Arm64 kernelmode

Documentation/platforms/arm64/qemu/boards/qemu-armv8a/README.txt

@@ -148,6 +148,16 @@ Getting Started
      -device virtio-net-device,netdev=u1,bus=virtio-mmio-bus.0 \
      -mon chardev=con,mode=readline -kernel ./nuttx
 
+  3.5 Single Core /w kernel mode (GICv3)
+   Configuring NuttX and compile:
+   $ ./tools/configure.sh -l qemu-armv8a:knsh
+   $ make
+   Running with qemu
+   $ qemu-system-aarch64 -semihosting -cpu cortex-a53 -nographic \
+     -machine virt,virtualization=on,gic-version=3 \
+     -net none -chardev stdio,id=con,mux=on -serial chardev:con \
+     -mon chardev=con,mode=readline -kernel ./nuttx
+
 Status
 ======
 

arch/Kconfig

@@ -38,6 +38,7 @@ config ARCH_ARM64
 	select ARCH_HAVE_THREAD_LOCAL
 	select ARCH_HAVE_PERF_EVENTS
 	select ONESHOT
+	select LIBC_ARCH_ELF_64BIT if LIBC_ARCH_ELF
 	---help---
 		The ARM64 architectures
 

arch/arm64/Kconfig

@@ -56,7 +56,6 @@ config ARCH_CHIP_QEMU
 	select ARCH_HAVE_POWEROFF
 	select ARCH_HAVE_RESET
 	select ARCH_HAVE_TEXT_HEAP
-	select LIBC_ARCH_ELF_64BIT if LIBC_ARCH_ELF
 	---help---
 		QEMU virt platform (ARMv8a)
 
@@ -71,7 +70,6 @@ config ARCH_CHIP_GOLDFISH
 	select ARCH_HAVE_POWEROFF
 	select ARCH_HAVE_RESET
 	select ARCH_NEED_ADDRENV_MAPPING
-	select LIBC_ARCH_ELF_64BIT if LIBC_ARCH_ELF
 	---help---
 		Android GoldFish platform for NuttX (ARMv8a),
 		based on ARM virt board

arch/arm64/include/arch.h

@@ -33,8 +33,7 @@
 
 #ifndef __ASSEMBLY__
 #  include <stdint.h>
-#  include <nuttx/pgalloc.h>
-#  include <nuttx/addrenv.h>
+#  include <stddef.h>
 #endif
 
 /****************************************************************************
@@ -46,6 +45,11 @@
 #  error Only pages sizes of 4096 are currently supported (CONFIG_ARCH_ADDRENV)
 #endif
 
+/* All implementations have 3 levels of page tables */
+
+#define ARCH_PGT_MAX_LEVELS (3)
+#define ARCH_SPGTS          (ARCH_PGT_MAX_LEVELS - 1)
+
 #endif /* CONFIG_ARCH_ADDRENV */
 
 /****************************************************************************
@@ -57,40 +61,46 @@
  ****************************************************************************/
 
 #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
- * arch_addrenv_t must be defined by platform specific logic in
- * nuttx/arch/<architecture>/include/arch.h.
+#ifndef __ASSEMBLY__
+
+/* A task group must have its L1 table in memory always, and the rest can
+ * be dynamically committed to memory (and even swapped).
  *
- * 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.
+ * In this implementation level tables except the final level N are always
+ * kept in static memory, while the level N tables are always dynamically
+ * allocated. There is one static page per level in `spgtables[]`.
+ *
+ * For the VMSAv8-64 address translation system this means that:
+ * - A task can not have more than 1GB of memory allocated. This should be
+ *   plenty enough...
+ * - The minimum amount of memory needed for page tables per task is 12K,
+ *   which gives access to 2MB of memory. This is plenty for many tasks.
  */
 
 struct arch_addrenv_s
 {
-  /* Level 1 page table entries for each group section */
-
-  uintptr_t *text[ARCH_TEXT_NSECTS];
-  uintptr_t *data[ARCH_DATA_NSECTS];
-#ifdef CONFIG_BUILD_KERNEL
-  uintptr_t *heap[ARCH_HEAP_NSECTS];
-#ifdef CONFIG_ARCH_VMA_MAPPING
-  uintptr_t *shm[ARCH_SHM_NSECTS];
-#endif
-
-  /* Initial heap allocation (in bytes).  This exists only provide an
-   * indirect path for passing the size of the initial heap to the heap
-   * initialization logic.  These operations are separated in time and
-   * architecture.  REVISIT:  I would like a better way to do this.
+  /* Physical addresses of the static page tables (levels N-1) here, these
+   * are allocated when a task is created.
    */
 
-  size_t heapsize;
-#endif
+  uintptr_t spgtables[ARCH_SPGTS];
+
+  /* The text, data, heap bases and heap size here */
+
+  uintptr_t textvbase;
+  uintptr_t datavbase;
+  uintptr_t heapvbase;
+  size_t    heapsize;
+
+  /* The page directory root (ttbr0) value */
+
+  uintptr_t ttbr0;
 };
 
 typedef struct arch_addrenv_s arch_addrenv_t;
-#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* CONFIG_ARCH_ADDRENV */
 
 /****************************************************************************
  * Public Data

arch/arm64/include/irq.h

@@ -192,6 +192,14 @@
 #define XCPTCONTEXT_REGS    (XCPTCONTEXT_GP_REGS + XCPTCONTEXT_FPU_REGS)
 #define XCPTCONTEXT_SIZE    (8 * XCPTCONTEXT_REGS)
 
