Add addrenv.h; First cut at Cortex-A address environment structures; Add configuration options to setup address enviornment

arch/Kconfig

@@ -154,7 +154,7 @@ config ARCH_HAVE_EXTCLK
 	bool
 	default n
 
-config ARCH_ADDRENV
+menuconfig ARCH_ADDRENV
 	bool "Address environments"
 	default n
 	depends on ARCH_HAVE_ADDRENV
@@ -162,6 +162,62 @@ config ARCH_ADDRENV
 		Support per-task address environments using the MMU... i.e., support
 		"processes"
 
+if ARCH_ADDRENV && ARCH_HAVE_MMU
+
+config ARCH_TEXT_VBASE
+	hex "Virtual .text base"
+	---help---
+		The virtual address of the beginning the .text region
+
+config ARCH_DATA_VBASE
+	hex "Virtual .bss/.data base"
+	---help---
+		The virtual address of the beginning of the .bss/.data region.
+
+config ARCH_HEAP_VBASE
+	hex "Virtual heap base"
+	---help---
+		The virtual address of the beginning of the heap region.
+
+config ARCH_STACK_VBASE
+	hex "Virtual stack base"
+	---help---
+		The virtual address of the beginning the stack region
+
+config ARCH_TEXT_NPAGES
+	int "Max .text pages"
+	default 1
+	---help---
+		The maximum number of pages that can allocated for the .text region.
+		This, along with knowledge of the page size, determines the size of
+		the .text virtual address space. Default is 1.
+
+config ARCH_DATA_NPAGES
+	int "Max .bss/.data pages"
+	default 1
+	---help---
+		The maximum number of pages that can allocated for the .bss/.data
+		region. This, along with knowledge of the page size, determines the
+		size of the .bss/.data virtual address space. Default is 1.
+
+config ARCH_HEAP_NPAGES
+	int "Max heap pages"
+	default 1
+	---help---
+		The maximum number of pages that can allocated for the heap region.
+		This, along with knowledge of the page size, determines the size of
+		the heap virtual address space. Default is 1.
+
+config ARCH_STACK_NPAGES
+	int "Max. stack pages"
+	default 1
+	---help---
+		The maximum number of pages that can allocated for the stack region.
+		This, along with knowledge of the page size, determines the size of
+		the stack virtual address space. Default is 1.
+
+endif # ARCH_ADDRENV && ARCH_HAVE_MMU
+
 menuconfig PAGING
 	bool "On-demand paging"
 	default n

arch/arm/include/arch.h

@@ -50,7 +50,7 @@
 #endif
 
 /****************************************************************************
- * Definitions
+ * Pre-processor Definitions
  ****************************************************************************/
 
 #ifdef CONFIG_PIC
@@ -99,6 +99,36 @@ do { \
  * Public Types
  ****************************************************************************/
 
+#ifdef CONFIG_ARCH_ADDRENV
+/* The task group resources are retained in a single structure, task_group_s
+ * that is defined in the header file nuttx/include/nuttx/sched.h. The type
+ * group_addrenv_t must be defined by platform specific logic in
+ * nuttx/arch/<architecture>/include/arch.h.
+ *
+ * These tables would hold the physical address of the level 2 page tables.
+ * All would be initially NULL and would not be backed up with physical memory
+ * until mappings in the level 2 page table are required.
+ */
+
+struct group_addrenv_s
+{
+  FAR uint32_t *text[CONFIG_ARCH_TEXT_NPAGES];
+  FAR uint32_t *data[CONFIG_ARCH_DATA_NPAGES];
+  FAR uint32_t *heap[CONFIG_ARCH_HEAP_NPAGES];
+};
+
+typedef struct group_addrenv_s group_addrenv_t;
+
+/* This type is used when the OS needs to temporarily instantiate a
+ * different address environment.  Used in the implementation of
+ *
+ *   int up_addrenv_select(group_addrenv_t addrenv, save_addrenv_t *oldenv);
+ *   int up_addrenv_restore(save_addrenv_t oldenv);
+ */
+
+typedef group_addrenv_t *save_addrenv_t;
+#endif
+
 /****************************************************************************
  * Public Variables
  ****************************************************************************/

