diff mbox series

[PATCHv3,3/3] net/lwip: add doc/develop/net_lwip.rst

Message ID 20230705151421.10792-4-maxim.uvarov@linaro.org
State Superseded
Headers show
Series net/lwip: add lwip library for the network stack | expand

Commit Message

Maxim Uvarov July 5, 2023, 3:14 p.m. UTC 
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

Comments

Simon Glass July 6, 2023, 3:57 p.m. UTC | #1 
Hi Maxim,

On Wed, 5 Jul 2023 at 09:17, Maxim Uvarov <maxim.uvarov@linaro.org> 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..2520fe11b1
> --- /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

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.
> --
> 2.30.2
>

Regards,
SImon
diff mbox series

Patch

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..2520fe11b1
--- /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.