The hongyavision HYWS-SGT0204S is sold as an unmanaged 4x2.5G + 2x10G SFP+
switch and carries the 2G5F4_10G2_V1.01 marking on the PCB. It is a sibling of
the KP-9000-6XH-X2 (2M-PCB43-V1.1), so machine/2G5F4_10G2_V1_01.c is that board
definition with these changes:
- The two SFP+ cages (physical ports 5 and 6) are wired the other way round:
physical 5 is on SDS1 with GPIO30/GPIO37, physical 6 on SDS0 with
GPIO50/GPIO10. Copper ports 1-4 match the KP-9000 layout.
- No reset button is fitted and the case has no opening for one, so reset_pin
is GPIO_NA. GPIO54, the reset pin on the KP-9000 layout, reads as permanently
pressed here.
- The board definition sets flash_sio, so the flash is read with single-IO: the
fitted 512 KB Bright Moon T25S40 cannot be read in DIO mode on this board, an
image that leaves DIO enabled does not come up at all, while the same image
with single-IO boots and runs normally (two units).
- The board is added to the machine_custom_init() group that sets
LED_GLB_IO_EN bit 6, otherwise the RTL837x "solid" conditions (LINK/speed)
never drive the LEDs and the 2.5G LED glows faintly at 100M/1000M.
flash_sio is a new field of struct machine that rtlplayground.c hands to
flash_init(); only this board sets it, every other machine keeps DIO. It costs
management-plane speed only, the ASIC keeps forwarding in hardware.
The stock firmware runs a factory test console on the serial header at 9600
baud, whose silkscreen labels are shifted by one pin.
Verified: warning-free build, `make machine_check` passes for every target, the
host tests pass, and a control build of this target without the LED hook differs
from the KP-9000-6XH_X2_V1_1 image in 44 bytes: all inside the machine
description (including flash_sio) and the image CRC16, nothing else in the
firmware moved. On the board the single-IO image boots and runs on two units;
port order, SFP cages and LED behaviour come from the machine definition
verified on this board earlier.
"port <port> cabletest" runs the cable diagnostic of the copper PHYs
and reports one line per pair: ok, or open, short, short to another
pair or impedance mismatch with the distance to the fault.
The PHY part follows the cable_test_start and cable_test_get_status
ops of the Linux phy_driver and takes the port number:
rtl_phy_cable_test_start() triggers the test and
rtl_phy_cable_test_get_status() returns true once all four pairs are
done, with a result code and a length per pair. The decode order is
the one of the Linux driver. The same two functions drive the RTL8224
and the internal PHYs of the RTL8372 and RTL8373.
The command only powers the port down and returns. A state machine
called from handle_tick() calls the start op after one second, polls
the status op, stores the result, clears the trigger, also after a
timeout, and restores the control register, so the main loop never
waits. The result is printed when it is ready and "port <port>
cabletest show" prints it again. One test runs at a time.
The result flags are the low byte of the per-pair status word. The
vendor code reads the high byte, which is always zero on the RTL8373.
A link partner that keeps transmitting makes the PHY report an
inter-pair short on every pair, and forcing the speed with
autonegotiation off, as the Linux driver does, does not take the link
down. The port is therefore powered down for a second before the
test. The control register is restored afterwards with an
autonegotiation restart, so speed settings survive and the link
returns.
A test started on a port that is switched off never finishes and
leaves the PHY unusable until the switch is reset, so such a port is
refused, and a test is dropped if the port is switched off during the
wait. SFP ports are refused by the existing check. The external copper
PHYs of the RTL8372 boards are refused because the test has not been
run on one.
The distance is the raw length word minus 150, at 43 counts per 50 cm.
Fitted on open cables of 0.9 m, 2 m and 7.6 m; the pairs of one cable
differ by about 0.2 m. The Linux formula, raw minus 620 at 78 counts
per metre, gives 0, 0 and 2.4 m for these cables.
An unplugged port has no defined result: some pairs report open at
about 0.5 m and others a short or a mismatch at 2 to 3 m.
