Changes

1,627 bytes added ,  21:18, 12 December 2015
move protocol stuff to PXI Services since it is a FIRM construct
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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.
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= Protocol =
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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.
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Each pxi_id corresponds to a Process9 PXI [[PXI_Services|command-handler]](called from threads) which handles the actual command processing. With newer FIRM the pxi_id must be in a certain range.
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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.
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Process9 will execute [[SVC|svcBreak]] when it receives a PXI command with a pxi_id where another cmmand 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).
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==Request==
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A11->A9 (u32) pxi_id
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A11->A9 (u32) cmd_hdr
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A11->A9 (u32[]) cmd_buf
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==Response==
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A9->A11 (u32) pxi_id
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A9->A11 (u32) cmd_hdr
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A9->A11 (u32[]) cmd_buf
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==pxi_id==
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0 = pxi_mc
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1 = pxi_fs
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2 = pxi_fs
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3 = pxi_fs
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4 = pxi_fs
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5 = pxi_pm
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6 = pxi_dev
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7 = pxi_am
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8 = pxi_ps
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9 = stubbed
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