap Size 0x80 > 0x10
Stack Size 0x0400 > 0x0040
Although I'm not sure if this is practical, the result SRAM usage was 464 bytes (11.3%)
As the output said Stack 64 bytes Heap 16 bytes, rest of 384 byte must have been reserved for the library.
And IMHO, 384 does not seem to be very big for a 32 bit CPU.