azonenberg

azonenberg, 17 hours ago

@whitequark Closest I've seen to that so far is america's army 2.x (never played the newer versions much/at all so can't comment):

• When reloading a magazine-fed weapon with one in the chamber, you get an extra round (e.g. 30+1 for an M16)

• The bolt-action M24 sniper rifle models individual-round reloading correctly

• Removed mags are kept and counted, so you might reload after an intense firefight and have only a bunch of half-full mags

• Grenades from the M203 have a short range safety and won't go off if they hit something too close

• The RPG-7 and AT-4 correctly model projectile self-destruct, if you fire off into open space far enough away the round blows up mid flight at some set distance. They also model drop and have adjustable-range sights, as does IIRC the M320 in AA3 (but not the M203 in AA2).

• The M9 pistol slide locks back on an empty mag and your character does a "slingshot" slide release. Can't remember if they modeled this for the M4/16 or not.

• Breathing is modeled reasonably well.

But there's some bugs too: IIRC if the pistol jams on the last round in the mag, the slide will drop rather than locking back after you eject the dud cartridge. And I think the reload animation for the (belt fed) M249 doesn't show a partial-length belt if you have only a handful of rounds left, although I think they do have two animations for reloading from "mostly full" and "empty".

And all of the small arms are hitscan.

azonenberg, 17 hours ago

@whitequark They also model three stances (standing/crouching/prone) plus movement with accuracy affected by each, as well as a bipod you can deploy when prone to get maximum accuracy.

Accuracy is also impacted by health status and heart rate, so for example if you sprint somewhere then dive into prone, or have a whole bunch of enemy fire narrowly miss you, your accuracy will be garbage for a bit.

azonenberg, 17 hours ago

@whitequark The damage model for all of the AA games was pretty good as well, you'd take some initial damage on a hit then a lot more over time from bleeding (the percentage of each would depend on the type of injury and where you got hit).

You have a field dressing you can apply to slow (but not completely stop) bleeding but a medic-trained teammate has to treat you to fully stop it.

Rounds will go through players or many objects in the game world although they lose energy and IIRC might deflect slightly.

azonenberg, 17 hours ago

@whitequark IIRC AA3 also improved the damage model to account for limb vs torso hits having different effects on your performance (e.g. a leg injury, even if treated, reduces your movement speed while an arm injury impacts your accuracy more). But I could be wrong, I never played 3 much.

2.x had a single global HP value, the only time the damage model accounted for location was when calculating damage caused by a hit.

Oh, and grenades actually did (range limited) hitscan modeling for individual fragments to calculate damage, including reduction of damage by cover slowing down/blocking them.

azonenberg, 17 hours ago

@whitequark The Long Dark has a well modeled rifle in this regard. It's an old Lee-Enfield that takes two five-round stripper clips in a ten round mag.

On the rare occasions you find enough ammo to reload five or ten rounds at a time you'll use 1-2 clips. For anything else, you're pushing in single rounds one at a time.

But we're talking post-apocalyptic survival here, not FPS, so ammo is scarce and combat is best avoided. The bow and arrow is much more renewable (not infinitely as maple saplings for the bow and birch for the arrow shafts spawn in finite quantity in the game world, but they're far less scarce than ammo and materials for crafting more).

azonenberg, 17 hours ago

@whitequark (TLD seems like your kind of game... In survival mode everything is trying to kill you, including the weather. Except some of the animals you can eat)

azonenberg, 17 hours ago

@whitequark Speaking of weather it's quite realistically modeled since it's one of your main threats (hypothermia will kill you faster than pretty much anything but a bear or wolf attack).

There's an ambient temperature plus wind chill and precipitation. Every piece of clothing has a certain level of insulation and windproofness, as well as waterproofness. Wet clothing is far less warm and also can soak through to layers underneath.

Skin left exposed to freezing weather, or touching wet clothing that's left outside long enough to freeze, can develop frostbite which gives you a permanent health reduction.

Carrying a heat source warms you slightly, but road flares are non renewable and extremely scarce, oil for your lamp has to be looted or rendered from cooked fish, and torches can be blown out by the wind.

Oh, and clothing wears over time and can be damaged by animal attacks, snagging on things during a fall, etc. And can be repaired with a sewing kit or (more slowly) with crafted materials. And worn clothing has less insulation etc.

azonenberg, 16 hours ago

@alloydflanagan I have close to 1K hours and recently completed the last achievement (survive 500 in-game days).

It's my main game these days. definitely recommended.

azonenberg, 1 day ago

@bl0x I didn't even know it was on by default.

azonenberg, 1 day ago

@tef I felt a great disturbance in the Force, as if millions of ITAR/export compliance lawyers cried out in terror and were suddenly silenced.

azonenberg, 2 days ago

@Stormgren My azonenberg/latentpacket repo has all of the networking stuff but yeah I probably need to update the high level project docs.

The high level goal is a layer 2 (to start), possibly with some layer 3 functionality in the future, switch that's simple, no frills, and fast.

I don't need support for 30 different kinds of multicast routing and DECnet and AX.25 and IPoAC.

