On 22/10/19 05:13, Keith Packard wrote:
> Provides a blocking call to read a character from the console by hooking
> into the console input chain. This happens *after* any uart has hooked in,
> so specifying -semihost overrides input to any emulated uarts.
>
> Signed-off-by: Keith Packard <kei...@keithp.com>
I'm a bit confused, why is it not using semihosting_get_chardev? That
would be
-chardev stdio,id=semihost
-semihosting-config on,chardev=semihost
Paolo
> ---
> hw/semihosting/console.c | 92 +++++++++++++++++++++++++++++++
> include/hw/semihosting/console.h | 12 ++++
> include/hw/semihosting/semihost.h | 1 +
> stubs/semihost.c | 4 ++
> target/arm/arm-semi.c | 3 +-
> vl.c | 3 +
> 6 files changed, 113 insertions(+), 2 deletions(-)
>
> diff --git a/hw/semihosting/console.c b/hw/semihosting/console.c
> index b4b17c8afb..7345e2cce0 100644
> --- a/hw/semihosting/console.c
> +++ b/hw/semihosting/console.c
> @@ -98,3 +98,95 @@ void qemu_semihosting_console_outc(CPUArchState *env,
> target_ulong addr)
> __func__, addr);
> }
> }
> +
> +#include <pthread.h>
> +#include "chardev/char-fe.h"
> +#include "sysemu/sysemu.h"
> +#include "qemu/main-loop.h"
> +#include "qapi/error.h"
> +
> +#define FIFO_SIZE 1024
> +
> +typedef struct SemihostingFifo {
> + unsigned int insert, remove;
> +
> + uint8_t fifo[FIFO_SIZE];
> +} SemihostingFifo;
> +
> +#define fifo_insert(f, c) do { \
> + (f)->fifo[(f)->insert] = (c); \
> + (f)->insert = ((f)->insert + 1) & (FIFO_SIZE - 1); \
> +} while (0)
> +
> +#define fifo_remove(f, c) do {\
> + c = (f)->fifo[(f)->remove]; \
> + (f)->remove = ((f)->remove + 1) & (FIFO_SIZE - 1); \
> +} while (0)
> +
> +#define fifo_full(f) ((((f)->insert + 1) & (FIFO_SIZE - 1)) == \
> + (f)->remove)
> +#define fifo_empty(f) ((f)->insert == (f)->remove)
> +#define fifo_space(f) (((f)->remove - ((f)->insert + 1)) & \
> + (FIFO_SIZE - 1))
> +
> +typedef struct SemihostingConsole {
> + CharBackend backend;
> + pthread_mutex_t mutex;
> + pthread_cond_t cond;
> + bool got;
> + SemihostingFifo fifo;
> +} SemihostingConsole;
> +
> +static SemihostingConsole console = {
> + .mutex = PTHREAD_MUTEX_INITIALIZER,
> + .cond = PTHREAD_COND_INITIALIZER
> +};
> +
> +static int console_can_read(void *opaque)
> +{
> + SemihostingConsole *c = opaque;
> + int ret;
> + pthread_mutex_lock(&c->mutex);
> + ret = fifo_space(&c->fifo);
> + pthread_mutex_unlock(&c->mutex);
> + return ret;
> +}
> +
> +static void console_read(void *opaque, const uint8_t *buf, int size)
> +{
> + SemihostingConsole *c = opaque;
> + pthread_mutex_lock(&c->mutex);
> + while (size-- && !fifo_full(&c->fifo)) {
> + fifo_insert(&c->fifo, *buf++);
> + }
> + pthread_cond_broadcast(&c->cond);
> + pthread_mutex_unlock(&c->mutex);
> +}
> +
> +target_ulong qemu_semihosting_console_inc(CPUArchState *env)
> +{
> + (void) env;
> + SemihostingConsole *c = &console;
> + qemu_mutex_unlock_iothread();
> + pthread_mutex_lock(&c->mutex);
> + while (fifo_empty(&c->fifo)) {
> + pthread_cond_wait(&c->cond, &c->mutex);
> + }
