Stub for stm32h7 built-in bootloader

Author: andoma

src/platform/stm32h7/boot/isr.S

@@ -0,0 +1,22 @@
+        .syntax unified
+        .text
+        .thumb
+        .section    .bootloader_vector,"a",%progbits
+        .align      2
+        .global     bootloader_vectors
+        .type   bootloader_vectors, %object
+
+
+
+bootloader_vectors:
+        .long _sdata          // Main stack (MSP) start before data-section
+        .long bl_start
+        .long bl_nmi
+        .long bl_hard_fault
+
+        .long bl_mm_fault
+        .long bl_bus_fault
+        .long bl_usage_fault
+
+        .size bootloader_vectors, . - bootloader_vectors
+

src/platform/stm32h7/boot/stm32h7_bootloader.c

@@ -0,0 +1,40 @@
+#include <stdint.h>
+
+extern uint32_t vectors[];
+
+void __attribute__((section("bltext"),noinline,noreturn)) bl_start(void)
+{
+  void (*init)(void) __attribute__((noreturn))  = (void *)vectors[1];
+  init();
+}
+
+void __attribute__((section("bltext"),noinline))
+bl_nmi(void)
+{
+  while(1) {}
+}
+
+void __attribute__((section("bltext"),noinline))
+bl_hard_fault(void)
+{
+  while(1) {}
+}
+
+void __attribute__((section("bltext"),noinline))
+bl_mm_fault(void)
+{
+  while(1) {}
+}
+
+void __attribute__((section("bltext"),noinline))
+bl_bus_fault(void)
+{
+  while(1) {}
+}
+
+void __attribute__((section("bltext"),noinline))
+bl_usage_fault(void)
+{
+  while(1) {}
+}
+

src/platform/stm32h7/stm32h7.mk

@@ -4,7 +4,9 @@ GLOBALDEPS += ${P}/stm32h7.mk
 
 CPPFLAGS += -iquote${P} -include ${P}/stm32h7.h
 
-LDSCRIPT = ${P}/stm32h7.ld
+LDSCRIPT ?= ${P}/stm32h7$(if $(subst no,,${ENABLE_BUILTIN_BOOTLOADER}),_bootloader,).ld
+
+ENTRYPOINT ?= $(if $(subst no,,${ENABLE_BUILTIN_BOOTLOADER}),bl_start,start)
 
 include ${SRC}/cpu/cortexm/cortexm7.mk
 
@@ -31,3 +33,8 @@ SRCS-${ENABLE_NET_IPV4} += \
 
 ${MOS}/platform/stm32h7/%.o : CFLAGS += ${NOFPU}
 
+SRCS-${ENABLE_BUILTIN_BOOTLOADER} += \
+	${P}/boot/stm32h7_bootloader.c \
+	${P}/boot/isr.s \
+
+${MOS}/platform/stm32h7/boot/stm32h7_bootloader.o : CFLAGS = -Os -ffreestanding -Wall -Werror -mcpu=cortex-m7 -mthumb -mfloat-abi=hard -mfpu=fpv5-d16 -mgeneral-regs-only -include ${BOOTLOADER_DEFS}

src/platform/stm32h7/stm32h7_bootloader.ld

@@ -0,0 +1,20 @@
+MEMORY {
+         BOOT  (rx) : ORIGIN = 0x08000000, LENGTH = 128K
+         VTBL  (rx) : ORIGIN = 0x08020000, LENGTH = 1K
+         FLASH (rx) : ORIGIN = 0x08020400, LENGTH = 383K
+         RAM   (xrw): ORIGIN = 0x20000400, LENGTH = 128K
+}
+
+NOCROSSREFS(.boot .text)
+
+SECTIONS {
+        .boot : {
+                . = ALIGN(4);
+                KEEP(*(.bootloader_vector))
+                *(bltext)
+                *(bldata)
+                . = ALIGN(4);
+        } >BOOT
+}
+
+INCLUDE cpu/cortexm/cortexm.ld