1 - The current linker flags undefines `Reset_Handler' and uses `entry()' as
default entry point (specified by `-e'), which will cause a invalid reset
vector in the image without proper crt0 init assembly routine.
2 - The default startup files provided by NXP violate the crt0 assumption
that bss section will be filled with zero unless macro `__STARTUP_CLEAR_BSS'
is defined. This will cause RTT hook funtion pointers set to non-NULL values at
kernel start, thus successfully passes the `RT_nnnn_HOOK_CALL` checks
and jumps to an invalid pointer.
3 - The default heap size used by TCB and kernel objects are set by
linker file macros, which is 0x400 (1024 bytes). The size is too small
for main task and the allocation will fail before the first task being created.
This patch restores Reset_Handler as default reset vector and executes
entry by replacing __START from newlib, defines the
`__STARTUP_CLEAR_BSS` macro to forcibly zeroize the bss section to avoid
unexpected hard faults, set proper heap sizes based on the SRAM sizes.
Some unused compiler/linker flags are also removed or replaced to avoid
future confusion.
The heap sizes for different devices are:
* LPC55(S)69/LPC55(S)28: 64kB
* LPC55(S)06/LPC55(S)16/LPC55(S)36: 32kB
Signed-off-by: Yilin Sun <imi415@imi.moe>
