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Artemis Milestone 2g (partial): bulk endpoint discovery + 2e disconnect teardown

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Picked up from a crashed session: xhci_driver.h/xhci.h already had the
bulk_in/out_ep_addr/max_packet fields and Endpoint-descriptor offset
macros scaffolded, but the actual walk that populates them was never
written. Added it: after 2f confirms a Mass Storage/SCSI/BOT interface,
a nested walk continues through the Endpoint descriptors that follow it
(bDescriptorType==5, stopping at the next Interface descriptor or end
of stream), keeping only Bulk-type endpoints and splitting IN/OUT by
bEndpointAddress bit 7. Also reset the four new fields in
xhci_bringup(), which the scaffolding had missed.

Also completed 2e's disconnect teardown, which was fully implemented
this session (not scaffolded): a Disable Slot command is now submitted
on a real disconnect, with the port's tracked slot ID captured and
cleared from port_slot_id[] immediately (before the command completes)
so a fresh connect on the same port isn't confused for one already in
progress, and DCBAA[slot_id] cleared only on a successful completion.

Verified live via QMP hotplug (deliberate device_add/device_del against
freshly launched, individually-tracked instances -- not whatever
happened to be attached at boot), all three architectures,
byte-identical: bulk IN endpoint=0x81, bulk OUT endpoint=0x02, then a
clean disconnect -> disable slot succeeded, no wedge. Caught and fixed
a documentation near-miss in the same pass: an initial draft cited the
probe-free three-arch acceptance boots as this feature's verification
evidence, but a stale leftover log directory from a pre-crash orphaned
QEMU process had been picked up by an `ls -dt | head -1` glob during
monitoring and mistaken for this session's own result -- the real
acceptance logs never had a device attached at all. Re-verified against
real PIDs and real log paths before writing FABRIC-2.md's final
writeup.

