semihosting: move semihosting configuration into its own directory

In preparation for having some more common semihosting code let's
excise the current config magic from vl.c into its own file. We shall
later add more conditionals to the build configurations so we can
avoid building this if we don't need it.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

4 files changed, 163 insertions, 1 deletions

diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index 82aa7fab8e..d770926ba9 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -36,6 +36,7 @@ devices-dirs-$(CONFIG_SOFTMMU) += watchdog/
 devices-dirs-$(CONFIG_SOFTMMU) += xen/
 devices-dirs-$(CONFIG_MEM_DEVICE) += mem/
 devices-dirs-$(CONFIG_SOFTMMU) += smbios/
+devices-dirs-y += semihosting/
 devices-dirs-y += core/
 common-obj-y += $(devices-dirs-y)
 obj-y += $(devices-dirs-y)
diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c
index 439665ab45..3b009fda25 100644
--- a/hw/mips/mips_malta.c
+++ b/hw/mips/mips_malta.c
@@ -55,7 +55,7 @@
 #include "qemu/error-report.h"
 #include "hw/empty_slot.h"
 #include "sysemu/kvm.h"
-#include "exec/semihost.h"
+#include "hw/semihosting/semihost.h"
 #include "hw/mips/cps.h"
 
 #define ENVP_ADDR		0x80002000l
diff --git a/hw/semihosting/Makefile.objs b/hw/semihosting/Makefile.objs
new file mode 100644
index 0000000000..546954f4ff
--- /dev/null
+++ b/hw/semihosting/Makefile.objs
@@ -0,0 +1 @@
+common-obj-$(CONFIG_SOFTMMU) += config.o
diff --git a/hw/semihosting/config.c b/hw/semihosting/config.c
new file mode 100644
index 0000000000..f1d3fe1e4c
--- /dev/null
+++ b/hw/semihosting/config.c
@@ -0,0 +1,160 @@
+/*
+ * Semihosting configuration
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Copyright (c) 2019 Linaro Ltd
+ *
+ * This controls the configuration of semihosting for all guest
+ * targets that support it. Architecture specific handling is handled
+ * in target/HW/HW-semi.c
+ *
+ * Semihosting is sightly strange in that it is also supported by some
+ * linux-user targets. However in that use case no configuration of
+ * the outputs and command lines is supported.
+ *
+ * The config module is common to all softmmu targets however as vl.c
+ * needs to link against the helpers.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/option.h"
+#include "qemu/config-file.h"
+#include "qemu/error-report.h"
+#include "hw/semihosting/semihost.h"
+
+QemuOptsList qemu_semihosting_config_opts = {
+    .name = "semihosting-config",
+    .implied_opt_name = "enable",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_semihosting_config_opts.head),
+    .desc = {
+        {
+            .name = "enable",
+            .type = QEMU_OPT_BOOL,
+        }, {
+            .name = "target",
+            .type = QEMU_OPT_STRING,
+        }, {
+            .name = "arg",
+            .type = QEMU_OPT_STRING,
+        },
+        { /* end of list */ }
+    },
+};
+
+typedef struct SemihostingConfig {
+    bool enabled;
+    SemihostingTarget target;
+    const char **argv;
+    int argc;
+    const char *cmdline; /* concatenated argv */
+} SemihostingConfig;
+
+static SemihostingConfig semihosting;
+
+bool semihosting_enabled(void)
+{
+    return semihosting.enabled;
+}
+
+SemihostingTarget semihosting_get_target(void)
+{
+    return semihosting.target;
+}
+
+const char *semihosting_get_arg(int i)
+{
+    if (i >= semihosting.argc) {
+        return NULL;
+    }
+    return semihosting.argv[i];
+}
+
+int semihosting_get_argc(void)
+{
+    return semihosting.argc;
+}
+
+const char *semihosting_get_cmdline(void)
+{
+    if (semihosting.cmdline == NULL && semihosting.argc > 0) {
+        semihosting.cmdline = g_strjoinv(" ", (gchar **)semihosting.argv);
+    }
+    return semihosting.cmdline;
+}
+
+static int add_semihosting_arg(void *opaque,
+                               const char *name, const char *val,
+                               Error **errp)
+{
+    SemihostingConfig *s = opaque;
+    if (strcmp(name, "arg") == 0) {
+        s->argc++;
+        /* one extra element as g_strjoinv() expects NULL-terminated array */
+        s->argv = g_realloc(s->argv, (s->argc + 1) * sizeof(void *));
+        s->argv[s->argc - 1] = val;
+        s->argv[s->argc] = NULL;
+    }
+    return 0;
+}
+
+/* Use strings passed via -kernel/-append to initialize semihosting.argv[] */
+void semihosting_arg_fallback(const char *file, const char *cmd)
+{
+    char *cmd_token;
+
+    /* argv[0] */
+    add_semihosting_arg(&semihosting, "arg", file, NULL);
+
+    /* split -append and initialize argv[1..n] */
+    cmd_token = strtok(g_strdup(cmd), " ");
+    while (cmd_token) {
+        add_semihosting_arg(&semihosting, "arg", cmd_token, NULL);
+        cmd_token = strtok(NULL, " ");
+    }
+}
+
+void qemu_semihosting_enable(void)
+{
+    semihosting.enabled = true;
+    semihosting.target = SEMIHOSTING_TARGET_AUTO;
+}
+
+int qemu_semihosting_config_options(const char *optarg)
+{
+    QemuOptsList *opt_list = qemu_find_opts("semihosting-config");
+    QemuOpts *opts = qemu_opts_parse_noisily(opt_list, optarg, false);
+
+    semihosting.enabled = true;
+
+    if (opts != NULL) {
+        semihosting.enabled = qemu_opt_get_bool(opts, "enable",
+                                                true);
+        const char *target = qemu_opt_get(opts, "target");
+        if (target != NULL) {
+            if (strcmp("native", target) == 0) {
+                semihosting.target = SEMIHOSTING_TARGET_NATIVE;
+            } else if (strcmp("gdb", target) == 0) {
+                semihosting.target = SEMIHOSTING_TARGET_GDB;
+            } else  if (strcmp("auto", target) == 0) {
+                semihosting.target = SEMIHOSTING_TARGET_AUTO;
+            } else {
+                error_report("unsupported semihosting-config %s",
+                             optarg);
+                return 1;
+            }
+        } else {
+            semihosting.target = SEMIHOSTING_TARGET_AUTO;
+        }
+        /* Set semihosting argument count and vector */
+        qemu_opt_foreach(opts, add_semihosting_arg,
+                         &semihosting, NULL);
+    } else {
+        error_report("unsupported semihosting-config %s", optarg);
+        return 1;
+    }
+
+    return 0;
+}
+