Just give me a basic, 1990s style fixed function CAM ASIC style, switch with as few features and as little attack surface as possible, but also modern 10/25G interface support and good power efficiency.

So the vision is a switch with a dedicated 1000baseT SSH management interface and RS232 console port connected to the management CPU, while all switch fabric ports are completely independent of management and cannot talk to the management engine (there will be no "slow path", the CPU cannot see traffic going to/from switch ports).

I don't need a lot of bells and whistles. Just port based VLANs, 802.1q, ability to force ports to specific speed and maybe duplex states, access to diagnostics like performance counters and error rates, and probably eventually some kind of port mirror/capture capability.

azonenberg, 2 days ago

@Stormgren LATENTPINK was the scaled down R&D testbed (which is switching packets now including port VLANs and inbound 802.1q, but has incomplete support for outbound 802.1q tag insertion) with only 12 ports and a single SFP+ uplink.

This used a Kintex-7 FPGA (XC7K160T) but it filled up fast enough that I didn't think I would be able to fit my initial 24 port goal into the same space.

The new concept for LATENTRED scales up to an UltraScale+ FPGA and 36-48 ports (dependent on which FPGA I go with, as well as exact details of things like front panel layout).

azonenberg, 2 days ago

@Stormgren Yeah I have plans for higher end hardware with at least 100G on it, but that's going to be the successor (LATENTORANGE). Mix and speed of ports is TBD.

I plan to build two LATENTRED systems to replace my four aging Catalyst 2970G's, then at some point in the indefinite future after that, replace my Nexus 3064X with a LATENTORANGE.

azonenberg, 2 days ago

Almost done with the APB refactoring despite lots of other things going on keeping me from spending a lot of time on it.

Now at 40% LUT load so plenty of room to expand for new features (in particular, CDR triggering) in the future.

Purple on south edge = Curve25519 accelerator

Pink at north area: debug ILA, currently looking at CDR trigger signals in anticipation of me actually implementing CDR trigger functionality at some point

Dark blue mostly in northeast: BERT / CDR trigger subsystem

Light blue: Ethernet MAC/PCS logic

Green: actual trigger crossbar muxing (tiny portion of overall logic, lol)

Red = management logic (QSPI bridge, legacy bus logic, FIFOs for MCU Ethernet TX/RX)

Brown = low speed APB peripherals (tachometers for fans, front panel SPI bus interface, etc)

Still some additional refactoring and code cleanup pending, plus converting the 1000baseT TX FIFO, the shared Ethernet RX FIFO, and the interrupt status register to APB. Hoping to get that done in the next couple days.

azonenberg, 1 day ago

@FenTiger In my case, the accelerator block is mostly there because I was tired of waiting for the STM32 to initialize a SSH session doing software crypto.

Overkill? Probably. But I had the free FPGA space, so why not?

azonenberg, 1 day ago

More progress: TX FIFO and status register are now on APB, leaving the Ethernet RX FIFO as the last remaining block on the legacy bus.

Very close to being ready to nuke it entirely, at which point I can start working on the memory mapping - the ultimate goal of this refactoring.

azonenberg, 10 hours ago

RX FIFO is now converted to APB, and I found and removed one of two unnecessary CDCs in the process (the other will be more work and I'll keep for a while).

Now chasing an apparently-harmless bug in which I get a zero-byte packet (start/commit pair with no data) before an actual frame. But I don't like it and want it fixed.

azonenberg, 9 hours ago

And fixed it, bad handling of inter-frame gaps.

So, here we are like a week later and I think I've shaved every last yak between me and memory mapping the FPGA over QSPI!

Here goes nothing.

azonenberg, 6 hours ago (edited 6 hours ago)

Well, this was an adventure but I have the first couple of peripherals working in memory mapped mode!

Got bit by yet another STM32H7 silicon bug, it took me a whole 20-30 minutes of staring at my code (and fixing unrelated bugs) before I opened up the errata sheet and found the problem: memory mapped writes will return a bus fault unless DQS is enabled.

The workaround is simple: set the "use DQS" bit in the write configuration register, then if you're using a bus that doesn't actually need DQS (like I am), just don't set the alt mode on DQS to connect to the peripheral.

This works great... as long as you don't accidentally enable DQS on reads as well.

If you do that, you'll deadlock the AHB bus on the STM32. Which will completely freeze the processor (to the point that it's unresponsive over JTAG, since CoreSight uses the same AMBA fabric rather than a dedicated APB bus as is the case with a lot of higher end SoCs).

Now your micro is soft-bricked and the only way to recover it is to spam resets and JTAG halt requests at it, and hope to win the race by freezing the CPU before it gets to the first memory mapped read.

azonenberg, 5 hours ago

Anyway, more code refactoring needed to use memory mapped IO for more peripherals, plus I need to investigate why memory mapped writes to the Ethernet transmit buffer aren't working (should be an easy fix, i already suspect i know what's going on).

But the bus bridging is actually working! Cortex-M7 AXI -> STM32 internal AHB -> OCTOSPI peripheral -> LVCMOS33 quad SPI -> FPGA internal APB -> on-FPGA peripherals. Memory mapped end to end.