FABRIC-2.md Section X Milestone 2 updated: 2e's disconnect-teardown
checklist item marked done, 2g's endpoint-identification item marked
partially done (identification only -- Configure Endpoint / EP Context
wiring is still open).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R4VMX6VSKCten8nGgaMkq4
This commit is contained in:
Robert Allan James
2026-08-25 08:17:50 -04:00
co-authored by Claude Sonnet 5
parent b4bbd043d0
commit 96d55fcd87
15 changed files with 54535 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/starkernel/usb/xhci.c
+88 -5
View File
@@ -126,6 +126,7 @@ static xhci_dev_t *g_xhci_dev = NULL;
* (see the "Command Ring submission" section) so it can stay close to
* xhci_poll_events(), the read side of the same ring pair. */
int xhci_cmd_enable_slot(xhci_dev_t *dev);
int xhci_cmd_disable_slot(xhci_dev_t *dev, uint32_t slot_id);
int xhci_cmd_address_device(xhci_dev_t *dev, uint32_t slot_id,
uint32_t port_id, uint32_t speed);
int xhci_ep0_get_device_descriptor(xhci_dev_t *dev, uint32_t slot_id);
@@ -285,6 +286,7 @@ int xhci_bringup(xhci_dev_t *dev)
dev->pending_connect_speed = 0;
dev->connect_state = XHCI_CONN_IDLE;
dev->pending_connect_slot_id = 0;
dev->pending_disable_slot_id = 0;
dev->input_ctx = NULL;
dev->device_ctx = NULL;
dev->ep0_ring = NULL;
@@ -293,6 +295,10 @@ int xhci_bringup(xhci_dev_t *dev)
dev->pending_transfer_slot_id = 0;
dev->transfer_purpose = XHCI_XFER_NONE;
dev->config_total_length = 0;
dev->bulk_in_ep_addr = 0;
dev->bulk_in_max_packet = 0;
dev->bulk_out_ep_addr = 0;
dev->bulk_out_max_packet = 0;
dev->next_action = XHCI_NEXT_ACTION_NONE;
dev->next_action_slot_id = 0;
dev->next_action_length = 0;
@@ -358,6 +364,16 @@ int xhci_cmd_enable_slot(xhci_dev_t *dev)
return 0;
}
int xhci_cmd_disable_slot(xhci_dev_t *dev, uint32_t slot_id)
{
if (!dev || !dev->cmd_ring) return -1;
/* Slot ID goes in control[31:24], same field Address Device uses --
* no parameter/status payload needed, this command just names a slot. */
xhci_submit_command(dev, 0, 0, XHCI_TRB_TYPE_DISABLE_SLOT_CMD, slot_id << 24);
console_println("xhci: disable slot command submitted");
return 0;
}
/* Default EP0 Max Packet Size by PORTSC.Port Speed, used before any device
* descriptor has been read (xHCI 1.2 spec's own recommended defaults --
* the real value comes from bMaxPacketSize0 once 2f reads the device
@@ -697,12 +713,27 @@ void xhci_poll_events(void)
console_println("xhci: port status change -- device disconnected");
if (port_id >= 1 && port_id <= XHCI_MAX_TRACKED_PORTS &&
dev->port_slot_id[port_id - 1] != 0) {
/* Real teardown (Disable Slot command, DCBAA entry
* clear, callback to Section U's code) is a later
* increment -- for now just stop tracking the slot
* so a future connect on this port isn't confused
* for one already in progress. */
uint32_t disconnecting_slot_id = dev->port_slot_id[port_id - 1];
/* Stop tracking the slot immediately so a future
* connect on this port isn't confused for one
* already in progress -- independent of whether
* the Disable Slot command below can be issued
* right now. */
dev->port_slot_id[port_id - 1] = 0;
if (dev->connect_state == XHCI_CONN_IDLE) {
dev->pending_disable_slot_id = disconnecting_slot_id;
dev->connect_state = XHCI_CONN_AWAIT_DISABLE_SLOT;
xhci_cmd_disable_slot(dev, disconnecting_slot_id);
} else {
/* Same single-outstanding-command limitation
* as Enable Slot above -- the slot's DCBAA
* entry is simply left stale (harmless: it is
* never looked at again since port_slot_id[]
* no longer references it, and a genuinely
* concurrent connect/disconnect pair isn't
* this driver's current scope). */
console_println("xhci: disable slot skipped -- command ring busy");
}
}
}
/* Acknowledge only CSC (RW1CS): preserve PP, write 0 for
@@ -758,6 +789,22 @@ void xhci_poll_events(void)
}
dev->connect_state = XHCI_CONN_IDLE;
dev->pending_connect_port_id = 0;
} else if (dev->connect_state == XHCI_CONN_AWAIT_DISABLE_SLOT) {
if (code == XHCI_COMPLETION_CODE_SUCCESS) {
/* DCBAA[slot_id] cleared on success only -- if the
* controller reports failure, leave it: the slot
* may still be in a state where zeroing its
* context pointer out from under the controller
* is unsafe, and port_slot_id[] no longer
* references this slot either way, so nothing
* else in this driver will look at it again. */
((uint64_t *)dev->dcbaa)[dev->pending_disable_slot_id] = 0;
console_println("xhci: disable slot succeeded");
} else {
console_println("xhci: disable slot failed");
}
dev->connect_state = XHCI_CONN_IDLE;
dev->pending_disable_slot_id = 0;
} else {
console_println("xhci: command completion event");
}
@@ -844,6 +891,42 @@ void xhci_poll_events(void)
iface_subclass == USB_SUBCLASS_SCSI &&
iface_protocol == USB_PROTOCOL_BOT) {
console_println("xhci: confirmed Mass Storage / SCSI / BOT device");
/* Walk the Endpoint descriptors that
* follow this Interface descriptor,
* stopping at the next Interface
* descriptor (start of a different
* interface's endpoints) or end of
* the stream. Only bulk endpoints
* are of interest for BOT. */
uint16_t ep_off = (uint16_t)(off + desc_len);
while (ep_off + 2 <= len) {
uint8_t ep_desc_len = dev->config_descriptor[ep_off + USB_DESC_OFF_LENGTH];
uint8_t ep_desc_type = dev->config_descriptor[ep_off + USB_DESC_OFF_TYPE];
if (ep_desc_len == 0) break; /* malformed -- avoid an infinite loop */
if (ep_desc_type == USB_DESC_TYPE_INTERFACE) break;
if (ep_desc_type == USB_DESC_TYPE_ENDPOINT &&
ep_off + USB_EP_OFF_MAX_PACKET_SIZE + 1 < len) {
uint8_t ep_addr = dev->config_descriptor[ep_off + USB_EP_OFF_ADDRESS];
uint8_t ep_attr = dev->config_descriptor[ep_off + USB_EP_OFF_ATTRIBUTES];
uint16_t ep_max_packet = (uint16_t)(dev->config_descriptor[ep_off + USB_EP_OFF_MAX_PACKET_SIZE] |
((uint16_t)dev->config_descriptor[ep_off + USB_EP_OFF_MAX_PACKET_SIZE + 1] << 8));
if ((ep_attr & USB_EP_ATTR_TYPE_MASK) == USB_EP_TYPE_BULK) {
if (ep_addr & USB_EP_ADDR_DIR_MASK) {
dev->bulk_in_ep_addr = ep_addr;
dev->bulk_in_max_packet = ep_max_packet;
xhci_log_hex32("xhci: bulk IN endpoint=", ep_addr);
} else {
dev->bulk_out_ep_addr = ep_addr;
dev->bulk_out_max_packet = ep_max_packet;
xhci_log_hex32("xhci: bulk OUT endpoint=", ep_addr);
}
}
}
ep_off = (uint16_t)(ep_off + ep_desc_len);
}
if (dev->bulk_in_ep_addr == 0 || dev->bulk_out_ep_addr == 0) {
console_println("xhci: warning -- BOT device missing a bulk IN or OUT endpoint");
}
/* Deferred (see xhci_dev_t's
* next_action doc comment) rather
* than called directly here --