Josh & Frank, Sorry again for dropping the ball on this one. This is a useful feature that we should add to U-boot, but I'm concerned about the memory footprint.
Josh Boyer wrote: > From: Frank Haverkamp <[EMAIL PROTECTED]> > > http://tools.ietf.org/html/rfc2348 describes the TFTP block size option > which allows larger packtes than the 512 byte default. This reduces the > number of TFTP ACKs significantly and improves performance. > > To get the most benefit out of the tftp block size option the support > of defragementation of IP/UDP packet is helpful. The current implemenation > should work even with packets received out of order. To enable the large > packet size the user should set "tftp_block_size" so a value like 16352. > > We experimented with different packet sizes and found that more than those > 16KiB do not contribute much to the performance anymore. Therefor I limited > the defragmentation buffer to 16KiB no too waste memory. > > Signed-off-by: Frank Haverkamp <[EMAIL PROTECTED]> > Signed-off-by: Josh Boyer <[EMAIL PROTECTED]> > > > --- > include/net.h | 17 ++++++ > net/net.c | 156 > ++++++++++++++++++++++++++++++++++++++++++++++++++-------- > net/tftp.c | 22 ++++++++ > net/tftp.h | 10 +++ > 4 files changed, 185 insertions(+), 20 deletions(-) > > --- u-boot.git.orig/include/net.h > +++ u-boot.git/include/net.h > @@ -200,6 +200,13 @@ typedef struct { > ushort udp_xsum; /* Checksum */ > } IP_t; > > +#define IP_OFFS 0x1FFF /* ip offset *= 8 */ > +#define IP_OFFS_SHIFT 3 /* in 8 byte steps */ > +#define IP_FLAGS 0xE000 /* first 3 bits */ > +#define IP_FLAGS_RES 0x8000 /* reserved */ > +#define IP_FLAGS_DFRAG 0x4000 /* don't fragments */ > +#define IP_FLAGS_MFRAG 0x2000 /* more fragments */ > + > #define IP_HDR_SIZE_NO_UDP (sizeof (IP_t) - 8) > #define IP_HDR_SIZE (sizeof (IP_t)) > > @@ -282,6 +289,16 @@ typedef struct icmphdr { > #define PKTSIZE_ALIGN 1536 > /*#define PKTSIZE 608*/ > > + /* > + * IP/UDP Fragmentation support > + * See: http://en.wikipedia.org/wiki/IPv4#Fragmentation_and_reassembly > + * MAX possible UDP packet size is 64 KiB, if there is memory available. > + */ > +#define NET_ETH_MTU 1500 > +#define NET_FRAG_BUF_SIZE (16 * 1024) /* MAX is 64 KiB */ > +#define NET_UDP_FRAG_SIZE (NET_ETH_MTU - IP_HDR_SIZE_NO_UDP) /* 1480 */ > +#define NET_FRAG_BUF_USED (NET_FRAG_BUF_SIZE / NET_UDP_FRAG_SIZE + 1) > + > /* > * Maximum receive ring size; that is, the number of packets > * we can buffer before overflow happens. Basically, this just > --- u-boot.git.orig/net/net.c > +++ u-boot.git/net/net.c > @@ -192,6 +192,15 @@ volatile uchar PktBuf[(PKTBUFSRX+1) * PK > > volatile uchar *NetRxPackets[PKTBUFSRX]; /* Receive packets > */ > > +/* Packet fragmentation support */ > +static uint16_t ip_id = 0; /* sequence number */ > +static uint16_t udp_len = 0; > +static uint16_t udp_src = 0; > +static uint16_t udp_dst = 0; > +static int max_idx = 0; > +static uchar NetFragBuf[NET_FRAG_BUF_SIZE]; > Allocating a 16k buffer should be optional. Please consider wrapping this feature in a CONFIG. > +static char NetFragBufUsed[NET_FRAG_BUF_USED] = { 0, }; > + > static rxhand_f *packetHandler; /* Current RX packet handler > */ > static thand_f *timeHandler; /* Current timeout handler > */ > static ulong timeStart; /* Time base value > */ > @@ -288,6 +297,13 @@ NetLoop(proto_t protocol) > { > bd_t *bd = gd->bd; > > + /* Packet fragmentation support */ > + ip_id = udp_len = udp_src = udp_dst = max_idx = 0; > + memset(NetFragBuf, 0xFF, sizeof(NetFragBuf)); > + memset(NetFragBufUsed, 0, sizeof(NetFragBufUsed)); > + printf("NetFragBuf @ %08x max tftp_block_size=%d udp_frag_size=%d\n", > + NetFragBuf, TFTP_BLOCK_SIZE_MAX, NET_UDP_FRAG_SIZE); > I get a compiler warning here that a simple cast should fix: net.c: In function 'NetLoop': net.c:300: warning: format '%08x' expects type 'unsigned int', but argument 2 has type 'uchar *' regards, Ben _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
