Commonise flash-based OTA. Add h7 support.

src/util.h

@@ -32,6 +32,21 @@ uint64_t mg_now(void);     // Return milliseconds since Epoch
 #define MG_IPADDR_PARTS(ADDR) \
   MG_U8P(ADDR)[0], MG_U8P(ADDR)[1], MG_U8P(ADDR)[2], MG_U8P(ADDR)[3]
 
+#define MG_REG(x) ((volatile uint32_t *) (x))[0]
+#define MG_BIT(x) (((uint32_t) 1U) << (x))
+#define MG_SET_BITS(R, CLRMASK, SETMASK) (R) = ((R) & ~(CLRMASK)) | (SETMASK)
+
+#define MG_ROUND_UP(x, a) ((a) == 0 ? (x) : ((((x) + (a) -1) / (a)) * (a)))
+#define MG_ROUND_DOWN(x, a) ((a) == 0 ? (x) : (((x) / (a)) * (a)))
+
+#ifdef __GNUC__
+#define MG_ARM_DISABLE_IRQ() asm volatile ("cpsid i" : : : "memory")
+#define MG_ARM_ENABLE_IRQ() asm volatile ("cpsie i" : : : "memory")
+#else
+#define MG_ARM_DISABLE_IRQ()
+#define MG_ARM_ENABLE_IRQ()
+#endif
+
 struct mg_addr;
 int mg_check_ip_acl(struct mg_str acl, struct mg_addr *remote_ip);