JIT services: Difference between revisions

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nnMain just initializes [[RO_services|ro:1]], then starts hosting the service from the main-thread with max_sessions=1 (threads are not created for service-hosting).

This is intended to only be used by Applications. The ~~initialization~~ in sdknso uses [[Applet_Manager_services#PrepareForJit|PrepareForJit]] at the start. sdknso ~~later~~ uses [[SVC|svcCreateCodeMemory]].

This is intended to only be used by Applications. The service-init in sdknso just uses [[Applet_Manager_services#PrepareForJit|PrepareForJit]] at the start, then gets the service.

sdknso CreateJitEnvironment implements the remaining initialization. After some validation, this uses [[SVC|svcCreateCodeMemory]] (can be called twice). Then [[#CreateJitEnvironment]] is used. TransferMemory with an user-specified buffer is created with permissions=None, which is then used with [[#LoadPlugin]]. When successful, this lastly uses [[#GetCodeAddress]].

This loads the user-specified [[NRO]] into sysmodule-context ("DllPlugin"), and calls various symbols from that NRO. It seems the code writing (in cmd GenerateCode) is done via symbol-calling, allowing the NRO to handle input_buffer->code translation+writing.

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{| class="wikitable" border="1"

|-

! Cmd || Name ~~|| Notes~~

! Cmd || Name

|-

| 0 || ~~CreateJitEnvironment || Returns an~~ [[#~~IJitEnvironment~~]]

| 0 || [[#CreateJitEnvironment]]

|-

|}

== CreateJitEnvironment ==

Takes two input u64s, 3 input handles, returns an [[#IJitEnvironment]].

= IJitEnvironment =

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! Cmd || Name

|-

| 0 || GenerateCode

| 0 || [[#GenerateCode]]

|-

| 1 || Control

| 1 || [[#Control]]

|-

| 1000 || LoadPlugin

| 1000 || [[#LoadPlugin]]

|-

| 1001 || GetCodeAddress

| 1001 || [[#GetCodeAddress]]

|}

== GenerateCode ==

Takes an u32, an u64, a [[#CodeRange]], a [[#CodeRange]], a [[#Struct32]], a type-0x5 input buffer, a type-0x6 output buffer, and returns an output s32, a [[#CodeRange]], a [[#CodeRange]].

== Control ==

Takes an input u64, a type-0x5 input buffer, a type-0x6 output buffer, and returns an output s32.

== LoadPlugin ==

Takes an input u64, a handle, two type-0x5 input buffers, no output.

== GetCodeAddress ==

No input, returns two output u64s which are loaded from state.

== CodeRange ==

This is "nn::jit::CodeRange". This is a 0x10-byte struct. This is 8-byte aligned.

== Struct32 ==

This is "nn::jitsrv::Struct32". This is a 0x20-byte struct. This is 8-byte aligned.

@@ Line 3: / Line 3: @@
 nnMain just initializes [[RO_services|ro:1]], then starts hosting the service from the main-thread with max_sessions=1 (threads are not created for service-hosting).
-This is intended to only be used by Applications. The initialization in sdknso uses [[Applet_Manager_services#PrepareForJit|PrepareForJit]] at the start. sdknso later uses [[SVC|svcCreateCodeMemory]].
+This is intended to only be used by Applications. The service-init in sdknso just uses [[Applet_Manager_services#PrepareForJit|PrepareForJit]] at the start, then gets the service.
+sdknso CreateJitEnvironment implements the remaining initialization. After some validation, this uses [[SVC|svcCreateCodeMemory]] (can be called twice). Then [[#CreateJitEnvironment]] is used. TransferMemory with an user-specified buffer is created with permissions=None, which is then used with [[#LoadPlugin]]. When successful, this lastly uses [[#GetCodeAddress]].
 This loads the user-specified [[NRO]] into sysmodule-context ("DllPlugin"), and calls various symbols from that NRO. It seems the code writing (in cmd GenerateCode) is done via symbol-calling, allowing the NRO to handle input_buffer->code translation+writing.
@@ Line 12: / Line 14: @@
 {| class="wikitable" border="1"
 |-
-! Cmd || Name || Notes
+! Cmd || Name
 |-
-| 0 || CreateJitEnvironment || Returns an [[#IJitEnvironment]]
+| 0 || [[#CreateJitEnvironment]]
 |-
 |}
+== CreateJitEnvironment ==
+Takes two input u64s, 3 input handles, returns an [[#IJitEnvironment]].
 = IJitEnvironment =
@@ Line 25: / Line 30: @@
 ! Cmd || Name
 |-
-| 0 || GenerateCode
+| 0 || [[#GenerateCode]]
 |-
-| 1 || Control
+| 1 || [[#Control]]
 |-
-| 1000 || LoadPlugin
+| 1000 || [[#LoadPlugin]]
 |-
-| 1001 || GetCodeAddress
+| 1001 || [[#GetCodeAddress]]
 |}
+== GenerateCode ==
+Takes an u32, an u64, a [[#CodeRange]], a [[#CodeRange]], a [[#Struct32]], a type-0x5 input buffer, a type-0x6 output buffer, and returns an output s32, a [[#CodeRange]], a [[#CodeRange]].
+== Control ==
+Takes an input u64, a type-0x5 input buffer, a type-0x6 output buffer, and returns an output s32.
+== LoadPlugin ==
+Takes an input u64, a handle, two type-0x5 input buffers, no output.
+== GetCodeAddress ==
+No input, returns two output u64s which are loaded from state.
+== CodeRange ==
+This is "nn::jit::CodeRange". This is a 0x10-byte struct. This is 8-byte aligned.
+== Struct32 ==
+This is "nn::jitsrv::Struct32". This is a 0x20-byte struct. This is 8-byte aligned.