The comments repeated the documentation, described tests or explained
the code to its author. What stays describes the LACPDU structures. The
timer constants are decimal, in units of the LACP timer.
lacp_in() always leaves uip_len at 0, so the tcpip_output() after it
never ran. The LAG page names the active members by front-panel port
instead of a logical mask. The partner key is not part of selection;
say so under Known limits.
Dynamic link aggregation on top of the static LAGG, for RTL8372/8373:
receive, selection and mux state machines (coupled mux, one aggregator
per group), with "lacp show" to look inside. Each of the four trunk
groups runs its own aggregator on the candidate ports assigned with
"lag <n> lacp <ports>"; the engine starts with the first such group and
stops with the last.
LACPDUs reach the CPU through the reserved-multicast trap, so delivery
needs no L2 entry and nothing written per VLAN or per PVID. The trap
acts on the address before the VLAN lookup and before the ingress
filters, so a LACPDU also arrives on a port that admits tagged frames
only and on a port STP holds in blocking, neither of which a forwarded
one reaches. A trapped frame carries no VLAN tag,
so lacp_in() takes the offset of the PDU body from TRAP_RX_BODY(). The
action is set with trap_rma_set(), which leaves the flags sharing that
register alone, and "lacp off" puts the slow-protocols drop default
back. doc/lacp.md and doc/link_aggregation.md record what was measured,
including why the trap looked like a dead end at first.
The web UI gets a Static/LACP mode per group on the LAG page with live
status, and the startup-config validator knows the per-group syntax. A
host-side sandbox for the state machines runs in the test harness
together with the LAG hash check. It drives both forms of an incoming
LACPDU, so the body offset of a trapped one is covered as well.
The L2 table page iterated with the "next unicast" read method, so
static multicast entries such as an IGMP group were invisible. It now
iterates with "next address", skips L3 entries (their layout carries IP
addresses where a MAC is expected), and reports the lowest member of a
multicast entry's port mask, so such an entry shows up as a static
entry on that port.
A port taken out of LACP forgets its partner, so "lacp show" after
"lacp off" no longer reports one. Applying the same candidate set to a
group again, as the LAG page does on every Apply, leaves the trunk
alone instead of tearing it down for a second or two. lacp_in() checks
the frame length and ethertype before reading a LACPDU, so a runt or a
foreign frame on the slow-protocols address cannot leave stale buffer
bytes as a partner. The sandbox covers these three in T20-T22. On the
LAG page, LACP mode with no ports checked sends "lag N lacp off", and
the startup-config validator wants at least one port after "lacp".
A reserved-multicast trap goes to the port named in EXT_CPU_CTRL, which
names no port out of reset, so trapped frames were dropped at ingress.
trap_init() points it at the CPU port once at startup, and
trap_rma_set() changes only the action field of an RMA register.
A trapped frame arrives without the VLAN tag a forwarded one gets, so
TRAP_RX_BODY() gives the offset of the payload for both forms.
STP now traps its address while it runs instead of steering it with a
static L2 entry per VLAN, so turning it on no longer walks the VLAN
table and a pvid change no longer needs stp off and on. With STP off
the flooding entries are restored as before.
A trapped BPDU passes the tagged-only ingress filter that drops a
forwarded one, so the stp_setup() warning about such ports goes.
timing with ticks
Fixing up the log_to_phys_port assignment
2000 is about every 10 seconds, so scaling up to once every 30ish
Removing the attempt to block lldp frames,
This does not work however the hard work has been done for us in
the #514 so we can borrow that work later on
to each port once every 30 seconds.
* Additionally fixes the on-ward passing of LLDP frames through
the switch
The ports on the case are marked 1-8 so this should reflect that
rather than being 0-based
We can send the hostname as well, this can be dynamically allocated
Let's send the model as the system description as well
leds_dump() printed the pin mux, the LED enables and every LED set on each
boot, from BANK2. It now lives in its own file in BANK3, where there is
room, and runs only on the new "leds" command, next to gpio and sds, so it
stays at hand for bringing up a new board without costing BANK2 or boot
output.
