IPC commands are written to the [[Thread Local Storage]] at offset 0x80 and submitted using [[SVC|svcSendSyncRequest]]. If the kernel was able to dispatch the request, the server reply will be written to TLS+0x80. Often the second word of the response data is the error code (or 0 if success). IPC commands and IPC replies follow the same structure.
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IPC requests are written to the [[Thread Local Storage]] at offset 0x80 and submitted using [[SVC|svcSendSyncRequest]]. If the kernel was able to dispatch the request, the server reply will be written to TLS+0x80 before svcSendSyncRequest returns. By convention, the second word of the response data is an error code (or 0 on success). IPC requests and IPC replies follow the same structure.
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Every IPC message starts with a u32 header code. Parameters, if any, are written following this header. There are "normal parameters", which are fixed-size words, and there are "translate parameters", which are of flexible size and each of which begins with a header. The entire command has the following structure:
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Every IPC message starts with a u32 header code. Parameters (if any) are written following this header. There are "normal parameters", which are fixed-size words, and there are "translate parameters", which are of flexible size and each of which begins with a header. The entire command has the following structure: