Difference between revisions of "PXI Services"

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= PXI Services =
 
= PXI Services =
 
The 'pxi' sysmodule contains the following services:
 
The 'pxi' sysmodule contains the following services:
*PxiFS0
+
*[[Filesystem services PXI|PxiFS0]]
*PxiFS1
+
*[[Filesystem services PXI|PxiFS1]]
*PxiFSB
+
*[[Filesystem services PXI|PxiFSB]]
*PxiFSR
+
*[[Filesystem services PXI|PxiFSR]]
 
*[[Process Manager Services PXI|PxiPM]]
 
*[[Process Manager Services PXI|PxiPM]]
 
*[[Application Manager Services PXI|pxi:am9]]
 
*[[Application Manager Services PXI|pxi:am9]]
*pxi:dev
+
*[[Gamecard Services PXI|pxi:dev]]
*pxi:mc
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*[[Development Services PXI|pxi:mc]]
 
*[[Process Services PXI|pxi:ps9]]
 
*[[Process Services PXI|pxi:ps9]]
  
Each of these services has up to 4 static IPC buffers of size 0x1000. When any of these service ports are sync:d, the IPC cmdbuf (TLS+0x80+) is sent over PXI to the ARM9.
+
Each of these services has up to 4 static IPC buffers of size 0x1000. When any of these service ports are sync:d, the IPC cmdbuf (TLS+0x80+) is sent over [[PXI_Registers|PXI]] to the ARM9.
  
 
Each PXI service can only have one session open for it at a time.
 
Each PXI service can only have one session open for it at a time.
 +
 +
= Protocol =
 +
The communication protocol for normal PXI commands is documented below. The size of cmd_buf is calculated from the cmd_hdr. With newer FIRM the total size for command header + buffer must be at most 0x40 words, otherwise Process9 will panic.
 +
 +
The PXI protocol is bidirectional - both processors can host a PXI service for a given pxi_id. In practice, Process9 hosts all but one of the services (pxi_11 is hosted by pxi-module instead). Each pxi_id corresponds to a PXI command-handler(called from threads) which handles the actual command processing. With newer FIRM the pxi_id must be in a certain range.
 +
 +
There's a dedicated Process9 thread for receiving data from PXI(in newer FIRM this is the main-thread), once it finishes receiving a request it copies the cmd_buf into a buffer for the corresponding pxi_id then signals an event so that the cmd-handler thread can process it. Once a cmd-handler thread finishes processing a command, the thread itself then sends the response over PXI. This means that multiple commands for different pxiIDs can be be handled at the same time, even when one cmd-handler completely hangs/etc for example.
 +
 +
Process9 will execute [[SVC|svcBreak]] when it receives a PXI command with a pxi_id where another command with that same pxi_id is still being processed by the command-handler(this won't happen with commands sent by the ARM11 PXI-module, since it waits for the command reply before sending another command request for that same pxi_id).
 +
 +
=PXI service "pxi_11"=
 +
{| class="wikitable" border="1"
 +
|-
 +
!  Command Header
 +
!  Description
 +
|-
 +
| 0x00010040
 +
| PublishToSubscriber - this exposes [[Services|"srv:" notifications]] to the Process9-side using [[SRV:PublishToSubscriber]] (with flags=1), to allow sending card-insert notifications etc. directly to ARM11.
 +
|}
 +
 +
==Request==
 +
A11->A9 (u32) pxi_id
 +
A11->A9 (u32) cmd_hdr
 +
A11->A9 (u32[]) cmd_buf
 +
 +
==Response==
 +
A9->A11 (u32) pxi_id
 +
A9->A11 (u32) cmd_hdr
 +
A9->A11 (u32[]) cmd_buf
 +
 +
==pxi_id==
 +
0 = pxi_mc
 +
1 = pxi_fs
 +
2 = pxi_fs
 +
3 = pxi_fs
 +
4 = pxi_fs
 +
5 = pxi_pm
 +
6 = pxi_dev
 +
7 = pxi_am
 +
8 = pxi_ps
 +
9 = pxi_11
 +
 +
[[Category:Services]]

Latest revision as of 12:27, 18 September 2024

PXI Services[edit]

The 'pxi' sysmodule contains the following services:

Each of these services has up to 4 static IPC buffers of size 0x1000. When any of these service ports are sync:d, the IPC cmdbuf (TLS+0x80+) is sent over PXI to the ARM9.

Each PXI service can only have one session open for it at a time.

Protocol[edit]

The communication protocol for normal PXI commands is documented below. The size of cmd_buf is calculated from the cmd_hdr. With newer FIRM the total size for command header + buffer must be at most 0x40 words, otherwise Process9 will panic.

The PXI protocol is bidirectional - both processors can host a PXI service for a given pxi_id. In practice, Process9 hosts all but one of the services (pxi_11 is hosted by pxi-module instead). Each pxi_id corresponds to a PXI command-handler(called from threads) which handles the actual command processing. With newer FIRM the pxi_id must be in a certain range.

There's a dedicated Process9 thread for receiving data from PXI(in newer FIRM this is the main-thread), once it finishes receiving a request it copies the cmd_buf into a buffer for the corresponding pxi_id then signals an event so that the cmd-handler thread can process it. Once a cmd-handler thread finishes processing a command, the thread itself then sends the response over PXI. This means that multiple commands for different pxiIDs can be be handled at the same time, even when one cmd-handler completely hangs/etc for example.

Process9 will execute svcBreak when it receives a PXI command with a pxi_id where another command with that same pxi_id is still being processed by the command-handler(this won't happen with commands sent by the ARM11 PXI-module, since it waits for the command reply before sending another command request for that same pxi_id).

PXI service "pxi_11"[edit]

Command Header Description
0x00010040 PublishToSubscriber - this exposes "srv:" notifications to the Process9-side using SRV:PublishToSubscriber (with flags=1), to allow sending card-insert notifications etc. directly to ARM11.

Request[edit]

A11->A9 (u32) pxi_id
A11->A9 (u32) cmd_hdr
A11->A9 (u32[]) cmd_buf

Response[edit]

A9->A11 (u32) pxi_id
A9->A11 (u32) cmd_hdr
A9->A11 (u32[]) cmd_buf

pxi_id[edit]

0 = pxi_mc
1 = pxi_fs
2 = pxi_fs
3 = pxi_fs
4 = pxi_fs
5 = pxi_pm
6 = pxi_dev
7 = pxi_am
8 = pxi_ps
9 = pxi_11