494320b removed strcpy() from rtl837x_flash.c but left its declaration
in rtl837x_common.h. Since then the linker has taken strcpy from the
SDCC library instead, which expects the destination as a generic pointer
in DPL, DPH and B. The callers pass an __xdata pointer and leave B as it
is, so the copy lands wherever B happens to point. boot.c only gets away
with it because B is zero there; a call with B set, as from the ChaCha20
test in #207, writes into internal RAM and stops the 8051.
Only frames to 01:00:5e:00:00:16 reached the IGMP handler, so v1/v2
reports, which go to the group address, were never seen. The handler
also took the group from the first v3 group record for every type.
Pass all IPv4 multicast to the handler, which takes the IGMP header
from the IP header length, the group from the IGMP header for v1/v2
reports and v2 leaves and from the first group record for v3, and
returns 0 for anything that is not IGMP so it goes on to the IP stack.
The message and record types have names now.
The switch has no battery backed clock, only a seconds counter that starts
at zero on every boot. An SNTP client keeps UTC as the time of the last
answer plus the seconds counted since: "ntp server <name|ip>", "ntp interval
<minutes>", "ntp timezone <+hh:mm>", "ntp dst off|eu|us", "ntp on|off",
"ntp" and "time". A server given by name goes through the DNS resolver, an
answer from an unsynchronised server is ignored, and a failed attempt is
repeated after 30 seconds.
The local time adds the time zone offset and, while the European or United
States rule says so, one hour. The date is split with a shift and subtract
division and a walk over the years, so no 32-bit division from the library
ends up in the common area.
The System page gets the NTP settings and shows the local time.
A small resolver for IPv4 address records, so that clients such as NTP can
be given a host name: "dns server <ip> [<ip>]", "dns lookup <name>" and
"dns". Without a configured server it uses the one DHCP handed out. A query
goes to the servers in turn every two seconds and gives up after six tries;
answers with compressed names and CNAME records ahead of the address are
understood. A name that already is a dotted address is taken without a
query.
The resolver sits in BANK3, the command line in BANK2 next to the helpers it
uses. The System page shows and sets the servers.
The main loop drains the NIC only after an RX interrupt, at most
RX_BUDGET frames, then clears the status and waits for the next one.
When frames are left and the buffer reaches the RX stop threshold, the
NIC takes no more frames and raises no further interrupt, so reception
stops for good.
Check the buffer after clearing the status and keep draining while it
holds data; the interrupt is re-enabled only once it is empty.
rtl8224_enable() waits 2.5 s after releasing the RTL8224 reset before
anything talks to the PHY. On an SWTGW218AS the chip id already reads
back 0x8224 at the first poll, about 265 ms after the release.
Remember when the reset was released and, once SMI is up, poll the chip
id until it answers, giving up after the same 2.5 s as before. The PHY
writes that follow read back the same as before.
The reset pulse before it goes from 0.5 s to 20 ms, twice the 10 ms the
related RTL8372 and RTL8221B need. The pulse does reset the chip: the
MDI reverse register (MMD 30, 0x0a90) still reads its power-on value
0x00f3 just before the init writes 0x00fc, as it does with 0.5 s.
Together the console banner comes 3 s sooner.
The SerDes write loop in phy_config_8224() waited on the busy bit with
no limit, so a PHY that never answers stopped the boot before the
network came up. Bound it and report a timeout.
The receive interrupt was wired up but never used: EX1 was enabled, the
handler re-enabled itself and did nothing, and the mask bit for it in the
NIC stayed clear, so idle() read the receive buffer register on every
pass to find out whether a packet had arrived, and slept until the next
tick when none had. A packet that arrived during that sleep waited for
the tick: 2.2 ms on average, 5 ms at worst, for every frame the CPU
handles.
