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Diffstat (limited to 'nuttx/Documentation/NuttxPortingGuide.html')
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1 files changed, 245 insertions, 14 deletions
diff --git a/nuttx/Documentation/NuttxPortingGuide.html b/nuttx/Documentation/NuttxPortingGuide.html index 5361a2866..526892d3e 100644 --- a/nuttx/Documentation/NuttxPortingGuide.html +++ b/nuttx/Documentation/NuttxPortingGuide.html @@ -12,7 +12,7 @@ <h1><big><font color="#3c34ec"> <i>NuttX RTOS Porting Guide</i> </font></big></h1> - <p>Last Updated: December 17, 2012</p> + <p>Last Updated: December 18, 2012</p> </td> </tr> </table> @@ -92,7 +92,8 @@ <a href="#upenableirq">4.1.17 <code>up_enable_irq()</code></a><br> <a href="#upprioritizeirq">4.1.18 <code>up_prioritize_irq()</code></a></br> <a href="#upputc">4.1.19 <code>up_putc()</code></a></br> - <a href="#systemtime">4.1.20 System Time and Clock</a> + <a href="#systemtime">4.1.20 System Time and Clock</a><br> + <a href="#addrenv">4.1.21 Address Environments</a> </ul> <a href="#exports">4.2 APIs Exported by NuttX to Architecture-Specific Logic</a> <ul> @@ -1622,7 +1623,7 @@ The system can be re-made subsequently by just typing <code>make</code>. is defined. </p> -<p><b>Inputs</b>:</p> +<p><b>Input Parameters</b>:</p> <ul> <li> <code>tcb</code>: The TCB of new task. @@ -1658,7 +1659,7 @@ The system can be re-made subsequently by just typing <code>make</code>. is defined. </p> -<p><b>Inputs:</b></p> +<p><b>Input Parameters:</b></p> <ul> <li> <code>tcb</code>: The TCB of new task. @@ -1694,7 +1695,7 @@ The system can be re-made subsequently by just typing <code>make</code>. function is called. </p> -<p><b>Inputs</b>: +<p><b>Input Parameters</b>: <ul> <li><code>tcb</code>: Refers to the tcb to be unblocked. This tcb is in one of the waiting tasks lists. It must be moved to @@ -1715,7 +1716,7 @@ The system can be re-made subsequently by just typing <code>make</code>. logic. Interrupts will always be disabled when this function is called. -<p><b>Inputs:</b></p> +<p><b>Input Parameters:</b></p> <ul> <li><code>tcb</code>: Refers to a task in the ready-to-run list (normally the task at the head of the list). It most be @@ -1771,7 +1772,7 @@ The system can be re-made subsequently by just typing <code>make</code>. function is called. </p> -<p><b>Inputs:</b></p> +<p><b>Input Parameters:</b></p> <ul> <li> <code>tcb</code>: The TCB of the task that has been reprioritized @@ -2110,6 +2111,236 @@ else To retrieve that variable use: </p> +<h3><a name="addrenv">4.1.21 Address Environments</a></h3> + +<p> + CPUs that support memory management units (MMUs) may provide <i>address environments</i> within which tasks and their child threads execute. + The configuration indicates the CPUs ability to support address environments by setting the configuration varabile <code>CONFIG_ADDRENV=y</code>. + These address environments are created only when tasks are created via <code>exec()</code> or <code>exec_module()</code> (see <code>include/nuttx/binfmt/binfmt.h</code>). +</p> +<p> + When <code>CONFIG_ADDRENV=y</code> is set in the board configuration, the CPU-specific logic must provide a set of interfaces as defined in the header file <code>include/nuttx/arch.h</code>. + These interfaces are listed below and described in detail in the following paragraphs. +</p> +<p> + The CPU-specific logic must provide two categories in interfaces: +</p> +<ol> + <li> + <p> + <b>Binary Loader Support</b>. + These are low-level interfaces used in <code>binfmt/</code> to instantiate tasks with address environments. + These interfaces all operate on type <code>task_addrenv_t</code> which is an abstract representation of a asks's address environment and must be defined in arch/arch.h if <code>CONFIG_ADDRENVM</code> is defined. + These low-level interfaces include: + </p> + <ul> + <li> + <a href="#up_addrenv_create">4.1.21.1 <code>up_addrenv_create()</code></a>: + Create an address environment. + </li> + <li> + <a href="#up_addrenv_vaddr">4.1.21.2 <code>up_addrenv_vaddr()</code></a>: + Returns the virtual base address of the address environment. + </li> + <li> + <a href="#up_addrenv_select">4.1.21.3 <code>up_addrenv_select()</code></a>: + Instantiate an address environment. + </li> + <li> + <a href="#up_addrenv_restore">4.1.21.4 <code>up_addrenv_restore()</code></a>: + Restore an address environment. + </li> + <li> + <a href="#up_addrenv_destroy">4.1.21.5 <code>up_addrenv_destroy()</code></a>: + Destroy an address environment. + </li> + <li> + <a href="#up_addrenv_assign">4.1.21.6 <code>up_addrenv_assign()</code></a>: + Assign an address environment to a TCB. + </li> + </ul> + </li> + <li> + <p> + <b>Tasking Support</b>. + Other interfaces must be provided to support higher-level interfaces used by the NuttX tasking logic. + These interfaces are* used by the functions in <code>sched/</code> and all operate on the TCB which as been assigned an address environment by <code>up_addrenv_assign()</code>. + </p> + <ul> + <li> + <a href="#up_addrenv_share">4.1.21.7 <code>up_addrenv_share()</code></a>: + Clone the address environment assigned to one TCB to another. + This operation is done when a pthread is created that share's the same address environment. + </li> + <li> + <a href="#up_addrenv_release">4.1.21.8 <code>up_addrenv_release()</code></a>: + ARelease the TCBs reference to an address environment when a task/thread exits. + </li> + </ul> + </li> +</ol> + + +<h4><a name="up_addrenv_create">4.1.21.1 <code>up_addrenv_create()</code></a></h4> +<p><b>Prototype</b>:</p> +<ul> + <code>int up_addrenv_create(size_t envsize, FAR task_addrenv_t *addrenv);</code> +</ul> +<p><b>Description</b>:</p> +<ul> + This function is called from the binary loader logic when a new task is created in order to instantiate an address environment for the task. + <code>up_addrenv_create()</code> is essentially the allocator of the physical memory for the new task. +</ul> +<p><b>Input Parameters</b>:</p> +<ul> + <li><code>envsize</code>: The size (in bytes) of the address environment needed by the task.</li> + <li><code>addrenv</code>: The location to return the representation of the task address environment.</li> +</ul> +<p><b>Returned Value</b>:</p> +<ul> + Zero (<code>OK</code>) on success; a negated <code>errno</code> value on failure. +</ul> + +<h4><a name="up_addrenv_vaddr">4.1.21.2 <code>up_addrenv_vaddr()</code></a></h4> +<p><b>Prototype</b>:<p> +<ul> + <code>int up_addrenv_vaddr(FAR task_addrenv_t addrenv, FAR void **vaddr);</code> +</ul> +<p><b>Description</b>:</p> +<ul> + Return the virtual address associated with the newly create address environment. + This function is used by the binary loaders in order get an address that can be used to initialize the new task. +</ul> +<p><b>Input Parameters</b>:</p> +<ul> + <li><code>addrenv</code>: The representation of the task address environment previously returned by up_addrenv_create.</li> + <li><code>vaddr</code>: The location to return the virtual address.