Fix ARMv6-M/ARMv7-M SVCall register corruption in protected builds, fix lm3s6965-ek:qemu-protected boot, and add board documentation.

Documentation/platforms/arm/tiva/boards/lm3s6965-ek/index.rst

@@ -0,0 +1,169 @@
+===========
+lm3s6965-ek
+===========
+
+The `Stellaris LM3S6965 Evaluation Kit
+<https://www.ti.com/tool/EK-LM3S6965>`_ is an ARM Cortex-M3 based
+development board featuring the LM3S6965 microcontroller with an
+integrated 10/100 Ethernet controller. NuttX can run on this board
+both on real hardware and under QEMU emulation
+(``qemu-system-arm -M lm3s6965evb``).
+
+Features of the LM3S6965 Evaluation Kit:
+
+* LM3S6965 microcontroller (ARM Cortex-M3, 50 MHz)
+* 256 KB flash, 64 KB SRAM
+* Integrated 10/100 Ethernet MAC and PHY
+* OLED graphics display (128 x 96 pixel)
+* MicroSD card slot
+* USB interface for debugging and power supply
+* Standard ARM 20-pin JTAG debug connector
+
+Configurations
+==============
+
+Each configuration is maintained in a sub-directory and can be selected
+as follows::
+
+    $ ./tools/configure.sh lm3s6965-ek:<subdir>
+
+Where ``<subdir>`` is one of the following:
+
+discover
+--------
+
+A network discovery configuration::
+
+    $ ./tools/configure.sh -l lm3s6965-ek:discover
+    $ make
+
+nsh
+---
+
+Configures the NuttShell (NSH) with serial and telnet interfaces::
+
+    $ ./tools/configure.sh -l lm3s6965-ek:nsh
+    $ make
+
+nx
+--
+
+An NX graphics configuration::
+
+    $ ./tools/configure.sh -l lm3s6965-ek:nx
+    $ make
+
+qemu-flat
+---------
+
+A FLAT memory model configuration for running under QEMU::
+
+    $ ./tools/configure.sh -l lm3s6965-ek:qemu-flat
+    $ make
+
+qemu-protected
+--------------
+
+A PROTECTED memory model configuration for running under QEMU::
+
+    $ ./tools/configure.sh -l lm3s6965-ek:qemu-protected
+    $ make
+
+qemu-kostest
+-------------
+
+A PROTECTED memory model configuration with kernel ostest for running
+under QEMU::
+
+    $ ./tools/configure.sh -l lm3s6965-ek:qemu-kostest
+    $ make
+
+qemu-nxflat
+------------
+
+A FLAT memory model configuration with NXFLAT binary support for running
+under QEMU::
+
+    $ ./tools/configure.sh -l lm3s6965-ek:qemu-nxflat
+    $ make
+
+tcpecho
+-------
+
+A TCP echo server configuration::
+
+    $ ./tools/configure.sh -l lm3s6965-ek:tcpecho
+    $ make
+
+Running with QEMU
+=================
+
+FLAT build (qemu-flat)
+----------------------
+
+::
+
+    $ qemu-system-arm -M lm3s6965evb -nographic \
+        -kernel nuttx.bin
+
+PROTECTED build (qemu-protected, qemu-kostest)
+-----------------------------------------------
+
+The PROTECTED build produces separate kernel and user binaries.
+Use ``-device loader`` to load the user binary at its link address::
+
+    $ qemu-system-arm -M lm3s6965evb -nographic \
+        -kernel nuttx.bin \
+        -device loader,file=nuttx_user.bin,addr=0x20000
+
+With networking (qemu-flat)
+---------------------------
+
+The ``lm3s6965evb`` machine includes a built-in Stellaris Ethernet NIC
+(``stellaris_enet``). To enable user-mode networking with the host,
+add the ``-nic user`` option::
+
+    $ qemu-system-arm -M lm3s6965evb -nographic \
+        -kernel nuttx.bin -nic user
+
+With networking (qemu-protected)
+---------------------------------
+
+For the PROTECTED build, also load the user binary::
+
+    $ qemu-system-arm -M lm3s6965evb -nographic \
+        -kernel nuttx.bin \
+        -device loader,file=nuttx_user.bin,addr=0x20000 \
+        -nic user
+
+To exit QEMU, press ``Ctrl-A`` then ``X``.
+
+Debugging with QEMU
+====================
+
+1. To debug the NuttX ELF with symbols, ensure that the following
+   configuration option is enabled in your defconfig (it is already
+   set in the ``lm3s6965-ek:qemu-protected`` defconfig)::
+
+     CONFIG_DEBUG_SYMBOLS=y
+
+2. Run QEMU at shell terminal 1 with GDB server enabled::
+
+     $ qemu-system-arm -M lm3s6965evb -nographic \
+         -kernel nuttx.bin -S -s
+
+   For a PROTECTED build, also load the userspace binary::
+
+     $ qemu-system-arm -M lm3s6965evb -nographic \
+         -kernel nuttx.bin \
+         -device loader,file=nuttx_user.bin,addr=0x20000 -S -s
+
+3. Run GDB with TUI, connect to QEMU, load NuttX and continue
+   (at shell terminal 2)::
+
+     $ arm-none-eabi-gdb -tui --eval-command='target remote localhost:1234' nuttx
+     (gdb) c
+     Continuing.
+     ^C
+     Program received signal SIGINT, Interrupt.
+     (gdb)