Now the handler latches rx_irq and masks itself, and idle() sleeps
unless a receive, a link change, a console command or the tick is
pending. On rx_irq the loop drains the buffer, clears the status bit and
re-enables EX1, in that order: the NIC holds the line as long as the
status bit is set, and the bit does not clear while the buffer still
holds a frame, so a frame that lands between the last read and EX1 = 1
raises the interrupt again rather than getting lost. The other order,
clearing before draining, left the line asserted and produced an
interrupt on every pass. The mask is written after nic_setup(), which
resets it.
Measured on an RTL8373 board with the same counters in both images,
clocked by the tick counter, traffic from a host behind an LACP trunk:
```
polling interrupt
idle, register ops/s 788 79
25 pps, RTT avg/max 2.19/4.96 0.44/0.75 ms
500 pps, RTT avg/max 2.78/5.06 0.39/5.40 ms
500 pps, loss 0.08% 0.08%
```
The handler compiles to clr EX1 / setb rx_irq / reti.
The timer interrupt now raises a tick flag too, so idle() no longer works
out TICKS_DUE twice per pass, and cmd_available moves from xdata to a
bit. The four wake-up flags sit in the low bits of one byte at 0x20, so
the sleep test is a single read of that byte. tx_buf_empty deliberately
stays out: it is 1 when there is nothing to do, so including it would
keep the sleep test from ever firing.
idle() ran everything on every pass: the seconds block, the SFP pin
test, the TCP periodic timer behind a gate of its own, the STP timers
behind theirs. The timed work moves into handle_tick(), which idle()
calls once per system tick from a single gate; handle_tx() loses its
private one.
handle_sfp() ran on every pass as well, two GPIO reads per pass to learn
that nothing changed; it now runs every ten ticks. A module inserted is
still seen within 50 ms, and the read itself has been off the loop since
the wake-up wait moved to the tick.
No change in behaviour otherwise: the link, receive and console paths
stay where they were. SWTGW218AS: code +45 B, xdata +1 B, stack
unchanged.
The health checkpoints follow the work they measure: the seconds block,
SFP, TX and STP phases are taken inside handle_tick(), the link, RX and
command phases in idle().
The link-change interrupt was set up at boot (mode 0x5f84, mask 0x5f34)
but never enabled: the handler did nothing and did not clear the event in
the switch, so EX0 stayed commented out and idle() read the two link
registers on every pass instead, 400 reads a second on a quiet switch.
The handler now only latches a flag and masks itself; the register access
macros build a write in the shared SFR data bytes, so an interrupt that
touched the switch in the middle of a write from the main loop would
corrupt it. idle() clears the event register (write-one-to-clear, 0x3ff
for the ten ports), re-enables EX0 and then reads the link state, in that
order, so a change that lands during the read raises a new edge. The flag
is also set once a second from the seconds block, so a board whose INT0
line turns out not to be wired keeps detecting link changes, a second
late at worst. Boot drops the events pending from bringing the links up
before the mask is set.
Measured on an RTL8373 switch before this change: 0x5f88 held 0x3fd, nine
ports had reported a change nobody read. With the change a counter in the
loop went 2 -> 3 -> 4 on "port 5 off" / "port 5 on" and stayed at 4 over
three reads without events, so the event is delivered, cleared and
re-armed, and there is no flood.
SWTGW218AS: code +57 B, xdata 0, stack 151 -> 150 B; the flag is a bit
variable. The handler compiles to clr EX0 / setb link_irq / reti.
idle() also keeps in a bit what it saw in NIC_RX_BUFF_DATA when deciding
whether to sleep, and the first iteration of the receive loop uses it
instead of reading the register again a moment later. Between the two
only the link check and handle_sfp() run, and neither can make a queued
packet disappear. Every later iteration reads the register as before, so
the budget loop behaves as it did. This part was not measured on
hardware: one register read per pass needs a throughput run to show up.
SWTGW218AS: BANK1 and BANK2 +6 bytes each, BANK3 unchanged.
stp_timers() ran every fourth pass of the main loop and stp_clock counted
passes, which only measures time while a pass is one tick long. It never
quite was: a pass is as long as the packets it handles, and #482 now takes
up to four of them, so under an IPv4 stream a pass is about 16 ms and STP
time runs at a third of its rate, with hellos 6 s apart and a root aged out
after a minute. Since #483 the loop also stops sleeping while packets wait,
so under a flood of cheap frames passes come faster than ticks and STP time
runs fast instead, shortening the forward delay in exactly the situation a
loop produces. uip_periodic() had the same problem from the other side: it
ran once per pass, so the retransmit timer sped up with the loop.