</li> +</ul> +<p><b>Returned Value</b>:</p> +<ul> + Zero (<code>OK</code>) on success; a negated <code>errno</code> value on failure. +</ul> + +<h4><a name="up_addrenv_select">4.1.21.3 <code>up_addrenv_select()</code></a></h4> +<p><b>Prototype</b>:<p> +<ul> + <code>int up_addrenv_select(task_addrenv_t addrenv, hw_addrenv_t *oldenv);</code> +</ul> +<p><b>Description</b>:</p> +<ul> + After an address environment has been established for a task (via <code>up_addrenv_create())</code>, this function may be called to to instantiate that address environment in the virtual address space. + This might be necessary, for example, to load the code for the task from a file or to access address environment private data. +</ul> +<p><b>Input Parameters</b>:</p> +<ul> + <li><code>addrenv</code>: The representation of the task address environment previously returned by up_addrenv_create.</li> + <li><code>oldenv</code>: + The address environment that was in place before <code>up_addrenv_select()</code> was called. + This may be used with <code>up_addrenv_restore()</code> to restore the original address environment that was in place before <code>up_addrenv_select()</code> was called. + Note that this may be a task agnostic, hardware representation that is different from <code>task_addrenv_t</code>. + </li> +</ul> +<p><b>Returned Value</b>:</p> +<ul> + Zero (<code>OK</code>) on success; a negated <code>errno</code> value on failure. +</ul> + +<h4><a name="up_addrenv_restore">4.1.21.4 <code>up_addrenv_restore()</code></a></h4> +<p><b>Prototype</b>:<p> +<ul> + <code>int up_addrenv_restore(hw_addrenv_t oldenv);</code> +</ul> +<p><b>Description</b>:</p> +<ul> + After an address environment has been temporarilty instantiated by <code>up_addrenv_select</code>, + this function may be called to to restore the original address environment. +</ul> +<p><b>Input Parameters</b>:</p> +<ul> + <li><code>oldenv</code>: The hardware representation of the address environment previously returned by <code>up_addrenv_select()</code>.</li> +</ul> +<p><b>Returned Value</b>:</p> +<ul> + Zero (<code>OK</code>) on success; a negated <code>errno</code> value on failure. +</ul> + +<h4><a name="up_addrenv_destroy">4.1.21.5 <code>up_addrenv_destroy()</code></a></h4> +<p><b>Prototype</b>:<p> +<ul> + <code>int up_addrenv_destroy(task_addrenv_t addrenv);</code> +</ul> +<p><b>Description</b>:</p> +<ul> + Called from the binary loader loader during error handling to destroy the address environment previously created by <code>up_addrenv_create()</code>. +</ul> +<p><b>Input Parameters</b>:</p> +<ul> + <li><code>addrenv</code>: The representation of the task address environment previously returned by up_addrenv_create.</li> +</ul> +<p><b>Returned Value</b>:</p> +<ul> + Zero (<code>OK</code>) on success; a negated <code>errno</code> value on failure. +</ul> + +<h4><a name="up_addrenv_assign">4.1.21.6 <code>up_addrenv_assign()</code></a></h4> +<p><b>Prototype</b>:<p> +<ul> + <code>int up_addrenv_assign(task_addrenv_t addrenv, FAR _TCB *tcb);</code> +</ul> +<p><b>Description</b>:</p> +<ul> + Assign an address environment to a TCB. +</ul> +<p><b>Input Parameters</b>:</p> +<ul> + <li><code>addrenv</code>: The representation of the task address environment previously returned by up_addrenv_create.</li> + <li><code>tcb</code>: The TCB of the task to receive the address environment.</li> +</ul> +<p><b>Returned Value</b>:</p> +<ul> + Zero (<code>OK</code>) on success; a negated <code>errno</code> value on failure. +</ul> + +<h4><a name="up_addrenv_share">4.1.21.7 <code>up_addrenv_share()</code></a></h4> +<p><b>Prototype</b>:<p> +<ul> + <code>int up_addrenv_share(FAR const _TCB *ptcb, FAR _TCB *ctcb);</code> +</ul> +<p><b>Description</b>:</p> +<ul> + This function is called from the core scheduler logic when a thread is created that needs to share the address ennvironment of its parent task. + In this case, the parent's address environment needs to be "cloned" for the child thread. +</ul> +<p><b>Input Parameters</b>:</p> +<ul> + <li><code>ptcb</code>: The TCB of the parent task that has the address environment.