Difference between revisions of "Thread Local Storage"
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(Created page with "Each thread is given a 0x200-byte thread-local-storage block by the kernel. It is used during IPC communications. {| class="wikitable" border="1" |- ! ...") |
(Couldn't find this info anywhere. If it was already somewhere else, at least it's discoverable now :p) |
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| − | Each thread is given a 0x200-byte thread-local-storage block by the kernel. It is used during [[IPC_Command_Structure|IPC communications]]. | + | Each thread is given a 0x200-byte thread-local-storage block by the kernel. It is used during [[IPC_Command_Structure|IPC communications]]. Each [[KProcess]] has a linked list of [[KThreadLocalPage]] objects and each object has a pointer to a page(0x1000 bytes) of FCRAM, which is used for up to 8 thread-local-storage blocks. The [[KThreadLocalPage]] is used to track which thread-local-storage blocks are used so it can allocate new ones as new threads are created. |
| + | A pointer to the thread-local-storage can be read using the ARM instruction: | ||
| + | mrc 15, 0, rX, cr13, cr0, 3 | ||
| + | |||
| + | Every application has RW access to its thread-local-storage. | ||
| + | |||
| + | The kernel requires the application to put IPC parameters and IPC static buffers inside the thread-local-storage: | ||
{| class="wikitable" border="1" | {| class="wikitable" border="1" | ||
|- | |- | ||
| Line 17: | Line 23: | ||
| 0x180 | | 0x180 | ||
| 0x80 | | 0x80 | ||
| − | | IPC static buffers | + | | IPC static buffers: 16 pairs of a [[IPC|static buffer translation descriptor]] (specifying the buffer size) and a buffer pointer |
|} | |} | ||
Latest revision as of 15:13, 20 March 2016
Each thread is given a 0x200-byte thread-local-storage block by the kernel. It is used during IPC communications. Each KProcess has a linked list of KThreadLocalPage objects and each object has a pointer to a page(0x1000 bytes) of FCRAM, which is used for up to 8 thread-local-storage blocks. The KThreadLocalPage is used to track which thread-local-storage blocks are used so it can allocate new ones as new threads are created.
A pointer to the thread-local-storage can be read using the ARM instruction:
mrc 15, 0, rX, cr13, cr0, 3
Every application has RW access to its thread-local-storage.
The kernel requires the application to put IPC parameters and IPC static buffers inside the thread-local-storage:
| Offset | Size | Description |
|---|---|---|
| 0 | 0x80 | Undefined, can be used by application for any purpose. |
| 0x80 | 0x100 | IPC command with parameters |
| 0x180 | 0x80 | IPC static buffers: 16 pairs of a static buffer translation descriptor (specifying the buffer size) and a buffer pointer |