Hi James,
On 27/06/2026 01:27, James Hilliard wrote:
> The legacy network stack supports tftpsrv, which listens for an
> incoming TFTP write request and receives the first file into memory.
> Despite the old command help wording, the command returns after
> receiving the file and does not boot it automatically.
>
> The lwIP stack already builds the lwIP TFTP application, but only wires
> it up for client-side tftpboot. Add a lwIP tftpsrv command and
> implement the server path with tftp_init_server(). Reuse the existing
> lwIP TFTP write callback and memory copy path so LMB checks, progress
> output, filesize/fileaddr updates and EFI bootdev handling stay
> consistent with tftpboot.
>
> Track receive timeout and write-failure state around the lwIP callbacks
> so a stalled or rejected receive is not reported as a successful close.
>
> Move CMD_TFTPSRV out of the legacy-only Kconfig block so it can be
> enabled with either network stack. Update the command help text and add
> usage documentation for the receive-only behavior.
>
> Add pytest coverage for tftpsrv using a generated host file and curl's
> TFTP upload support. Enable the command in qemu_arm64_lwip_defconfig so
> the test can be run with the existing lwIP QEMU build when the boardenv
> provides env__net_tftpsrv_file.
>
> Signed-off-by: James Hilliard <[email protected]>
> ---
> Changes v1 -> v2:
> - Add tftpsrv usage documentation (suggested by Quentin Schulz)
> - Add tftpsrv pytest coverage (suggested by Quentin Schulz)
> - Enable CMD_TFTPSRV in qemu_arm64_lwip_defconfig
> - Allow tftpsrv pytest coverage to use an explicit upload URL
> - Keep tftpsrv pytest coverage gated by env__net_tftpsrv_file
> - Clarify that tftpsrv returns after receiving instead of booting
> - Update legacy and lwIP command help text for receive-only behavior
> ---
> cmd/Kconfig | 14 ++-
> cmd/lwip/Makefile | 1 +
> cmd/lwip/tftpsrv.c | 11 ++
> cmd/net.c | 4 +-
> configs/qemu_arm64_lwip_defconfig | 1 +
> doc/usage/cmd/tftpsrv.rst | 73 ++++++++++++
> include/net-lwip.h | 1 +
> net/lwip/tftp.c | 181 +++++++++++++++++++++++++++++-
> test/py/tests/test_net.py | 94 ++++++++++++++++
> 9 files changed, 367 insertions(+), 13 deletions(-)
> create mode 100644 cmd/lwip/tftpsrv.c
> create mode 100644 doc/usage/cmd/tftpsrv.rst
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index c71c6824a19..303acf8aa31 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -2127,12 +2127,6 @@ config CMD_TFTPPUT
> help
> TFTP put command, for uploading files to a server
>
> -config CMD_TFTPSRV
> - bool "tftpsrv"
> - depends on CMD_TFTPBOOT
> - help
> - Act as a TFTP server and boot the first received file
> -
> config NET_TFTP_VARS
> bool "Control TFTP timeout and count through environment"
> depends on CMD_TFTPBOOT
> @@ -2279,6 +2273,14 @@ config CMD_TFTPBOOT
> help
> tftpboot - load file via network using TFTP protocol
>
> +config CMD_TFTPSRV
> + bool "tftpsrv"
> + depends on CMD_TFTPBOOT
> + help
> + Act as a TFTP server and receive the first incoming file into
> + memory. The command returns successfully after the transfer so
> + boot scripts can boot the received image from the load address.