Documentation/platforms/arm/tiva/index.rst

@@ -188,3 +188,12 @@ Jose Pablo Carballo and I are doing this port.
 - TI/Tiva TM4C129E
 - TI/Tiva TM4C129X
 - TI/SimpleLink CC13x2
+
+Supported Boards
+================
+
+.. toctree::
+   :glob:
+   :maxdepth: 1
+
+   boards/*/*

arch/arm/src/armv6-m/arm_dispatch_syscall.S

@@ -89,6 +89,7 @@ arm_dispatch_syscall:
 	lsl r0, r0, #2                             /* R0=Offset of the stub for this syscall */
 	ldr r4, [r4, r0]                           /* R4=Address of the stub for this syscall */
 	blx r4                                     /* Call the stub (modifies lr) */
+	ldr r4, [sp, #0]                           /* Restore r4 */
 	add sp, sp, #32                            /* Destroy the stack frame */
 	mov r2, r0                                 /* R2=Save return value in R2 */
 	mov r0, SYS_syscall_return                 /* R0=SYS_syscall_return */

arch/arm/src/armv7-m/arm_dispatch_syscall.S

@@ -78,9 +78,8 @@
 arm_dispatch_syscall:
 	.cfi_sections	.debug_frame
 	.cfi_startproc
-	mov r11, sp
-	.cfi_register sp, r11
 	sub	sp, sp, #32
+	.cfi_def_cfa_offset 32
 	str	r4, [sp, #0]
 	.cfi_offset r4, 0
 	str	r5, [sp, #4]

boards/arm/tiva/lm3s6965-ek/configs/qemu-protected/defconfig

@@ -34,7 +34,6 @@ CONFIG_EXAMPLES_WGET=y
 CONFIG_FS_BINFS=y
 CONFIG_FS_HOSTFS=y
 CONFIG_FS_PROCFS=y
-CONFIG_FS_TMPFS=y
 CONFIG_INIT_ENTRYPOINT="nsh_main"
 CONFIG_LIBC_DLFCN=y
 CONFIG_LIBC_ELF_RELOCATION_BUFFERCOUNT=64
@@ -103,4 +102,5 @@ CONFIG_TIVA_GPIOG_IRQS=y
 CONFIG_TIVA_SSI0=y
 CONFIG_TIVA_UART0=y
 CONFIG_TIVA_WITH_QEMU=y
+CONFIG_TLS_LOG2_MAXSTACK=11
 CONFIG_UART0_SERIAL_CONSOLE=y

boards/arm/tiva/lm3s6965-ek/scripts/memory.ld

@@ -34,7 +34,7 @@ MEMORY
 
     /* 64Kb of contiguous SRAM */
 
-  ksram (rwx)      : ORIGIN = 0x20000000, LENGTH = 16K
-  usram (rwx)      : ORIGIN = 0x20004000, LENGTH = 16K
-  xsram (rwx)      : ORIGIN = 0x20008000, LENGTH = 32K
+  ksram (rwx)      : ORIGIN = 0x20000000, LENGTH = 20K
+  usram (rwx)      : ORIGIN = 0x20005000, LENGTH = 20K
+  xsram (rwx)      : ORIGIN = 0x2000a000, LENGTH = 24K
 }