add demo code for STM32L433xC

Closes #27

Makefile

@@ -172,3 +172,9 @@ stm32f429xi_hs 32f429zi-nucleo_hs:
 						LDSCRIPT='demo/stm32f429xi.ld' \
 						DEFINES='STM32F4 STM32F429xx USBD_PRIMARY_OTGHS USBD_SOF_DISABLED' \
 						CFLAGS='-mcpu=cortex-m4 -mthumb'
+
+stm32l433cc:
+	@$(MAKE) clean demo STARTUP='$(CMSISDEV)/ST/STM32L4xx/Source/Templates/gcc/startup_stm32l433xx.s' \
+						LDSCRIPT='demo/stm32l433xc.ld' \
+						DEFINES='STM32L4 STM32L433xx USBD_SOF_DISABLED' \
+						CFLAGS='-mcpu=cortex-m4 -mthumb'

demo/cdc_startup.c

@@ -49,7 +49,7 @@ static void cdc_init_rcc (void) {
     _BMD(RCC->CFGR, RCC_CFGR_SW, RCC_CFGR_SW_PLL);
     _WVL(RCC->CFGR, RCC_CFGR_SWS, RCC_CFGR_SWS_PLL);
 
-#elif defined(STM32L4)
+#elif defined(STM32L476xx)
     _BST(RCC->APB1ENR1, RCC_APB1ENR1_PWREN);
     /* Set power Range 1 */
     _BMD(PWR->CR1, PWR_CR1_VOS, PWR_CR1_VOS_0);
@@ -167,6 +167,23 @@ static void cdc_init_rcc (void) {
     /* switch to PLL */
     _BMD(RCC->CFGR, RCC_CFGR_SW, RCC_CFGR_SW_PLL);
     _WVL(RCC->CFGR, RCC_CFGR_SWS, RCC_CFGR_SWS_PLL);
+#elif defined(STM32L433xx)
+    /* using HSI16 as AHB/CPU clock, HSI48 as USB PHY clock */
+    _BST(RCC->CR, RCC_CR_HSION);
+    _WBS(RCC->CR, RCC_CR_HSIRDY);
+    _BMD(RCC->CFGR, RCC_CFGR_SW, RCC_CFGR_SW_HSI);
+    _WVL(RCC->CFGR, RCC_CFGR_SWS, RCC_CFGR_SWS_HSI);
+    _BST(RCC->CRRCR, RCC_CRRCR_HSI48ON);
+    _WBS(RCC->CRRCR, RCC_CRRCR_HSI48RDY);
+    _BMD(RCC->CCIPR, RCC_CCIPR_CLK48SEL, 0);
+    /* setup PA11 PA12 to AF10 (USB FS) */
+    _BST(RCC->AHB2ENR, RCC_AHB2ENR_GPIOAEN);
+    _BST(GPIOA->AFR[1], (0x0A << 12) | (0x0A << 16));
+    _BMD(GPIOA->MODER, (0x03 << 22) | (0x03 << 24), (0x02 << 22) | (0x02 << 24));
+    /* Disabling USB Vddusb power isolation. Vusb connected to Vdd */
+    _BST(RCC->APB1ENR1, RCC_APB1ENR1_PWREN);
+    _BST(PWR->CR2, PWR_CR2_USV);
+
 #else
     #error Not supported
 #endif

demo/stm32l433xc.ld

@@ -0,0 +1,88 @@
+ENTRY(Reset_Handler)
+MEMORY
+{
+    ROM   (rx): ORIGIN = 0x08000000, LENGTH = 256K
+    RAM  (rwx): ORIGIN = 0x20000000, LENGTH = 48K
+    SRAM (rwx): ORIGIN = 0x10000000, LENGTH = 16K
+}
+SECTIONS
+{
+    .text :
+    {
+        KEEP(*(.isr_vector))
+        *(.text*)
+        KEEP(*(.init))  KEEP(*(.fini))
+        *crtbegin.o(.ctors)
+        *crtbegin?.o(.ctors)
+        *(EXCLUDE_FILE(*crtend?.o *crtend.o) .ctors)
+        *(SORT(.ctors.*))
+        *(.ctors)
+        *crtbegin.o(.dtors)
+        *crtbegin?.o(.dtors)
+        *(EXCLUDE_FILE(*crtend?.o *crtend.o).dtors)
+        *(SORT(.dtors.*))
+        *(.dtors)
+        *(.rodata*)
+        KEEP(*(.eh_frame*))
+    } > ROM
+    .ARM.extab :
+    {
+        *(.ARM.extab* .gnu.linkonce.armextab.*)
+    } > ROM
+    __exidx_start = .;
+    .ARM.exidx :
+    {
+        *(.ARM.exidx* .gnu.linkonce.armexidx.*)
+    } > ROM
+    __exidx_end = .;
+    __etext = .;
+    .data : AT (__etext)
+    {
+        __data_start__ = .;
+        *(vtable)
+        *(.data*)
+        . = ALIGN(4);
+        PROVIDE_HIDDEN (__preinit_array_start = .);
+        KEEP(*(.preinit_array))
+        PROVIDE_HIDDEN (__preinit_array_end = .);
+        . = ALIGN(4);
+        PROVIDE_HIDDEN (__init_array_start = .);
+        KEEP(*(SORT(.init_array.*)))
+        KEEP(*(.init_array))
+        PROVIDE_HIDDEN (__init_array_end = .);
+        . = ALIGN(4);
+        PROVIDE_HIDDEN (__fini_array_start = .);
+        KEEP(*(SORT(.fini_array.*)))
+        KEEP(*(.fini_array))
+        PROVIDE_HIDDEN (__fini_array_end = .);
+        . = ALIGN(4);
+        __data_end__ = .;
+    } > RAM
+    .bss (NOLOAD) :
+    {
+        __bss_start__ = .;
+        *(.bss*)
+        *(COMMON)
+        __bss_end__ = .;
+    } > RAM
+    .heap (NOLOAD) :
+    {
+        __end__ = .;
+        *(.heap*)
+        __HeapLimit = .;
+    } > RAM
+    .stack_dummy (NOLOAD) :
+    {
+        *(.stack)
+    } > RAM
+    __StackTop = ORIGIN(RAM) + LENGTH(RAM);
+    __StackLimit = __StackTop - SIZEOF(.stack_dummy);
+    PROVIDE(__stack = __StackTop);
+    ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
+    PROVIDE(_estack = __stack);
+    PROVIDE(_sidata = __etext);
+    PROVIDE(_sdata = __data_start__);
+    PROVIDE(_edata = __data_end__);
+    PROVIDE(_sbss = __bss_start__);
+    PROVIDE(_ebss = __bss_end__);
+}