| Message ID | 20230714142000.5534-4-maxim.uvarov@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | net/lwip: add lwip library for the network stack | expand |
Hi Maxim, On Fri, Jul 14, 2023 at 08:19:58PM +0600, Maxim Uvarov wrote: > Just add inital doc. > > Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org> > --- > doc/develop/index.rst | 1 + > doc/develop/net_lwip.rst | 59 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 60 insertions(+) > create mode 100644 doc/develop/net_lwip.rst > > diff --git a/doc/develop/index.rst b/doc/develop/index.rst > index 97c526e997..a092c33df0 100644 > --- a/doc/develop/index.rst > +++ b/doc/develop/index.rst > @@ -43,6 +43,7 @@ Implementation > smbios > spl > uefi/index > + net_lwip > vbe > version > > diff --git a/doc/develop/net_lwip.rst b/doc/develop/net_lwip.rst > new file mode 100644 > index 0000000000..567234fff2 > --- /dev/null > +++ b/doc/develop/net_lwip.rst > @@ -0,0 +1,59 @@ > +.. SPDX-License-Identifier: GPL-2.0+ > + > +LWIP IP stack intergation for U-Boot > +==================================== > + > +Intro > +----- > + > +LWIP is a library for implementation network protocols, which is commonly used s/for implementation/implementing/ > +on embedded devices. > + > +https://savannah.nongnu.org/projects/lwip/ > + > +LwIP license: > +LwIP is licensed under a BSD-style license: http://lwip.wikia.com/wiki/License. > + > +Main features include: > + > +* Protocols: IP, IPv6, ICMP, ND, MLD, UDP, TCP, IGMP, ARP, PPPoS, PPPoE > + > +* DHCP client, DNS client (incl. mDNS hostname resolver), AutoIP/APIPA (Zeroconf), SNMP agent (v1, v2c, v3, private MIB support & MIB compiler) > + > +* APIs: specialized APIs for enhanced performance, optional Berkeley-alike socket API > + > +* Extended features: IP forwarding over multiple network interfaces, TCP congestion control, RTT estimation and fast recovery/fast retransmit > + > +* Addon applications: HTTP(S) server, SNTP client, SMTP(S) client, ping, NetBIOS nameserver, mDNS responder, MQTT client, TFTP server > + > +U-Boot implementation details > +----------------------------- > + > +1. In general we can build lwIP as .a library and link it against u-boot or compile it in > +the U-Boot tree in the same way as other U-Boot files. There are few reasons why I selected > +the second variant: LwIP is very customizable with defines for features, memory size, types of > +allocation, some internal types and platform specific code. And it was more easy to enable/disable s/And it was more easy/it turned out easier to/ > +debug which is also done with defines, and is needed periodically. > + > +2. lwIP has 2 APIs - raw mode and sequential (as lwIP names it, or socket API as we name it in Linux). > +For now only raw API is supported. > + > +Raw IP means that the call back function for RX path is registered and will be called when packet s/Raw IP IP means/In raw IP mode a callback function etc > +data passes the IP stack and is ready for the application. is passed to the ip stack? > + > +Example is unmodified working ping example from lwip sources which registeres the callback: > + > +.. code-block:: c > + > + ping_pcb = raw_new(IP_PROTO_ICMP); > + raw_recv(ping_pcb, ping_recv, NULL); <- ping_recv is app callback. > + raw_bind(ping_pcb, IP_ADDR_ANY) > + > +Socket API also gives nice advantages due it will be easy to port linux socket applications to u-boot. > +I.e. LwIP sockets compatible with the linux ones. But that will require RX thread running in the background. > +So that means we need some kind of scheduler, locking and threading support or find some other solution. I think you can drop this entirely and we can add it if we ever want to support sockets > + > +3. Input and output > + > +RX packet path is injected to U-Boot eth_rx() polling loop and TX patch is in eth_send() accordingly. > +So we do not touch any drivers code and just eat packets when they are ready. > -- > 2.30.2 > Thanks /Ilias
diff --git a/doc/develop/index.rst b/doc/develop/index.rst index 97c526e997..a092c33df0 100644 --- a/doc/develop/index.rst +++ b/doc/develop/index.rst @@ -43,6 +43,7 @@ Implementation smbios spl uefi/index + net_lwip vbe version diff --git a/doc/develop/net_lwip.rst b/doc/develop/net_lwip.rst new file mode 100644 index 0000000000..567234fff2 --- /dev/null +++ b/doc/develop/net_lwip.rst @@ -0,0 +1,59 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +LWIP IP stack intergation for U-Boot +==================================== + +Intro +----- + +LWIP is a library for implementation network protocols, which is commonly used +on embedded devices. + +https://savannah.nongnu.org/projects/lwip/ + +LwIP license: +LwIP is licensed under a BSD-style license: http://lwip.wikia.com/wiki/License. + +Main features include: + +* Protocols: IP, IPv6, ICMP, ND, MLD, UDP, TCP, IGMP, ARP, PPPoS, PPPoE + +* DHCP client, DNS client (incl. mDNS hostname resolver), AutoIP/APIPA (Zeroconf), SNMP agent (v1, v2c, v3, private MIB support & MIB compiler) + +* APIs: specialized APIs for enhanced performance, optional Berkeley-alike socket API + +* Extended features: IP forwarding over multiple network interfaces, TCP congestion control, RTT estimation and fast recovery/fast retransmit + +* Addon applications: HTTP(S) server, SNTP client, SMTP(S) client, ping, NetBIOS nameserver, mDNS responder, MQTT client, TFTP server + +U-Boot implementation details +----------------------------- + +1. In general we can build lwIP as .a library and link it against u-boot or compile it in +the U-Boot tree in the same way as other U-Boot files. There are few reasons why I selected +the second variant: LwIP is very customizable with defines for features, memory size, types of +allocation, some internal types and platform specific code. And it was more easy to enable/disable +debug which is also done with defines, and is needed periodically. + +2. lwIP has 2 APIs - raw mode and sequential (as lwIP names it, or socket API as we name it in Linux). +For now only raw API is supported. + +Raw IP means that the call back function for RX path is registered and will be called when packet +data passes the IP stack and is ready for the application. + +Example is unmodified working ping example from lwip sources which registeres the callback: + +.. code-block:: c + + ping_pcb = raw_new(IP_PROTO_ICMP); + raw_recv(ping_pcb, ping_recv, NULL); <- ping_recv is app callback. + raw_bind(ping_pcb, IP_ADDR_ANY) + +Socket API also gives nice advantages due it will be easy to port linux socket applications to u-boot. +I.e. LwIP sockets compatible with the linux ones. But that will require RX thread running in the background. +So that means we need some kind of scheduler, locking and threading support or find some other solution. + +3. Input and output + +RX packet path is injected to U-Boot eth_rx() polling loop and TX patch is in eth_send() accordingly. +So we do not touch any drivers code and just eat packets when they are ready.
Just add inital doc. Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org> --- doc/develop/index.rst | 1 + doc/develop/net_lwip.rst | 59 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+) create mode 100644 doc/develop/net_lwip.rst