Both now go by the tick counter the timer interrupt keeps. The STP block
catches up on ticks a long pass missed, at most eight steps at a time, and
handle_tx() runs its periodics once per tick at most. One byte of xdata
more, 48 bytes of code.
A host test drives the gate with one pass every 5 ms, every 16 ms and
every 0.6 ms for ten seconds each; the STP clock lands on 500 steps in
all three, where counting passes gave 156 and 4166. A pass of 1.3 s loses
time rather than firing 65 steps at once, and the arithmetic survives the
tick counter wrapping.
The counters, the phase hooks in idle() and the "health" command are now
behind HEALTH, set from the command line with HEALTH=1. Without it the
hooks are empty macros and the command does not exist, so a default build
carries none of it: on SWTGW218AS that is 1065 bytes of bank 2, 101 of the
common segment and 28 of xdata, plus seven banked calls per main-loop pass.
It is a developer's tool. Reading the dump takes knowing the main loop, and
a user who needs it for a report can build with the flag on, which is how
the kernel treats its lock and latency instrumentation as well.
Every probe of a misbehaving switch so far measured it from the
outside. This puts the witnesses inside.
Each idle() pass increments a loop counter and stamps a checkpoint
after every phase: link polling, SFP, RX, TX, STP and the command
dispatch. A phase spanning two or more system ticks counts as slow and
its worst time is kept, in 5 ms units. handle_rx counts frames, so the
dump separates a flooded CPU from a stalled loop.
At boot the free stack area is painted, preserving the interrupt state
around the painting, and the dump reports how much of the pattern
survives next to the live stack pointer. The TCP connection table is
printed whole: state, timers, retransmissions, ports and peer, next to
the httpd transfer state, so a permanently occupied slot names its
occupant. With more than one slot configured every slot is listed.
Everything is raw hex; two dumps a known time apart give the rates.
The implementation sits in cmd_parser next to the other command
handlers and needs no storage beyond its counters.
Building with SDCC 4.6.0 emits tons of warnings e.g.:
cmd_parser.c:31: warning 356: object in read-only code space should be const
cmd_parser.c:36: warning 357: pointer to object in read-only code space should be pointer to const
These of course become fatal when building with --Werror.
Comparing resultant binaries, it seems that a single string is shifted
(deduplication?) but the numbers emitted at the end of the build are
otherwise identical.
idle() went to sleep before it looked at the receive buffer, so a packet that
arrived just after the loop dozed off waited for the next tick before anything
touched it. Every TCP round-trip paid that toll, which is why the web UI felt
sluggish even though no phase of the loop was anywhere near busy.
Check the receive buffer first and only sleep when it is empty. The read takes
its result straight from SFR_DATA_U16 rather than going through reg_read_m()
and the sfr_data[] copy, which is what the rest of the tree already does.
Measured on SWTGW218AS with this change alone:
web UI, median of 15 requests for the main page 88 ms -> 76 ms
CPU port under a one-way UDP stream 159 -> 230 packets/s
The loop still sleeps normally when there is nothing to do, so this does not
turn the core into a busy-wait: loops/ticks stays at 0.99 on an idle switch,
and rises above 1.0 only while packets are actually queued.
Costs 12 bytes of code and no extra XDATA.
handle_rx() picked up exactly one packet per iteration of the main loop. Since
the loop sleeps until the next tick, that capped the CPU port at roughly one
packet per tick no matter how little work it had to do. A burst of broadcast,
ARP or IGMP traffic aimed at the CPU queued up behind that and pushed out the
STP and LACP timers.
Drain up to RX_BUDGET packets in one pass instead. The budget matters: without
one a sustained flood would spin here and starve everything else in the loop.