> + uint8_t ch;
> + fifo_remove(&c->fifo, ch);
> + pthread_mutex_unlock(&c->mutex);
> + qemu_mutex_lock_iothread();
> + return (target_ulong) ch;
> +}
> +
> +void qemu_semihosting_console_init(void)
> +{
> + if (semihosting_enabled()) {
> + qemu_chr_fe_init(&console.backend, serial_hd(0), &error_abort);
> + qemu_chr_fe_set_handlers(&console.backend,
> + console_can_read,
> + console_read,
> + NULL, NULL, &console,
> + NULL, true);
> + }
> +}
> diff --git a/include/hw/semihosting/console.h
> b/include/hw/semihosting/console.h
> index 9be9754bcd..56f3606a2a 100644
> --- a/include/hw/semihosting/console.h
> +++ b/include/hw/semihosting/console.h
> @@ -37,6 +37,18 @@ int qemu_semihosting_console_outs(CPUArchState *env,
> target_ulong s);
> */
> void qemu_semihosting_console_outc(CPUArchState *env, target_ulong c);
>
> +/**
> + * qemu_semihosting_console_outc:
> + * @env: CPUArchState
> + *
> + * Receive single character from debug console. This
> + * may be the remote gdb session if a softmmu guest is currently being
> + * debugged.
> + *
> + * Returns: character read or -1 on error
> + */
> +target_ulong qemu_semihosting_console_inc(CPUArchState *env);
> +
> /**
> * qemu_semihosting_log_out:
> * @s: pointer to string
> diff --git a/include/hw/semihosting/semihost.h
> b/include/hw/semihosting/semihost.h
> index 60fc42d851..a13d17c087 100644
> --- a/include/hw/semihosting/semihost.h
> +++ b/include/hw/semihosting/semihost.h
> @@ -68,6 +68,7 @@ Chardev *semihosting_get_chardev(void);
> void qemu_semihosting_enable(void);
> int qemu_semihosting_config_options(const char *opt);
> void qemu_semihosting_connect_chardevs(void);
> +void qemu_semihosting_console_init(void);
> #endif /* CONFIG_USER_ONLY */
>
> #endif /* SEMIHOST_H */
> diff --git a/stubs/semihost.c b/stubs/semihost.c
> index f90589259c..1d8b37f7b2 100644
> --- a/stubs/semihost.c
> +++ b/stubs/semihost.c
> @@ -69,3 +69,7 @@ void semihosting_arg_fallback(const char *file, const char
> *cmd)
> void qemu_semihosting_connect_chardevs(void)
> {
> }
> +
> +void qemu_semihosting_console_init(void)
> +{
> +}
> diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c
> index 6f7b6d801b..47d61f6fe1 100644
> --- a/target/arm/arm-semi.c
> +++ b/target/arm/arm-semi.c
> @@ -802,8 +802,7 @@ target_ulong do_arm_semihosting(CPUARMState *env)
>
> return guestfd_fns[gf->type].readfn(cpu, gf, arg1, len);
> case TARGET_SYS_READC:
> - qemu_log_mask(LOG_UNIMP, "%s: SYS_READC not implemented", __func__);
> - return 0;
> + return qemu_semihosting_console_inc(env);
> case TARGET_SYS_ISTTY:
> GET_ARG(0);
>
> diff --git a/vl.c b/vl.c
> index 4489cfb2bb..ac584d97ea 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -4381,6 +4381,9 @@ int main(int argc, char **argv, char **envp)
> ds = init_displaystate();
> qemu_display_init(ds, &dpy);
>
> + /* connect semihosting console input if requested */
> + qemu_semihosting_console_init();
> +
> /* must be after terminal init, SDL library changes signal handlers */
> os_setup_signal_handling();
>
>
