qemu: add ARM noMMU defconfig

Useful for testing no-MMU ARM code in Qemu.

The newer Linux kernels with DT support for Qemu Versatile aren't yet
working, so use latest 4.4 kernel.

Signed-off-by: Waldemar Brodkorb <wbx@uclibc-ng.org>
Tested-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

board/qemu/arm-versatile/linux-4.4-nommu.config

@@ -0,0 +1,46 @@
+# CONFIG_MMU is not set
+CONFIG_ARCH_VERSATILE=y
+CONFIG_SET_MEM_PARAM=y
+CONFIG_DRAM_BASE=0x00000000
+CONFIG_DRAM_SIZE=0x08000000
+CONFIG_ARCH_VERSATILE_PB=y
+CONFIG_MACH_VERSATILE_AB=y
+# CONFIG_MACH_VERSATILE_DT is not set
+CONFIG_BINFMT_FLAT=y
+CONFIG_SYSVIPC=y
+CONFIG_MODULES=y
+CONFIG_MODULE_UNLOAD=y
+# CONFIG_ARCH_MULTI_V7 is not set
+CONFIG_AEABI=y
+CONFIG_NET=y
+CONFIG_PACKET=y
+CONFIG_UNIX=y
+CONFIG_INET=y
+CONFIG_NETDEVICES=y
+CONFIG_SMC91X=y
+CONFIG_PHYLIB=y
+CONFIG_INPUT_EVDEV=y
+CONFIG_SERIO_AMBAKMI=y
+CONFIG_LEGACY_PTY_COUNT=16
+CONFIG_SERIAL_8250=m
+CONFIG_SERIAL_8250_EXTENDED=y
+CONFIG_SERIAL_8250_MANY_PORTS=y
+CONFIG_SERIAL_8250_SHARE_IRQ=y
+CONFIG_SERIAL_8250_RSA=y
+CONFIG_SERIAL_AMBA_PL011=y
+CONFIG_SERIAL_AMBA_PL011_CONSOLE=y
+CONFIG_I2C=y
+CONFIG_I2C_CHARDEV=m
+CONFIG_FB=y
+CONFIG_FB_ARMCLCD=y
+CONFIG_FRAMEBUFFER_CONSOLE=y
+CONFIG_SOUND=y
+CONFIG_SND=m
+CONFIG_SND_MIXER_OSS=m
+CONFIG_SND_PCM_OSS=m
+CONFIG_SND_ARMAACI=m
+CONFIG_EXT4_FS=y
+CONFIG_VFAT_FS=m
+CONFIG_TMPFS=y
+CONFIG_TMPFS_POSIX_ACL=y
+CONFIG_MAGIC_SYSRQ=y

board/qemu/arm-versatile/patches/linux/versatile-nommu.patch

@@ -0,0 +1,30 @@
+From b7c1666813424d329868335c8faf8886b0f85b6c Mon Sep 17 00:00:00 2001
+From: Greg Ungerer <gerg@linux-m68k.org>
+Date: Thu, 11 Aug 2016 21:33:11 +1000
+Subject: [PATCH] arm: fix versatile platform to work in no-MMU mode
+
+If CONFIG_MMU is disabled then do not carry out the virtual memory address
+translation for IO devices.
+
+With this fix in place we can run the ARM Versatile board (including its
+qemu emulation) as a no-MMU Linux system.
+
+Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
+Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
+
+diff -Nur linux-4.4.17.orig/arch/arm/mach-versatile/include/mach/hardware.h linux-4.4.17/arch/arm/mach-versatile/include/mach/hardware.h
+--- linux-4.4.17.orig/arch/arm/mach-versatile/include/mach/hardware.h	2016-08-10 11:49:43.000000000 +0200
++++ linux-4.4.17/arch/arm/mach-versatile/include/mach/hardware.h	2016-08-25 23:19:03.691716292 +0200
+@@ -30,8 +30,12 @@
+ #define VERSATILE_PCI_VIRT_BASE		(void __iomem *)0xe8000000ul
+ #define VERSATILE_PCI_CFG_VIRT_BASE	(void __iomem *)0xe9000000ul
+ 
++#ifdef CONFIG_MMU
+ /* macro to get at MMIO space when running virtually */
+ #define IO_ADDRESS(x)		(((x) & 0x0fffffff) + (((x) >> 4) & 0x0f000000) + 0xf0000000)
++#else
++#define IO_ADDRESS(x)		(x)
++#endif
+ 
+ #define __io_address(n)		((void __iomem __force *)IO_ADDRESS(n))
+ 

board/qemu/arm-versatile/readme.txt

@@ -2,6 +2,10 @@ Run the emulation with:
 
   qemu-system-arm -M versatilepb -kernel output/images/zImage -dtb output/images/versatile-pb.dtb -drive file=output/images/rootfs.ext2,if=scsi,format=raw -append "root=/dev/sda console=ttyAMA0,115200" -serial stdio -net nic,model=rtl8139 -net user
 
+Or for the noMMU emulation:
+
+  qemu-system-arm -M versatilepb -kernel output/images/zImage -append "console=ttyAMA0,115200" -serial stdio -net user -net nic,model=smc91c111
+
 The login prompt will appear in the terminal that started Qemu. The
 graphical window is the framebuffer.
 

configs/qemu_arm_versatile_nommu_defconfig

@@ -0,0 +1,32 @@
+# Architecture
+BR2_arm=y
+BR2_arm926t=y
+
+# Toolchain
+BR2_PACKAGE_HOST_ELF2FLT=y
+# BR2_USE_MMU is not set
+
+# Patches
+BR2_GLOBAL_PATCH_DIR="board/qemu/arm-versatile/patches"
+
+# Busybox with hush
+BR2_PACKAGE_BUSYBOX_CONFIG="package/busybox/busybox-minimal.config"
+
+# System
+BR2_SYSTEM_DHCP="eth0"
+BR2_TARGET_GENERIC_GETTY_PORT="ttyAMA0"
+
+# Filesystem
+# BR2_TARGET_ROOTFS_EXT2 is not set
+# BR2_TARGET_ROOTFS_TAR is not set
+BR2_TARGET_ROOTFS_INITRAMFS=y
+
+# Linux headers same as kernel, a 4.4 series
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_4=y
+
+# Kernel
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.4.22"
+BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
+BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/qemu/arm-versatile/linux-4.4-nommu.config"