The two register reads in the loop take their result straight from
SFR_DATA_U16 rather than going through reg_read_m() and the sfr_data[] copy,
which is what the rest of the tree already does.
Measured on SWTGW218AS with a one-way UDP stream, counting the packets the CPU
actually processed, with this change alone:
before 159 packets/s
RX_BUDGET 4 245 packets/s, loop iteration ~16 ms
RX_BUDGET 8 298 packets/s, loop iteration ~26 ms
Throughput is already most of the way there at 4, so the larger budget mostly
buys a longer worst-case delay for the other phases. STP stayed responsive in
both cases.
Costs 71 bytes of code and no extra XDATA.
boot.c calls it from BANK3 and only rtlplayground.c had a prototype, so
the compiler saw an implicit declaration. The call itself was fine, the
function lives in the common area, but the warning was real. Move the
prototype into the shared header.
Reported by vDorst.
sfp.c takes handle_sfp, sfp_module_read, sfp_apply_quirks, sfp_get_info,
sfp_read_field, sfp_print_info, setup_sfp_gpio, the quirk table and the module
state that goes with them. Everything exported is __banked: handle_sfp() and
sfp_print_info() are reached from cmd_parser.c in BANK2, the rest from the
common area, and both are bank boundaries.
The quirk table needed checking rather than assuming. Its entries are __code
pointers, and a __code pointer carries no bank, so passing one to a function in
a different bank hands it an offset read through the wrong window. That is safe
here because strcmp() sits in the common segment at 0x51f and is reached with a
plain lcall, so the bank register still says 3 while it runs. Verified in the
built image: the table at 0x35580 holds 0x563c and 0x5644, which resolve to
"QSFPTEK" and "QT-SFP+-T" inside BANK3.
Common segment 13393 -> 8432 bytes, leaving 7492 free rather than 2531. BANK3
holds 5710, BANK1 is unchanged and BANK2 grows by 31 for the trampolines.
All 34 machines in machine.h build and link, and the same walk over the
generated assembly finds no plain lcall crossing a bank boundary.
The common segment is the scarce one: sixteen kilobytes shared by every bank,
and before this it had about 2.5 kB left. Most of what moves here runs once at
startup and does not have to sit in it. The two SerDes helpers are the
exception: the link-change handler and the SFP polling both reach sds_config()
while the switch is running, so they are not startup-only. None of it is
reached from an interrupt.
boot.c takes setup_i2c, init_smi, nic_setup, rtl8373_revision, rtl8224_enable,
early_boot_handle_button, set_hostname_default and the two SerDes helpers.
BANK3 is enabled with the linker flag; nothing else in the build needed
changing.
Everything moved is declared __banked, since every caller is outside BANK3:
main() and friends run from the common area and rtl837x_init.c calls
sds_config() and sds_config_mac() from BANK2. The calls the moved code makes
outward were already banked, so that side needed no work.
Common segment 13393 -> 10137 bytes, leaving 5787 free rather than 2531.
BANK3 holds 3732. All 34 machines in machine.h build and link. Walking
the generated assembly for plain lcalls that cross a bank boundary finds none
among 2808 calls; those build cleanly and only fail at run time, so it seemed
worth checking by machine rather than by eye.
The lookup tables live in BANK1, so the routine switches the code bank to
reach them with movc and never switches it back. That is the contract the
__naked declaration already implied: same bank or common segment only.
The name now says it.
crc16_bank1 is the routine unchanged. crc16 becomes a __banked wrapper in
BANK1, so a caller from another bank has its own bank put back by
__sdcc_banked_ret. The two existing call sites take the direct path and
pay nothing.
isr_ext2() ends with PCON |= 1, putting the core to sleep from inside an
interrupt handler.
The DW8051 leaves idle when any enabled interrupt is activated, so the core
does not stay down for long. It naps until the next enabled interrupt request
turns up, with the 200 Hz system tick putting a ceiling of 5 ms on that, and
then carries on.
