自从上次莫名其妙的解决了u-boot-1.3.0&eldk malloc 问题后，终于能够正常进入U-BOOT命令行界面.

首先试一下ping 命令，因为总不至于用kermit/JTAG把程序down来down去吧，网络才是王道,结果：（

u-boot-1.3.0 => run ping
sending ICMP for 0102a8c0
ARP broadcast 1
eth_send() start...
eth_rx() start...
chip id = 0x50,0x70
eth_rx(): rtl8019 packet received with no error
eth_rx()->nic_to_pc()

nic_to_pc() start ...
next_packet_pointer=2
nf: NetReceive() packet received
Receive from protocol 0x806
Got ARP
Got ARP REPLY, set server/gtwy eth addr (00:1c:23:86:48:2f)
Got it
ARP broadcast 1
eth_send() start...
nic_to_pc() current_point = 2  //rtl8019内部ram地址明明是0x40~0x80,怎么可能是2,晃点我老人家呀～～～～
eth_rx()->boundary=2 //
eth_rx(): rtl8019 packet received with no error
eth_rx()->nic_to_pc()

nic_to_pc() start ...
next_packet_pointer=2
packet too big! <rxlen = 65532 bytes>   //!!!!!!!!!!!

这个问题整整花了两周时间，今天终于搞定了，哇哈哈哈哈哈哈

我的U-BOOT 是从1.1升级过来的，按理说1.1.1上面能够正常运行的移植到1.3版本之后不会发生什么大的问题的。

去网上搜索了一下，不少N人说是硬件时序问题。可是老版本明明正常工作的呀。（备注：关于RTL8019 寄存器baseaddress

问题，如果开发板上只接了5根地址线，那么base address仅仅跟gcs引脚相关， 与rtl8019的0x200,0x300没有任何关系随便

0x06000000还是0x06000100，0x06000200，0x06000300都能正常工作）

就在我试了各种方法，什么电路，代码，datasheet，sniffer...毫无办法准备放弃之时终于找到了“救星”

http://blackfin.uclinux.org/gf/project/toolchain/tracker/?action=TrackerItemEdit&tracker_item_id=719

摘要如下：

Problem:
bfin-elf-gcc compiler generates wrong code with optimization {-Os} (By default
Makefile has optimization for size). (Disabling the optimization solves the
problem)

Code snippet: File -drivers/rtl8019.c Function -nic_to_pc()
rec_head_status = get_reg (RTL8019_DMA_DATA);
next_packet_pointer = get_reg (RTL8019_DMA_DATA);
packet_length0 = get_reg (RTL8019_DMA_DATA);
packet_length1 = get_reg (RTL8019_DMA_DATA);

Instead of generating asm instruction four times for get_reg function. The
toolchain optimizes & generates code for a single get_reg . This is wrong
and will cause wrong packet size.

Regards,
Manigandan

reply：

In the driver, RTL8019_DMA_DATA may be the MMR. Each read will return a new
value. But gcc don't know of this information if you don't tell it.

By defining get_reg() as following, you may get what you want:

static unsigned char get_reg (unsigned int regno)
{
return (*(volatile unsigned char *) regno);
}

原来都是因为少了它---->!!!!!!volatile!!!!!!!

加上一切搞定：）

u-boot-1.3.0 => run ping
sending ICMP for 0102a8c0
ARP broadcast 1
eth_send() start...
eth_rx() start...
chip id = 0x50,0x70
eth_rx(): rtl8019 packet received with no error
eth_rx()->nic_to_pc()

nic_to_pc() start ...
next_packet_pointer=77
nf: NetReceive() packet received
Receive from protocol 0x806
Got ARP
Got ARP REPLY, set server/gtwy eth addr (00:1c:23:86:48:2f)
Got it
eth_send() start...
nic_to_pc() current_point = 77    //这才乖^_^
eth_rx()->boundary=77
eth_rx(): rtl8019 packet received with no error
eth_rx()->nic_to_pc()

nic_to_pc() start ...
next_packet_pointer=78
nf: NetReceive() packet received
Receive from protocol 0x800
Got IP
len=28, v=45
PingHandler() start...
PingHandler() return NETLOOP_SUCCESS
nic_to_pc() current_point = 78
eth_rx()->boundary=78
host 192.168.2.1 is alive

说来也奇怪，在1.3.0的代码中明明已经有人把put_reg中的volatile加上了，干嘛不一起把get_reg中的volatile

也加上，搞得我们这些后辈人人郁闷之至...（我在网上看到了很多跟我一样郁闷的人，敬意此帖奉上）