Difference between revisions of "IPC"
| Line 53: | Line 53: | ||
{| class="wikitable" border="1" | {| class="wikitable" border="1" | ||
|- | |- | ||
| − | ! | + | ! Type |
| + | ! scope="col" width="150" | Usual form | ||
! Description | ! Description | ||
|- | |- | ||
| + | | 0 | ||
| 0x00000000 | | 0x00000000 | ||
| − | | The corresponding value is a KHandle, that should be closed in calling process | + | <handle> |
| + | | The corresponding value is a KHandle, that should be closed in calling process. | ||
|- | |- | ||
| + | | 0 | ||
| 0x00000010 | | 0x00000010 | ||
| − | | The corresponding value is a KHandle, that will be duplicated | + | <handle> |
| + | | The corresponding value is a KHandle, that will be duplicated. | ||
|- | |- | ||
| + | | 0 | ||
| 0x00000020 | | 0x00000020 | ||
| − | | Let kernel set value to calling process ProcessID | + | <placeholder> |
| + | | Let kernel set value to calling process ProcessID. | ||
|- | |- | ||
| + | | 1 | ||
| 0x0000???2 <nowiki>|</nowiki> (size<<14) | | 0x0000???2 <nowiki>|</nowiki> (size<<14) | ||
| + | <ptr> | ||
| The corresponding value contains a ptr to a buffer of said size, that should be copied to an already set-up buffer in destination process at threadlocalstorage+0x180. | | The corresponding value contains a ptr to a buffer of said size, that should be copied to an already set-up buffer in destination process at threadlocalstorage+0x180. | ||
|- | |- | ||
| − | | | + | | 2 |
| − | | | + | | 0x00000004 |
| − | + | | Does something weird. | |
|- | |- | ||
| + | | 3 | ||
| + | | 0x00000006 | ||
| + | | Does nothing? | ||
| + | |- | ||
| + | | 4 | ||
| + | | 0x00000008 | ||
| + | | This command will cause a kernelpanic. | ||
| + | |- | ||
| + | | 5 | ||
| + | | <nowiki>0x0000000A | (size<<4)</nowiki> | ||
| + | <ptr> | ||
| + | | The corresponding value contains a ptr to a buffer of said size. | ||
| + | |- | ||
| + | | 6 | ||
| 0x0000000C <nowiki>|</nowiki> (size<<4) | | 0x0000000C <nowiki>|</nowiki> (size<<4) | ||
| − | | The corresponding value contains a ptr to a | + | <ptr> |
| − | + | | The corresponding value contains a ptr to a buffer of said size. | |
| + | |- | ||
| + | | 7 | ||
| + | | 0x0000000E <nowiki>|</nowiki> (size<<4) | ||
| + | <ptr> | ||
| + | | The corresponding value contains a ptr to a buffer of said size. | ||
|} | |} | ||
| + | |||
| + | Buffers from commands 5,6,7 will get mapped at virtual address 0x04000000+ in destination process. | ||
Revision as of 00:49, 4 August 2014
Every IPC command sent to services starts with a u32 header code:
| Bits | Description |
|---|---|
| 0-5 | Number of translate parameters (=x) |
| 6-11 | Number of normal parameters (=y) |
| 12-15 | Unused |
| 16-31 | Command ID |
The entire command has the following structure:
| Word | Size | Description |
|---|---|---|
| 0 | 1 | Header code |
| 1 | x | Normal parameters |
| x | y | Translate parameters |
Translate parameters are modified/translated transparently by the kernel. They are used to transfer handles/buffers between the different processes.
The type of parameter is described by the bits 1-3 in the translation descriptor. Parameter types accepted for sending by the kernel are: 0, 1, 2, 5, 6, 7. Type 0 is used to send handles across processes:
if desc & 0x30 == 0x20:
write process id to value
else:
translate handle
if desc & 0x30 == 0x10:
close handle for caller
For replies, only 0, 1, 5, 6, 7 are allowed. In other words any type 2 fields must be zeroed before calling svcReplyAndReceive on the server-side. For replies type 0, 1, 2 are ignored. Types 5, 6, 7 do something with the mem pointer upon reply. The type 0 descriptor can be used to ignore parameters. The number of parameters covered by a type-0 descriptor is (desc >> 26) + 1.
| Type | Usual form | Description |
|---|---|---|
| 0 | 0x00000000
<handle> |
The corresponding value is a KHandle, that should be closed in calling process. |
| 0 | 0x00000010
<handle> |
The corresponding value is a KHandle, that will be duplicated. |
| 0 | 0x00000020
<placeholder> |
Let kernel set value to calling process ProcessID. |
| 1 | 0x0000???2 | (size<<14)
<ptr> |
The corresponding value contains a ptr to a buffer of said size, that should be copied to an already set-up buffer in destination process at threadlocalstorage+0x180. |
| 2 | 0x00000004 | Does something weird. |
| 3 | 0x00000006 | Does nothing? |
| 4 | 0x00000008 | This command will cause a kernelpanic. |
| 5 | 0x0000000A | (size<<4)
<ptr> |
The corresponding value contains a ptr to a buffer of said size. |
| 6 | 0x0000000C | (size<<4)
<ptr> |
The corresponding value contains a ptr to a buffer of said size. |
| 7 | 0x0000000E | (size<<4)
<ptr> |
The corresponding value contains a ptr to a buffer of said size. |
Buffers from commands 5,6,7 will get mapped at virtual address 0x04000000+ in destination process.