> +
> config CMD_WGET
> bool "wget"
> default y if SANDBOX || ARCH_QEMU
> diff --git a/cmd/lwip/Makefile b/cmd/lwip/Makefile
> index 90df1f5511c..245683a9672 100644
> --- a/cmd/lwip/Makefile
> +++ b/cmd/lwip/Makefile
> @@ -4,4 +4,5 @@ obj-$(CONFIG_CMD_NFS) += nfs.o
> obj-$(CONFIG_CMD_PING) += ping.o
> obj-$(CONFIG_CMD_SNTP) += sntp.o
> obj-$(CONFIG_CMD_TFTPBOOT) += tftp.o
> +obj-$(CONFIG_CMD_TFTPSRV) += tftpsrv.o
> obj-$(CONFIG_CMD_WGET) += wget.o
> diff --git a/cmd/lwip/tftpsrv.c b/cmd/lwip/tftpsrv.c
> new file mode 100644
> index 00000000000..6370c900489
> --- /dev/null
> +++ b/cmd/lwip/tftpsrv.c
> @@ -0,0 +1,11 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +#include <command.h>
> +#include <net.h>
> +
> +U_BOOT_CMD(tftpsrv, 2, 1, do_tftpsrv,
> + "act as a TFTP server and receive the first file",
> + "[loadAddress]\n"
> + "Listen for an incoming TFTP transfer and receive a file into
> memory.\n"
> + "The transfer is aborted if a transfer has not been started after\n"
> + "about 50 seconds or if Ctrl-C is pressed.");
> diff --git a/cmd/net.c b/cmd/net.c
> index f6f556f36ae..0f0b2386d87 100644
> --- a/cmd/net.c
> +++ b/cmd/net.c
> @@ -89,9 +89,9 @@ static int do_tftpsrv(struct cmd_tbl *cmdtp, int flag, int
> argc,
>
> U_BOOT_CMD(
> tftpsrv, 2, 1, do_tftpsrv,
> - "act as a TFTP server and boot the first received file",
> + "act as a TFTP server and receive the first file",
> "[loadAddress]\n"
> - "Listen for an incoming TFTP transfer, receive a file and boot it.\n"
> + "Listen for an incoming TFTP transfer and receive a file into memory.\n"
> "The transfer is aborted if a transfer has not been started after\n"
> "about 50 seconds or if Ctrl-C is pressed."
> );
> diff --git a/configs/qemu_arm64_lwip_defconfig
> b/configs/qemu_arm64_lwip_defconfig
> index a974970c3d3..06ed5a131db 100644
> --- a/configs/qemu_arm64_lwip_defconfig
> +++ b/configs/qemu_arm64_lwip_defconfig
> @@ -7,6 +7,7 @@ CONFIG_NET_LWIP=y
> CONFIG_CMD_DNS=y
> CONFIG_CMD_NFS=y
> CONFIG_CMD_SNTP=y
> +CONFIG_CMD_TFTPSRV=y
> CONFIG_CMD_WGET=y
> CONFIG_EFI_HTTP_BOOT=y
> CONFIG_WGET_HTTPS=y
> diff --git a/doc/usage/cmd/tftpsrv.rst b/doc/usage/cmd/tftpsrv.rst
> new file mode 100644
> index 00000000000..597a2f3a8bd
> --- /dev/null
> +++ b/doc/usage/cmd/tftpsrv.rst
> @@ -0,0 +1,73 @@
> +.. SPDX-License-Identifier: GPL-2.0+:
> +
> +.. index::
> + single: tftpsrv (command)
> +
> +tftpsrv command
> +===============
> +
> +Synopsis
> +--------
> +
> +::
> +
> + tftpsrv [loadAddress]
> +
> +Description
> +-----------
> +
> +The tftpsrv command listens for an incoming TFTP write request and receives
> +the first transferred file into memory.
> +
> +loadAddress
> + memory address where the received file is stored. If not provided, the
> + address is taken from the *loadaddr* environment variable or the default
> + image load address.
> +
> +After a successful transfer, the *fileaddr* and *filesize* environment
> +variables describe the received file. The command returns successfully after
> +the transfer has completed. It does not boot the file automatically; boot
> +scripts can use commands such as bootm, booti or bootefi to boot from the
> +load address.
> +
> +The transfer is aborted if no transfer has started after about 50 seconds or
> +if Ctrl-C is pressed.
> +
> +Example
> +-------
> +
> +In the example the following steps are executed:
> +
> +* setup the board network address
> +* receive a FIT image from a host
> +* boot the received FIT image
> +
> +::
> +
> + => setenv autoload no
> + => dhcp
> + BOOTP broadcast 1
> + DHCP client bound to address 192.168.1.40 (7 ms)
> + => tftpsrv $loadaddr
> + Using ethernet@1c30000 device
> + Listening for TFTP transfer on 192.168.1.40
> + Load address: 0x42000000
> + Loading:
> #################################################################
> + 6.5 MiB/s
> + done
> + Bytes transferred = 1048576 (100000 hex)
> + => bootm $fileaddr
> +
> +On the host, send the file to the board while U-Boot is listening:
> +
> +::
> +
> + $ curl --upload-file image.fit tftp://192.168.1.40/image.fit
> +
> +Configuration
> +-------------
> +
> +The command is only available if CONFIG_CMD_TFTPSRV=y.
> +
> +The command is supported by both the legacy network stack and the lwIP
> network
> +stack.