arch/arm/include/armv7-a/irq.h

@@ -240,6 +240,16 @@ struct xcptcontext
 #ifdef CONFIG_PAGING
   uintptr_t far;
 #endif
+
+#ifdef CONFIG_ARCH_ADDRENV
+  /* This table holds the physical address of the level 2 page table used
+   * to map the thread's stack memory.  This array will be initially of
+   * zeroed and would be back-up up with pages during page fault exception
+   * handling to support dynamically sized stacks for each thread.
+   */
+
+  FAR uint32_t *stack[CONFIG_ARCH_STACK_NPAGES];
+#endif
 };
 #endif
 

arch/arm/src/armv7-a/arm_addrenv.c

@@ -70,6 +70,7 @@
 #include <errno.h>
 
 #include <nuttx/arch.h>
+#include <nuttx/addrenv.h>
 #include <arch/arch.h>
 
 #ifdef CONFIG_ARCH_ADDRENV
@@ -77,6 +78,7 @@
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
+/* Configuration ************************************************************/
 
 /****************************************************************************
  * Private Data
@@ -95,7 +97,7 @@
  *
  * Description:
  *   This function is called when a new task is created in order to
- *   instantiate an address environment for the new task group. 
+ *   instantiate an address environment for the new task group.
  *   up_addrenv_create() is essentially the allocator of the physical
  *   memory for the new task.
  *
@@ -187,7 +189,7 @@ int up_addrenv_vaddr(FAR group_addrenv_t addrenv, FAR void **vaddr)
  *
  ****************************************************************************/
 
-int up_addrenv_select(group_addrenv_t addrenv, hw_addrenv_t *oldenv)
+int up_addrenv_select(group_addrenv_t addrenv, save_addrenv_t *oldenv)
 {
 #warning Missing logic
   return -ENOSYS;
@@ -210,7 +212,7 @@ int up_addrenv_select(group_addrenv_t addrenv, hw_addrenv_t *oldenv)
  *
  ****************************************************************************/
 
-int up_addrenv_restore(hw_addrenv_t oldenv)
+int up_addrenv_restore(save_addrenv_t oldenv)
 {
 #warning Missing logic
   return -ENOSYS;

arch/z80/include/z180/arch.h

@@ -65,7 +65,7 @@
  */
 
 #ifdef CONFIG_ARCH_ADDRENV
-typedef uint8_t hw_addrenv_t;
+typedef uint8_t save_addrenv_t;
 
 /* At the task-level, the z180 address environment is represented as struct
  * z180_cbr_s which is defined in irq.h.

arch/z80/src/z180/z180_mmu.c

@@ -378,7 +378,7 @@ int up_addrenv_vaddr(FAR group_addrenv_t addrenv, FAR void **vaddr)
  *
  ****************************************************************************/
 
-int up_addrenv_select(group_addrenv_t addrenv, hw_addrenv_t *oldenv)
+int up_addrenv_select(group_addrenv_t addrenv, save_addrenv_t *oldenv)
 {
   FAR struct z180_cbr_s *cbr = (FAR struct z180_cbr_s *)addrenv;
   irqstate_t flags;
@@ -388,7 +388,7 @@ int up_addrenv_select(group_addrenv_t addrenv, hw_addrenv_t *oldenv)
   /* Return the current CBR value from the CBR register */
 
   flags = irqsave();
-  *oldenv = (hw_addrenv_t)inp(Z180_MMU_CBR);
+  *oldenv = (save_addrenv_t)inp(Z180_MMU_CBR);
 
   /* Write the new CBR value into CBR register */
 
@@ -414,7 +414,7 @@ int up_addrenv_select(group_addrenv_t addrenv, hw_addrenv_t *oldenv)
  *
  ****************************************************************************/
 
-int up_addrenv_restore(hw_addrenv_t oldenv)
+int up_addrenv_restore(save_addrenv_t oldenv)
 {
   outp(Z180_MMU_CBR, (uint8_t)oldenv);
   return OK;