semihosting: Move ARM semihosting code to shared directories

This commit renames two files which provide ARM semihosting support so
that they can be shared by other architectures:

 1. target/arm/arm-semi.c     -> hw/semihosting/common-semi.c
 2. linux-user/arm/semihost.c -> linux-user/semihost.c

The build system was modified use a new config variable,
CONFIG_ARM_COMPATIBLE_SEMIHOSTING, which has been added to the ARM
softmmu and linux-user default configs. The contents of the source
files has not been changed in this patch.

Signed-off-by: Keith Packard <keithp@keithp.com>
[AJB: rename arm-compat-semi, select SEMIHOSTING]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210107170717.2098982-2-keithp@keithp.com>
Message-Id: <20210108224256.2321-13-alex.bennee@linaro.org>

default-configs/devices/arm-softmmu.mak

@@ -42,4 +42,5 @@ CONFIG_FSL_IMX25=y
 CONFIG_FSL_IMX7=y
 CONFIG_FSL_IMX6UL=y
 CONFIG_SEMIHOSTING=y
+CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y
 CONFIG_ALLWINNER_H3=y

default-configs/targets/aarch64-linux-user.mak

@@ -2,3 +2,4 @@ TARGET_ARCH=aarch64
 TARGET_BASE_ARCH=arm
 TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
 TARGET_HAS_BFLT=y
+CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y

default-configs/targets/aarch64_be-linux-user.mak

@@ -3,3 +3,4 @@ TARGET_BASE_ARCH=arm
 TARGET_WORDS_BIGENDIAN=y
 TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
 TARGET_HAS_BFLT=y
+CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y

default-configs/targets/arm-linux-user.mak

@@ -3,3 +3,4 @@ TARGET_SYSTBL_ABI=common,oabi
 TARGET_SYSTBL=syscall.tbl
 TARGET_XML_FILES= gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
 TARGET_HAS_BFLT=y
+CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y

default-configs/targets/armeb-linux-user.mak

@@ -4,3 +4,4 @@ TARGET_SYSTBL=syscall.tbl
 TARGET_WORDS_BIGENDIAN=y
 TARGET_XML_FILES= gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
 TARGET_HAS_BFLT=y
+CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y

hw/semihosting/Kconfig

@@ -1,3 +1,7 @@
 
 config SEMIHOSTING
        bool
+
+config ARM_COMPATIBLE_SEMIHOSTING
+       bool
+       select SEMIHOSTING

hw/semihosting/meson.build

@@ -2,3 +2,6 @@ specific_ss.add(when: 'CONFIG_SEMIHOSTING', if_true: files(
   'config.c',
   'console.c',
 ))
+
+specific_ss.add(when: ['CONFIG_ARM_COMPATIBLE_SEMIHOSTING'],
+		if_true: files('arm-compat-semi.c'))

linux-user/arm/meson.build

@@ -1,6 +1,3 @@
-linux_user_ss.add(when: 'TARGET_AARCH64', if_true: files('semihost.c'))
-linux_user_ss.add(when: 'TARGET_ARM', if_true: files('semihost.c'))
-
 subdir('nwfpe')
 
 syscall_nr_generators += {

linux-user/meson.build

@@ -16,6 +16,7 @@ linux_user_ss.add(rt)
 
 linux_user_ss.add(when: 'TARGET_HAS_BFLT', if_true: files('flatload.c'))
 linux_user_ss.add(when: 'TARGET_I386', if_true: files('vm86.c'))
+linux_user_ss.add(when: 'CONFIG_ARM_COMPATIBLE_SEMIHOSTING', if_true: files('semihost.c'))
 
 
 syscall_nr_generators = {}

target/arm/meson.build

@@ -32,8 +32,6 @@ arm_ss.add(files(
 ))
 arm_ss.add(zlib)
 
-arm_ss.add(when: 'CONFIG_TCG', if_true: files('arm-semi.c'))
-
 arm_ss.add(when: 'CONFIG_KVM', if_true: files('kvm.c', 'kvm64.c'), if_false: files('kvm-stub.c'))
 
 arm_ss.add(when: 'TARGET_AARCH64', if_true: files(