> diff --git a/include/net-lwip.h b/include/net-lwip.h
> index 20cb0992cce..571d8941ff0 100644
> --- a/include/net-lwip.h
> +++ b/include/net-lwip.h
> @@ -52,6 +52,7 @@ bool wget_validate_uri(char *uri);
>
> int do_dns(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
> int do_nfs(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
> +int do_tftpsrv(struct cmd_tbl *cmdtp, int flag, int argc, char *const
> argv[]);
> int do_wget(struct cmd_tbl *cmdtp, int flag, int argc, char * const argv[]);
>
> #endif /* __NET_LWIP_H__ */
> diff --git a/net/lwip/tftp.c b/net/lwip/tftp.c
> index 7f3b28b8507..af25aabc973 100644
> --- a/net/lwip/tftp.c
> +++ b/net/lwip/tftp.c
> @@ -11,6 +11,7 @@
> #include <linux/delay.h>
> #include <linux/kconfig.h>
> #include <lwip/apps/tftp_client.h>
> +#include <lwip/apps/tftp_server.h>
> #include <lwip/timeouts.h>
> #include <mapmem.h>
> #include <net.h>
> @@ -19,6 +20,8 @@
> #define PROGRESS_PRINT_STEP_BYTES (10 * 1024)
> /* Max time to wait for first data packet from server */
> #define NO_RSP_TIMEOUT_MS 10000
> +/* Max time to wait for an incoming TFTP write request */
> +#define NO_WRQ_TIMEOUT_MS (TFTP_TIMEOUT_MSECS * TFTP_MAX_RETRIES)
I don't think it makes much sense to express NO_WRQ_TIMEOUT_MS in
terms of TFTP_TIMEOUT_MSECS and TFTP_MAX_RETRIES, does it?
I suggest:
#define TFTPSRV_LISTEN_TIMEOUT_MS 50000
We could also make this configurable via Kconfig and even add
an environment variable but that may be going a bit too far.
> enum done_state {
> NOT_DONE = 0,
> @@ -34,8 +37,27 @@ struct tftp_ctx {
> ulong hash_count;
> ulong start_time;
> enum done_state done;
> + bool is_server;
> + bool wrq_accepted;
> + char fname[TFTP_MAX_FILENAME_LEN + 1];
> };
>
> +static struct tftp_ctx *tftpsrv_active_ctx;
Could we get rid of this global and allocate the context
dynamically instead?
The rest looks fine to me.
Thanks,
--
Jerome
> +
> +static void transfer_timeout(void *arg)
> +{
> + struct tftp_ctx *ctx = (struct tftp_ctx *)arg;
> +
> + printf("Timeout!\n");
> + ctx->done = FAILURE;
> +}
> +
> +static void restart_transfer_timeout(struct tftp_ctx *ctx)
> +{
> + sys_untimeout(transfer_timeout, ctx);
> + sys_timeout(TFTP_TIMEOUT_MSECS, transfer_timeout, ctx);
> +}
> +
> /**
> * store_block() - copy received data
> *
> @@ -71,7 +93,7 @@ static int store_block(struct tftp_ctx *ctx, void *src,
> u16_t len)
> ctx->size += len;
> ctx->block_count++;
>
> - tftp_tsize = tftp_client_get_tsize();
> + tftp_tsize = ctx->is_server ? 0 : tftp_client_get_tsize();
> if (tftp_tsize) {
> pos = clamp(ctx->size, 0UL, tftp_tsize);
>
> @@ -92,7 +114,20 @@ static int store_block(struct tftp_ctx *ctx, void *src,
> u16_t len)
>
> static void *tftp_open(const char *fname, const char *mode, u8_t is_write)
> {
> - return NULL;
> + struct tftp_ctx *ctx = tftpsrv_active_ctx;
> +
> + if (!IS_ENABLED(CONFIG_CMD_TFTPSRV) || !ctx || !is_write)
> + return NULL;
> +
> + ctx->wrq_accepted = true;
> + ctx->start_time = get_timer(0);
> + snprintf(ctx->fname, sizeof(ctx->fname), "%s", fname);
> + restart_transfer_timeout(ctx);
> +
> + printf("\nReceiving '%s' mode '%s'\n", fname, mode);
> + puts("Loading: ");
> +
> + return ctx;
> }
>
> static void tftp_close(void *handle)
> @@ -101,13 +136,15 @@ static void tftp_close(void *handle)
> ulong tftp_tsize;
> ulong elapsed;
>
> + sys_untimeout(transfer_timeout, ctx);
> +
> if (ctx->done == FAILURE || ctx->done == ABORTED) {
> /* Closing after an error or Ctrl-C */
> return;
> }
> ctx->done = SUCCESS;
>
> - tftp_tsize = tftp_client_get_tsize();
