Difference between revisions of "Sm modules"

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== main_loop ==
 
== main_loop ==
  
This uses syscall 4 (RegisterIrqHandler) to register a common handler for incoming commands. Then it loops while sm is "active". Then it sets handler for commands = null pointer.
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This uses syscall 4 (RegisterIrqHandler) to register a common handler for incoming commands (cmd_handler). Then it loops while sm is "active". Then it sets handler for commands = null pointer.
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== cmd_handler ==
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This is the common handler for all incoming commands. It reads paddr from 0xE0000014 and ANDs it with 1 to check validity. It checks that size is valid (>= 0x40 and < 0x1000), copies command buffer into private f00d memory and executes an appropriate command handler.

Revision as of 03:03, 7 March 2018

sm common code

sm modules are loaded to 0x80B000, then code from that addr is executed.

There is a lot of common code shared between sm: entry, cmd handler, cmd setup, etc

Entry

This is the first code executed in sm. It's located at 0x80B000. It does the following:

  • Get random value (stack cookie?)
  • call_ctors()
  • sm_main()
  • call_dtors()
  • syscall 1: Unload
  • while(1) sleep()

call_ctors/call_dtors

These just call function pointers, basically libc_init_array.

sm_main

It has a memory pool allocated on stack. It's filled with structures for command handlers. Then, it calls main_loop.

main_loop

This uses syscall 4 (RegisterIrqHandler) to register a common handler for incoming commands (cmd_handler). Then it loops while sm is "active". Then it sets handler for commands = null pointer.

cmd_handler

This is the common handler for all incoming commands. It reads paddr from 0xE0000014 and ANDs it with 1 to check validity. It checks that size is valid (>= 0x40 and < 0x1000), copies command buffer into private f00d memory and executes an appropriate command handler.