+#ifdef CONFIG_ARM64_DECODEFIQ
+#  define IRQ_DAIF_MASK (3)
+#else
+#  define IRQ_DAIF_MASK (2)
+#endif
+
+#define IRQ_SPSR_MASK (IRQ_DAIF_MASK << 6)
+
 #ifndef __ASSEMBLY__
 
 #ifdef __cplusplus
@@ -219,6 +227,12 @@ extern "C"
 EXTERN volatile uint64_t *g_current_regs[CONFIG_SMP_NCPUS];
 #define CURRENT_REGS (g_current_regs[up_cpu_index()])
 
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
 struct xcptcontext
 {
   /* The following function pointer is non-zero if there are pending signals
@@ -238,6 +252,9 @@ struct xcptcontext
   /* task stack reg context */
 
   uint64_t *regs;
+#ifndef CONFIG_BUILD_FLAT
+  uint64_t *initregs;
+#endif
 
   /* task context, for signal process */
 
@@ -280,11 +297,12 @@ struct xcptcontext
 
   uintptr_t *ustkptr;  /* Saved user stack pointer */
   uintptr_t *kstack;   /* Allocate base of the (aligned) kernel stack */
-  uintptr_t *kstkptr;  /* Saved kernel stack pointer */
 #  endif
 #endif
 };
 
+#endif /* __ASSEMBLY__ */
+
 /* Name: up_irq_save, up_irq_restore, and friends.
  *
  * NOTE: This function should never be called from application code and,
@@ -314,13 +332,9 @@ static inline irqstate_t up_irq_save(void)
   __asm__ __volatile__
     (
       "mrs %0, daif\n"
-#ifdef CONFIG_ARM64_DECODEFIQ
-      "msr daifset, #3\n"
-#else
-      "msr daifset, #2\n"
-#endif
+      "msr daifset, %1\n"
       : "=r" (flags)
-      :
+      : "i" (IRQ_DAIF_MASK)
       : "memory"
     );
 
@@ -336,13 +350,9 @@ static inline irqstate_t up_irq_enable(void)
   __asm__ __volatile__
     (
       "mrs %0, daif\n"
-#ifdef CONFIG_ARM64_DECODEFIQ
-      "msr daifclr, #3\n"
-#else
-      "msr daifclr, #2\n"
-#endif
+      "msr daifclr, %1\n"
       : "=r" (flags)
-      :
+      : "i" (IRQ_DAIF_MASK)
       : "memory"
     );
   return flags;

arch/arm64/include/syscall.h

@@ -52,7 +52,7 @@
  */
 
 #ifndef CONFIG_BUILD_FLAT
-#  define CONFIG_SYS_RESERVED 8
+#  define CONFIG_SYS_RESERVED 6
 #else
 #  define CONFIG_SYS_RESERVED 4
 #endif
@@ -80,32 +80,7 @@
 
 #define SYS_switch_context        (2)
 
-#ifdef CONFIG_LIB_SYSCALL
-/* SYS call 3:
- *
- * void arm_syscall_return(void);
- */
-
-#define SYS_syscall_return        (3)
-#endif /* CONFIG_LIB_SYSCALL */
-
 #ifndef CONFIG_BUILD_FLAT
-/* SYS call 4:
- *
- * void up_task_start(main_t taskentry, int argc, char *argv[])
- *        noreturn_function;
- */
-
-#define SYS_task_start            (4)
-
-/* SYS call 5:
- *
- * void up_pthread_start((pthread_startroutine_t startup,
- *                        pthread_startroutine_t entrypt, pthread_addr_t arg)
- *        noreturn_function
- */
-
-#define SYS_pthread_start         (5)
 
 /* SYS call 6:
  *
@@ -114,14 +89,14 @@
  *                     void *ucontext);
  */
 
-#define SYS_signal_handler        (6)
+#define SYS_signal_handler        (4)
 
 /* SYS call 7:
  *
  * void signal_handler_return(void);
  */
 
-#define SYS_signal_handler_return (7)
+#define SYS_signal_handler_return (5)
 #endif /* !CONFIG_BUILD_FLAT */
 
 #define ARM_SMCC_RES_A0       (0)

arch/arm64/src/common/Make.defs

@@ -88,23 +88,15 @@ ifeq ($(CONFIG_BUILD_KERNEL),y)
 CMN_CSRCS += arm64_task_start.c arm64_pthread_start.c arm64_signal_dispatch.c
 endif
 
-ifeq ($(CONFIG_ARCH_ADDRENV),y)
-CMN_CSRCS += arm64_addrenv.c arm64_addrenv_utils.c arm64_pgalloc.c
-ifeq ($(CONFIG_ARCH_STACK_DYNAMIC),y)
-CMN_CSRCS += arm64_addrenv_ustack.c
-endif
 ifeq ($(CONFIG_ARCH_KERNEL_STACK),y)
 CMN_CSRCS += arm64_addrenv_kstack.c
 endif
-ifeq ($(CONFIG_ARCH_VMA_MAPPING),y)
-CMN_CSRCS += arm64_addrenv_shm.c
-endif
-endif
 
-ifeq ($(CONFIG_MM_PGALLOC),y)
-CMN_CSRCS += arm64_physpgaddr.c
-ifeq ($(CONFIG_ARCH_PGPOOL_MAPPING),y)
-CMN_CSRCS += arm64_virtpgaddr.c
+ifeq ($(CONFIG_ARCH_ADDRENV),y)
+CMN_CSRCS += arm64_addrenv.c arm64_pgalloc.c arm64_addrenv_perms.c
+CMN_CSRCS += arm64_addrenv_utils.c arm64_addrenv_shm.c arm64_addrenv_pgmap.c
+ifeq ($(CONFIG_ARCH_STACK_DYNAMIC),y)
+CMN_CSRCS += arm64_addrenv_ustack.c
 endif
 endif