> + tftp_tsize = ctx->is_server ? 0 : tftp_client_get_tsize();
> if (tftp_tsize) {
> /* Print hash marks for the last packet received */
> while (ctx->hash_count < 49) {
> @@ -142,9 +179,14 @@ static int tftp_write(void *handle, struct pbuf *p)
> struct tftp_ctx *ctx = handle;
> struct pbuf *q;
>
> - for (q = p; q; q = q->next)
> - if (store_block(ctx, q->payload, q->len) < 0)
> + for (q = p; q; q = q->next) {
> + if (store_block(ctx, q->payload, q->len) < 0) {
> + ctx->done = FAILURE;
> return -1;
> + }
> + }
> +
> + restart_transfer_timeout(ctx);
>
> return 0;
> }
> @@ -204,6 +246,9 @@ static int tftp_loop(struct udevice *udev, ulong addr,
> char *fname,
> ctx.block_count = 0;
> ctx.hash_count = 0;
> ctx.daddr = addr;
> + ctx.is_server = false;
> + ctx.wrq_accepted = false;
> + ctx.fname[0] = '\0';
>
> printf("Using %s device\n", udev->name);
> printf("TFTP from server %s; our IP address is %s\n",
> @@ -258,6 +303,132 @@ static int tftp_loop(struct udevice *udev, ulong addr,
> char *fname,
> return -1;
> }
>
> +static void no_request(void *arg)
> +{
> + struct tftp_ctx *ctx = (struct tftp_ctx *)arg;
> +
> + if (ctx->wrq_accepted)
> + return;
> +
> + printf("Timeout!\n");
> + ctx->done = FAILURE;
> +}
> +
> +static int tftpsrv_loop(struct udevice *udev, ulong addr)
> +{
> + struct netif *netif;
> + struct tftp_ctx ctx;
> + const char *ipaddr;
> + err_t err;
> +
> + if (addr == 0)
> + return -1;
> +
> + ipaddr = env_get("ipaddr");
> + if (!ipaddr || !*ipaddr) {
> + log_err("error: ipaddr has to be set\n");
> + return -1;
> + }
> +
> + netif = net_lwip_new_netif(udev);
> + if (!netif)
> + return -1;
> +
> + memset(&ctx, 0, sizeof(ctx));
> + ctx.done = NOT_DONE;
> + ctx.daddr = addr;
> + ctx.is_server = true;
> +
> + printf("Using %s device\n", udev->name);
> + printf("Listening for TFTP transfer on %s\n", ipaddr);
> + printf("Load address: 0x%lx\n", ctx.daddr);
> +
> + tftpsrv_active_ctx = &ctx;
> + err = tftp_init_server(&tftp_context);
> + if (err != ERR_OK) {
> + log_err("tftp_init_server err: %d\n", err);
> + tftpsrv_active_ctx = NULL;
> + net_lwip_remove_netif(netif);
> + return -1;
> + }
> +
> + ctx.start_time = get_timer(0);
> + sys_timeout(NO_WRQ_TIMEOUT_MS, no_request, &ctx);
> + while (!ctx.done) {
> + net_lwip_rx(udev, netif);
> + if (ctrlc()) {
> + printf("\nAbort\n");
> + ctx.done = ABORTED;
> + break;
> + }
> + }
> + sys_untimeout(no_request, (void *)&ctx);
> +
> + tftp_cleanup();
> + tftpsrv_active_ctx = NULL;
> + net_lwip_remove_netif(netif);
> +
> + if (ctx.done == SUCCESS) {
> + if (env_set_hex("fileaddr", addr)) {
> + log_err("fileaddr not updated\n");
> + return -1;
> + }
> + efi_set_bootdev("Net", "", ctx.fname, map_sysmem(addr, 0),
> + ctx.size);
> + return 0;
> + }
> +
> + return -1;
> +}
> +
> +int do_tftpsrv(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> +{
> + int ret = CMD_RET_SUCCESS;
> + char *end;
> + ulong laddr;
> + ulong addr;
> +
> + if (!IS_ENABLED(CONFIG_CMD_TFTPSRV))
> + return CMD_RET_FAILURE;
> +
> + laddr = env_get_ulong("loadaddr", 16, image_load_addr);
> +
> + switch (argc) {
> + case 1:
> + break;
> + case 2:
> + addr = hextoul(argv[1], &end);
> + if (end == argv[1] || *end) {
> + ret = CMD_RET_USAGE;
> + goto out;
> + }
> + laddr = addr;
> + break;
> + default:
> + ret = CMD_RET_USAGE;
> + goto out;
> + }
> +
> + if (!laddr) {
> + log_err("error: no load address\n");
> + ret = CMD_RET_FAILURE;
> + goto out;
> + }
> +
> + if (net_lwip_eth_start() < 0) {
> + ret = CMD_RET_FAILURE;
> + goto out;
> + }
Missing call to net_lwip_eth_stop()?
