semihosting: Add GuestFDConsole

Add a GuestFDType for connecting to the semihosting console.
Hook up to read, write, isatty, and fstat syscalls.

Note that the arm-specific syscall flen cannot be applied
to the console, because the console is not a descriptor
exposed to the guest.

Reviewed-by: Luc Michel <lmichel@kalray.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2022-05-01 13:11:45 -07:00
parent cd66f20f61
commit 008e147572
2 changed files with 72 additions and 3 deletions

View File

@ -13,9 +13,10 @@
typedef enum GuestFDType {
GuestFDUnused = 0,
GuestFDHost = 1,
GuestFDGDB = 2,
GuestFDStatic = 3,
GuestFDHost,
GuestFDGDB,
GuestFDStatic,
GuestFDConsole,
} GuestFDType;
/*

View File

@ -10,6 +10,7 @@
#include "exec/gdbstub.h"
#include "semihosting/guestfd.h"
#include "semihosting/syscalls.h"
#include "semihosting/console.h"
#ifdef CONFIG_USER_ONLY
#include "qemu.h"
#else
@ -577,6 +578,56 @@ static void staticfile_flen(CPUState *cs, gdb_syscall_complete_cb complete,
complete(cs, gf->staticfile.len, 0);
}
/*
* Console semihosting syscall implementations.
*/
static void console_read(CPUState *cs, gdb_syscall_complete_cb complete,
GuestFD *gf, target_ulong buf, target_ulong len)
{
CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
char *ptr;
int ret;
ptr = lock_user(VERIFY_WRITE, buf, len, 0);
if (!ptr) {
complete(cs, -1, EFAULT);
return;
}
ret = qemu_semihosting_console_read(cs, ptr, len);
complete(cs, ret, 0);
unlock_user(ptr, buf, ret);
}
static void console_write(CPUState *cs, gdb_syscall_complete_cb complete,
GuestFD *gf, target_ulong buf, target_ulong len)
{
CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
char *ptr = lock_user(VERIFY_READ, buf, len, 1);
int ret;
if (!ptr) {
complete(cs, -1, EFAULT);
return;
}
ret = qemu_semihosting_console_write(ptr, len);
complete(cs, ret ? ret : -1, ret ? 0 : EIO);
unlock_user(ptr, buf, ret);
}
static void console_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
GuestFD *gf, target_ulong addr)
{
static const struct stat tty_buf = {
.st_mode = 020666, /* S_IFCHR, ugo+rw */
.st_rdev = 5, /* makedev(5, 0) -- linux /dev/tty */
};
int ret;
ret = copy_stat_to_user(cs, addr, &tty_buf);
complete(cs, ret ? -1 : 0, ret ? -ret : 0);
}
/*
* Syscall entry points.
*/
@ -608,6 +659,7 @@ void semihost_sys_close(CPUState *cs, gdb_syscall_complete_cb complete, int fd)
host_close(cs, complete, gf);
break;
case GuestFDStatic:
case GuestFDConsole:
complete(cs, 0, 0);
break;
default:
@ -637,6 +689,9 @@ void semihost_sys_read_gf(CPUState *cs, gdb_syscall_complete_cb complete,
case GuestFDStatic:
staticfile_read(cs, complete, gf, buf, len);
break;
case GuestFDConsole:
console_read(cs, complete, gf, buf, len);
break;
default:
g_assert_not_reached();
}
@ -672,6 +727,9 @@ void semihost_sys_write_gf(CPUState *cs, gdb_syscall_complete_cb complete,
case GuestFDHost:
host_write(cs, complete, gf, buf, len);
break;
case GuestFDConsole:
console_write(cs, complete, gf, buf, len);
break;
case GuestFDStatic:
/* Static files are never open for writing: EBADF. */
complete(cs, -1, EBADF);
@ -712,6 +770,9 @@ void semihost_sys_lseek(CPUState *cs, gdb_syscall_complete_cb complete,
case GuestFDStatic:
staticfile_lseek(cs, complete, gf, off, gdb_whence);
break;
case GuestFDConsole:
complete(cs, -1, ESPIPE);
break;
default:
g_assert_not_reached();
}
@ -735,6 +796,9 @@ void semihost_sys_isatty(CPUState *cs, gdb_syscall_complete_cb complete, int fd)
case GuestFDStatic:
complete(cs, 0, ENOTTY);
break;
case GuestFDConsole:
complete(cs, 1, 0);
break;
default:
g_assert_not_reached();
}
@ -760,6 +824,7 @@ void semihost_sys_flen(CPUState *cs, gdb_syscall_complete_cb fstat_cb,
case GuestFDStatic:
staticfile_flen(cs, flen_cb, gf);
break;
case GuestFDConsole:
default:
g_assert_not_reached();
}
@ -781,6 +846,9 @@ void semihost_sys_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
case GuestFDHost:
host_fstat(cs, complete, gf, addr);
break;
case GuestFDConsole:
console_fstat(cs, complete, gf, addr);
break;
case GuestFDStatic:
default:
g_assert_not_reached();