The sleep buys nothing either way, because the instruction after it is the
return. While it lasts the handler holds the priority latch, so everything at
its level or below waits, and that includes the tick, the console and the NIC
receive interrupt.
The handler still clears its flag, which is what it has to do. The bit numbers
beside the two masks were wrong: 0xef clears bit 4 and 0xdf clears bit 5,
not 7 and 6.
isr_ext2() ends with PCON |= 1, putting the core to sleep from inside an
interrupt handler.
The DW8051 leaves idle when any enabled interrupt is activated, so the core
does not stay down for long. It naps until the next enabled interrupt request
turns up, with the 200 Hz system tick putting a ceiling of 5 ms on that, and
then carries on.
The sleep buys nothing either way, because the instruction after it is the
return. While it lasts the handler holds the priority latch, so everything at
its level or below waits, and that includes the tick, the console and the NIC
receive interrupt.
The handler still clears its flag, which is what it has to do. The two wrong
comments next to the masks go as well: 0xef clears bit 4 and 0xdf clears bit 5,
not 7 and 6, and the masks already say that without help.
Add a `mac <aa:bb:cc:dd:ee:ff>` console command (and a bare `mac` to show
the current address) that overrides the management MAC at runtime. The
address is validated (unicast, globally administered, non-zero OUI) and
the static L2 management entry is re-registered so the change applies
without a reboot. Because it is a normal command, a line in the startup
config persists it across boots: execute_config() runs it before the final
static L2 entry and the derived hostname are set up.
Also point the keepLink KP-9000-9XHML-X V3.1 machine definition at the
factory MAC area (0x1FC000, same location other machines use) so a valid
factory MAC is picked up at boot instead of falling back to a locally
administered address.
The MAC parsing/printing lives in parse_mac()/print_mac() helpers next to
parse_ip()/print_ip() so future commands can reuse them, and a memcmp()
helper joins the project's own memcpy()/memset() (no libc is linked).
isr_ext2() ends with PCON |= 1. On the DW8051 any enabled interrupt request
ends idle, so the handler sleeps until the next request arrives, the system
tick at the latest, and only then returns. Everything at the same priority
waits with it, and the instruction after the idle is RETI, so the sleep buys
nothing.
The handler still clears its flag, which is what it has to do. The other four
uses of PCON |= 1 are in task context and are left alone.
uip_arp_ipin() is an empty macro with its body under #if 0, both inherited
from the uIP import and untouched since. That leaves uip_arp_update()
reachable only from uip_arp_arpin(), so an entry is refreshed only by ARP
addressed to us and ages out after UIP_ARP_MAXAGE no matter how much traffic
passed over it.
When it goes, the next transmission to that host hits the miss path of
uip_arp_out(), which overwrites the packet in uip_buf with an ARP request and
returns. For TCP that costs a retransmission. For UDP nothing retransmits, and
handle_tx() sends the UDP connections through uip_arp_out() too, so the
datagram is lost.
The body could not be enabled as written: uip_len -= sizeof(struct uip_eth_hdr)
is a leftover from when UIP_LLH_LEN was 0. Here it is ETHER_HEADER_SIZE +
RTL_FRAME_DESC_SIZE and uip.c reads the IP header at uip_buf[UIP_LLH_LEN], so
uip_len has to keep the link layer in it. The rest of the function is sound.
write_char() masked writeptr and never looked at readptr, so once more
than LOGBUF_SIZE bytes were written between two drains the ring wrapped
over content that had not been sent yet.
That is not a corner case. The ring is emptied once per main loop pass,
while a single command runs to completion inside one pass, and a full L2
listing prints well over twice the 512 byte buffer. On hardware the whole
1227 byte dump came out as one 174 byte datagram whose first line began in
the middle of a MAC address.
Drop the character when the ring is full instead of overwriting, so what
has been logged stays intact and it is the tail that is lost. A full ring
also flags a line, otherwise a burst without a newline would leave the
reader waiting on line_available forever and syslog would stop for good.
logicog
Victor
HL Yi
bloqaudio
d00f
René van Dorst
Rob Emery
feelfree69
Matt Merhar
gnacho