From 64bb06f292c5d5def968616d3f79cf99cc76646d Mon Sep 17 00:00:00 2001
From: kuwoyuki <kuwoyuki@cock.li>
Date: Fri, 12 Dec 2025 23:05:27 +0600
Subject: [PATCH] fix: idk

---
 ch32fun           |  2 +-
 inc/hw_i2c.h      |  9 +++++----
 port/ethernetif.c | 36 ++++++++++++++++--------------------
 port/lwipopts.h   |  2 +-
 4 files changed, 23 insertions(+), 26 deletions(-)

diff --git a/ch32fun b/ch32fun
index d38b104..b076400 160000
--- a/ch32fun
+++ b/ch32fun
@@ -1 +1 @@
-Subproject commit d38b104838595e0203eed5a6067e83fe7fc56c8c
+Subproject commit b0764004f578628ba40f5066cbe924eb57f58f90
diff --git a/inc/hw_i2c.h b/inc/hw_i2c.h
index 6b2f5b9..659d3d1 100644
--- a/inc/hw_i2c.h
+++ b/inc/hw_i2c.h
@@ -150,10 +150,11 @@ static inline void i2c_init(void) {
   RCC->APB2PCENR |= RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO;
   RCC->APB1PCENR |= RCC_APB1Periph_I2C1;
 
-  // PB6 (SCL) and PB7 (SDA)
-  GPIOB->CFGLR &= ~(0xFF << (4 * 6));
-  GPIOB->CFGLR |= ((GPIO_Speed_10MHz | GPIO_CNF_OUT_OD_AF) << (4 * 6)) |
-                  ((GPIO_Speed_10MHz | GPIO_CNF_OUT_OD_AF) << (4 * 7));
+  AFIO->PCFR1 |= AFIO_PCFR1_I2C1_REMAP;  // I2C1_RM: 1
+
+  // PB8 (SCL) and PB9 (SDA)
+  funPinMode(PB8, GPIO_CFGLR_OUT_10Mhz_AF_OD);
+  funPinMode(PB9, GPIO_CFGLR_OUT_10Mhz_AF_OD);
 
   // Reset I2C1 to init all regs
   RCC->APB1PRSTR |= RCC_APB1Periph_I2C1;
diff --git a/port/ethernetif.c b/port/ethernetif.c
index 20e68c4..0dcc44e 100644
--- a/port/ethernetif.c
+++ b/port/ethernetif.c
@@ -70,6 +70,15 @@ err_t ethernetif_init(struct netif* netif) {
 static err_t low_level_output(struct netif* netif, struct pbuf* p) {
   (void)netif;
 
+  // single-segment pbuf
+  if (p->next == NULL && p->len <= ETH_TX_BUF_SIZE) {
+    if (eth_send_packet(p->payload, p->len) == 0) {
+      LINK_STATS_INC(link.xmit);
+      return ERR_OK;
+    }
+  }
+
+  // chain of pbufs
   static uint8_t tx_buffer[ETH_TX_BUF_SIZE];
   uint32_t total_len = 0;
 
@@ -82,21 +91,13 @@ static err_t low_level_output(struct netif* netif, struct pbuf* p) {
     total_len += q->len;
   }
 
-  // send packet via driver
-  int result = eth_send_packet(tx_buffer, total_len);
-
-  if (result == -1) {
-    // tx queue full
-    LINK_STATS_INC(link.drop);
-    return ERR_BUF;
-  } else if (result == -2) {
-    // invalid length
-    LINK_STATS_INC(link.err);
-    return ERR_ARG;
+  if (eth_send_packet(tx_buffer, total_len) == 0) {
+    LINK_STATS_INC(link.xmit);
+    return ERR_OK;
   }
 
-  LINK_STATS_INC(link.xmit);
-  return ERR_OK;
+  LINK_STATS_INC(link.drop);
+  return ERR_BUF;
 }
 
 void ethernetif_input(struct netif* netif) {
@@ -108,13 +109,8 @@ void ethernetif_input(struct netif* netif) {
     struct pbuf* p = pbuf_alloc(PBUF_RAW, length, PBUF_POOL);
 
     if (p != NULL) {
-      // copy packet into pbuf chain
-      uint32_t offset = 0;
-      for (struct pbuf* q = p; q != NULL; q = q->next) {
-        memcpy(q->payload, packet + offset, q->len);
-        offset += q->len;
-      }
-
+      // usually contiguous in PBUF_POOL
+      pbuf_take(p, packet, length);
       LINK_STATS_INC(link.recv);
 
       // pass to lwIP
diff --git a/port/lwipopts.h b/port/lwipopts.h
index 7a57d25..26188cf 100644
--- a/port/lwipopts.h
+++ b/port/lwipopts.h
@@ -11,7 +11,7 @@
 // #define ETHARP_DEBUG LWIP_DBG_ON
 
 #define NO_SYS 1
-#define SYS_LIGHTWEIGHT_PROT 1
+#define SYS_LIGHTWEIGHT_PROT 0
 #define LWIP_NETCONN 0
 #define LWIP_SOCKET 0