tweak lwipopts.h

port/arch/cc.h

@@ -32,4 +32,6 @@
 
 #define LWIP_RAND() ((u32_t)rand())
 
+#include "arch/sys_arch.h"
+
 #endif /* LWIP_ARCH_CC_H */

port/arch/sys_arch.c

@@ -0,0 +1,26 @@
+#include "sys_arch.h"
+
+#include "ch32fun.h"
+#include "lwip/sys.h"
+#include "systick.h"
+
+static unsigned long next = 1;
+
+int rand(void) {
+  next = next * 1103515245 + 12345;
+  return (unsigned int)(next / 65536) % 32768;
+}
+
+void srand(unsigned int seed) { next = seed; }
+
+uint32_t sys_now(void) { return millis(); }
+
+sys_prot_t sys_arch_protect(void) {
+  __disable_irq();
+  return 1;
+}
+
+void sys_arch_unprotect(sys_prot_t pval) {
+  (void)pval;
+  __enable_irq();
+}

port/arch/sys_arch.h

@@ -0,0 +1,8 @@
+#ifndef LWIP_ARCH_SYS_ARCH_H
+#define LWIP_ARCH_SYS_ARCH_H
+
+#include <stdint.h>
+
+typedef uint32_t sys_prot_t;
+
+#endif /* LWIP_ARCH_SYS_ARCH_H */