> +
> + if (tftpsrv_loop(eth_get_dev(), laddr) < 0)
> + ret = CMD_RET_FAILURE;
> + else
> + image_load_addr = laddr;
> +
> +out:
> + return ret;
> +}
> +
> int do_tftpb(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> {
> int ret = CMD_RET_SUCCESS;
> diff --git a/test/py/tests/test_net.py b/test/py/tests/test_net.py
> index 27cdd73fd49..a2007c2fd3a 100644
> --- a/test/py/tests/test_net.py
> +++ b/test/py/tests/test_net.py
> @@ -59,6 +59,19 @@ For example:
> 'fnu': 'ubtest-upload.bin',
> }
>
> + # Details regarding a file that may be written to U-Boot using the
> tftpsrv
> + # command. This variable may be omitted or set to None if tftpsrv testing
> + # is not possible or desired. The test uses host-side curl TFTP support
> to
> + # upload a generated file to U-Boot. The optional tftpsrv_url entry may
> be
> + # used when the host must use a forwarded address instead of U-Boot's
> + # ipaddr value.
> + env__net_tftpsrv_file = {
> + 'fn': 'ubtest-tftpsrv.bin',
> + 'addr': 0x10000000,
> + 'size': 4096,
> + 'timeout': 50000,
> + }
> +
> # Details regarding a file that may be read from a NFS server. This
> variable
> # may be omitted or set to None if NFS testing is not possible or
> desired.
> env__net_nfs_readable_file = {
> @@ -89,6 +102,8 @@ import utils
> import uuid
> import datetime
> import re
> +import tempfile
> +import zlib
>
> net_set_up = False
> net6_set_up = False
> @@ -460,3 +475,82 @@ def test_net_tftpput(ubman):
>
> output = ubman.run_command("crc32 $fileaddr $filesize")
> assert expected_tftpb_crc in output
> +
> +
> [email protected]("cmd_crc32")
> [email protected]("cmd_tftpsrv")
> [email protected]("curl")
> +def test_net_tftpsrv(ubman):
> + """Test the tftpsrv command.
> +
> + A file is generated on the host, uploaded to U-Boot using TFTP and then
> + validated in U-Boot using its size and CRC32.
> +
> + The details of the file to upload are provided by the boardenv_* file;
> + see the comment at the beginning of this file.
> + """
> +
> + if not net_set_up:
> + pytest.skip("Network not initialized")
> +
> + f = ubman.config.env.get("env__net_tftpsrv_file", None)
> + if not f:
> + pytest.skip("No tftpsrv file to write")
> +
> + curl_version = utils.run_and_log(ubman, ["curl", "--version"])
> + if "tftp" not in curl_version.split():
> + pytest.skip("curl does not support TFTP")
> +
> + addr = f.get("addr", None)
> + if not addr:
> + addr = utils.find_ram_base(ubman)
> +
> + timeout = f.get("timeout", ubman.p.timeout)
> + timeout_secs = max(1, (timeout + 999) // 1000)
> + size = f.get("size", 4096)
> + fn = f.get("fn", "ubtest-tftpsrv.bin")
> + url = f.get("tftpsrv_url", None)
> + data = bytes([i % 251 for i in range(size)])
> + crc = "%08x" % (zlib.crc32(data) & 0xffffffff)
> +
> + ip = ubman.run_command("echo $ipaddr").strip()
> + if not ip:
> + pytest.skip("No U-Boot IP address")
> + if not url:
> + url = "tftp://%s/%s"; % (ip, fn)
> +
> + with tempfile.NamedTemporaryFile() as tmp:
> + tmp.write(data)
> + tmp.flush()
> +
> + done = False
> + with ubman.temporary_timeout(timeout):
> + try:
> + ubman.run_command("tftpsrv %x" % addr,
> + wait_for_prompt=False)
> + ubman.wait_for("Listening for TFTP transfer")
> + utils.run_and_log(
> + ubman,
> + [
> + "curl",
> + "--fail",
> + "--max-time",
> + str(timeout_secs),
> + "--upload-file",
> + tmp.name,
> + url,
> + ],
> + )
> + ubman.wait_for("Bytes transferred = %d" % size)
> + ubman.wait_for(ubman.prompt)
> + done = True
> + finally:
> + if not done:
> + ubman.ctrlc()
> + ubman.drain_console()
> +
> + output = ubman.run_command("echo $filesize")
> + assert "%x" % size in output
> +
> + output = ubman.run_command("crc32 $fileaddr $filesize")
> + assert crc in output
