From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44786) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xz2j9-00059g-Mw for qemu-devel@nongnu.org; Thu, 11 Dec 2014 07:20:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xz2j8-0007WQ-77 for qemu-devel@nongnu.org; Thu, 11 Dec 2014 07:20:15 -0500 Received: from mnementh.archaic.org.uk ([2001:8b0:1d0::1]:54567) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xz2j7-0006sg-Uy for qemu-devel@nongnu.org; Thu, 11 Dec 2014 07:20:14 -0500 Received: from pm215 by mnementh.archaic.org.uk with local (Exim 4.80) (envelope-from ) id 1Xz2ip-00018j-Ed for qemu-devel@nongnu.org; Thu, 11 Dec 2014 12:19:55 +0000 From: Peter Maydell Date: Thu, 11 Dec 2014 12:19:24 +0000 Message-Id: <1418300395-4348-3-git-send-email-peter.maydell@linaro.org> In-Reply-To: <1418300395-4348-1-git-send-email-peter.maydell@linaro.org> References: <1418300395-4348-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PULL 02/33] Add the "-semihosting-config" option. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org From: Liviu Ionescu The usual semihosting behaviour is to process the system calls locally and return; unfortuantelly the initial implementation dinamically changed the target to GDB during debug sessions, which, for the usual arm-none-eabi-gdb, is not implemented. The result was that during debug sessions the semihosting calls were discarded. This patch adds a configuration variable and an option to set it on the command line: -semihosting-config [enable=on|off,]target=native|gdb|auto This option enables semihosting and defines where the semihosting calls will be addressed, to QEMU ('native') or to GDB ('gdb'). The default is auto, which means 'gdb' during debug sessions and 'native' otherwise. Signed-off-by: Liviu Ionescu Message-id: 1416341957-9796-1-git-send-email-ilg@livius.net [PMM: moved declaration and definition of semihosting_target to gdbstub.h and gdbstub.c to fix build failure on linux-user] Signed-off-by: Peter Maydell --- gdbstub.c | 15 +++++++++++++-- include/exec/gdbstub.h | 6 ++++++ qemu-options.hx | 12 +++++++++++- vl.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 78 insertions(+), 3 deletions(-) diff --git a/gdbstub.c b/gdbstub.c index 0faca56..e4a1a79 100644 --- a/gdbstub.c +++ b/gdbstub.c @@ -317,6 +317,8 @@ static GDBState *gdbserver_state; bool gdb_has_xml; +int semihosting_target = SEMIHOSTING_TARGET_AUTO; + #ifdef CONFIG_USER_ONLY /* XXX: This is not thread safe. Do we care? */ static int gdbserver_fd = -1; @@ -351,10 +353,19 @@ static enum { GDB_SYS_DISABLED, } gdb_syscall_mode; -/* If gdb is connected when the first semihosting syscall occurs then use - remote gdb syscalls. Otherwise use native file IO. */ +/* Decide if either remote gdb syscalls or native file IO should be used. */ int use_gdb_syscalls(void) { + if (semihosting_target == SEMIHOSTING_TARGET_NATIVE) { + /* -semihosting-config target=native */ + return false; + } else if (semihosting_target == SEMIHOSTING_TARGET_GDB) { + /* -semihosting-config target=gdb */ + return true; + } + + /* -semihosting-config target=auto */ + /* On the first call check if gdb is connected and remember. */ if (gdb_syscall_mode == GDB_SYS_UNKNOWN) { gdb_syscall_mode = (gdbserver_state ? GDB_SYS_ENABLED : GDB_SYS_DISABLED); diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h index a608a26..c633248 100644 --- a/include/exec/gdbstub.h +++ b/include/exec/gdbstub.h @@ -95,4 +95,10 @@ extern bool gdb_has_xml; /* in gdbstub-xml.c, generated by scripts/feature_to_c.sh */ extern const char *const xml_builtin[][2]; +/* Command line option defining whether semihosting should go via gdb or not */ +extern int semihosting_target; +#define SEMIHOSTING_TARGET_AUTO 0 +#define SEMIHOSTING_TARGET_NATIVE 1 +#define SEMIHOSTING_TARGET_GDB 2 + #endif diff --git a/qemu-options.hx b/qemu-options.hx index 64af16d..afab995 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3218,7 +3218,17 @@ DEF("semihosting", 0, QEMU_OPTION_semihosting, STEXI @item -semihosting @findex -semihosting -Semihosting mode (ARM, M68K, Xtensa only). +Enable semihosting mode (ARM, M68K, Xtensa only). +ETEXI +DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, + "-semihosting-config [enable=on|off,]target=native|gdb|auto semihosting configuration\n", +QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32) +STEXI +@item -semihosting-config [enable=on|off,]target=native|gdb|auto +@findex -semihosting-config +Enable semihosting and define where the semihosting calls will be addressed, +to QEMU (@code{native}) or to GDB (@code{gdb}). The default is @code{auto}, which means +@code{gdb} during debug sessions and @code{native} otherwise (ARM, M68K, Xtensa only). ETEXI DEF("old-param", 0, QEMU_OPTION_old_param, "-old-param old param mode\n", QEMU_ARCH_ARM) diff --git a/vl.c b/vl.c index eb89d62..7cdfd49 100644 --- a/vl.c +++ b/vl.c @@ -554,6 +554,22 @@ static QemuOptsList qemu_icount_opts = { }, }; +static 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, + }, + { /* end of list */ } + }, +}; + /** * Get machine options * @@ -2811,6 +2827,7 @@ int main(int argc, char **argv, char **envp) qemu_add_opts(&qemu_name_opts); qemu_add_opts(&qemu_numa_opts); qemu_add_opts(&qemu_icount_opts); + qemu_add_opts(&qemu_semihosting_config_opts); runstate_init(); @@ -3618,6 +3635,37 @@ int main(int argc, char **argv, char **envp) break; case QEMU_OPTION_semihosting: semihosting_enabled = 1; + semihosting_target = SEMIHOSTING_TARGET_AUTO; + break; + case QEMU_OPTION_semihosting_config: + semihosting_enabled = 1; + opts = qemu_opts_parse(qemu_find_opts("semihosting-config"), + optarg, 0); + 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 { + fprintf(stderr, "Unsupported semihosting-config" + " %s\n", + optarg); + exit(1); + } + } else { + semihosting_target = SEMIHOSTING_TARGET_AUTO; + } + } else { + fprintf(stderr, "Unsupported semihosting-config %s\n", + optarg); + exit(1); + } break; case QEMU_OPTION_tdf: fprintf(stderr, "Warning: user space PIT time drift fix " -- 1.9.1