</li> + <li><code>ctcb</code>: The TCB of the child thread needing the address environment.</li> +</ul> +<p><b>Returned Value</b>:</p> +<ul> + Zero (<code>OK</code>) on success; a negated <code>errno</code> value on failure. +</ul> + +<h4><a name="up_addrenv_release">4.1.21.8 <code>up_addrenv_release()</code></a></h4> +<p><b>Prototype</b>:<p> +<ul> + <code>int up_addrenv_release(FAR _TCB *tcb);</code> +</ul> +<p><b>Description</b>:</p> +<ul> + This function is called when a task or thread exits in order to release its reference to an address environment. + When there are no furtherreferences to an address environment, that address environment should + be destroyed. +</ul> +<p><b>Input Parameters</b>:</p> +<ul> + <li><code>tcb</code>: The TCB of the task or thread whose the address environment will be released.</li> +</ul> +<p><b>Returned Value</b>:</p> +<ul> + Zero (<code>OK</code>) on success; a negated <code>errno</code> value on failure. +</ul> + <h2><a name="exports">4.2 APIs Exported by NuttX to Architecture-Specific Logic</a></h2> <p> These are standard interfaces that are exported by the OS @@ -3470,7 +3701,7 @@ extern void up_ledoff(int led); All PM interfaces are declared in the file <code>include/nuttx/power/pm.h</code>. </p> -<h4><a name="pminitialize">6.4.2.1 pm_initialize()</a></h4> +<h4><a name="pminitialize">6.4.2.1 <code>pm_initialize()</code></a></h4> <p><b>Function Prototype:</b></p> <ul><pre> #include <nuttx/power/pm.h> @@ -3487,7 +3718,7 @@ None None </p> -<h4><a name="pmregister">6.4.2.2 pm_register()</a></h4> +<h4><a name="pmregister">6.4.2.2 <code>pm_register()</code></a></h4> <p><b>Function Prototype:</b></p> <ul><pre> #include <nuttx/power/pm.h> @@ -3507,7 +3738,7 @@ int pm_register(FAR struct pm_callback_s *callbacks); Zero (<code>OK</code>) on success; otherwise a negater <code>errno</code> value is returned. </p> -<h4><a name="pmactivity">6.4.2.3 pm_activity()</a></h4> +<h4><a name="pmactivity">6.4.2.3 <code>pm_activity()</code></a></h4> <p><b>Function Prototype:</b></p> <ul><pre> #include <nuttx/power/pm.h> @@ -3534,7 +3765,7 @@ void pm_activity(int priority); This function may be called from an interrupt handler (this is the ONLY PM function that may be called from an interrupt handler!). </p> -<h4><a name="pmcheckstate">6.4.2.4 pm_checkstate()</a></h4> +<h4><a name="pmcheckstate">6.4.2.4 <code>pm_checkstate()</code></a></h4> <p><b>Function Prototype:</b></p> <ul><pre> #include <nuttx/power/pm.h> @@ -3561,7 +3792,7 @@ enum pm_state_e pm_checkstate(void); The recommended power management state. </p> -<h4><a name="pmchangestate">6.4.2.5 pm_changestate()</a></h4> +<h4><a name="pmchangestate">6.4.2.5 <code>pm_changestate()</code></a></h4> <p><b>Function Prototype:</b></p> <ul><pre> #include <nuttx/power/pm.h> @@ -3596,7 +3827,7 @@ enum pm_state_e pm_checkstate(void); These callback functions can be used to provide power management information to the driver. </p> -<h4><a name="pmprepare">6.4.3.1 prepare()</a></h4> +<h4><a name="pmprepare">6.4.3.1 <code>prepare()</code></a></h4> <p><b>Function Prototype:</b></p> <ul><pre> int (*prepare)(FAR struct pm_callback_s *cb, enum pm_state_e pmstate); @@ -3624,7 +3855,7 @@ int (*prepare)(FAR struct pm_callback_s *cb, enum pm_state_e pmstate); consumption modes! </p> -<h4><a name="pmnotify">6.4.3.1 notify()</a></h4> +<h4><a name="pmnotify">6.4.3.1 <code>notify()</code></a></h4> <p><b>Function Prototype:</b></p> <ul><pre> #include <nuttx/power/pm.h> |