Add support for Semihosting v2 support for ARM in libgloss.
Semihosting v2 changes are documented here: https://developer.arm.com/docs/100863/latest/ The biggest change is the addition of an extensions mechanism to add more extensions in the future. Signed-off-by: Tamar Christina <tamar.christina@arm.com>
This commit is contained in:
Tamar Christina
committed by
Corinna Vinschen
Corinna Vinschen
parent
cc142edbe7
commit
d7d6ad7b6b
@ -47,6 +47,9 @@ static int checkerror _PARAMS ((int));
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static int error _PARAMS ((int));
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static int get_errno _PARAMS ((void));
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/* Semihosting utilities. */
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static void initialise_semihosting_exts _PARAMS ((void));
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/* Struct used to keep track of the file position, just so we
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can implement fseek(fh,x,SEEK_CUR). */
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struct fdent
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@ -95,6 +98,9 @@ static int monitor_stdin;
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static int monitor_stdout;
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static int monitor_stderr;
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static int supports_ext_exit_extended = -1;
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static int supports_ext_stdout_stderr = -1;
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/* Return a pointer to the structure associated with
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the user file descriptor fd. */
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static struct fdent*
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@ -154,15 +160,21 @@ initialise_monitor_handles (void)
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block[1] = 0; /* mode "r" */
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monitor_stdin = do_AngelSWI (AngelSWI_Reason_Open, (void *) block);
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block[0] = (int) ":tt";
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block[2] = 3; /* length of filename */
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block[1] = 4; /* mode "w" */
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monitor_stdout = do_AngelSWI (AngelSWI_Reason_Open, (void *) block);
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for (i = 0; i < MAX_OPEN_FILES; i ++)
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openfiles[i].handle = -1;
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block[0] = (int) ":tt";
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block[2] = 3; /* length of filename */
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block[1] = 8; /* mode "a" */
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monitor_stderr = do_AngelSWI (AngelSWI_Reason_Open, (void *) block);
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if (_has_ext_stdout_stderr ())
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{
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block[0] = (int) ":tt";
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block[2] = 3; /* length of filename */
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block[1] = 4; /* mode "w" */
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monitor_stdout = do_AngelSWI (AngelSWI_Reason_Open, (void *) block);
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block[0] = (int) ":tt";
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block[2] = 3; /* length of filename */
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block[1] = 8; /* mode "a" */
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monitor_stderr = do_AngelSWI (AngelSWI_Reason_Open, (void *) block);
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}
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#else
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int fh;
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const char * name;
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@ -174,34 +186,135 @@ initialise_monitor_handles (void)
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: "r0","r1");
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monitor_stdin = fh;
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name = ":tt";
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asm ("mov r0,%2; mov r1, #4; swi %a1; mov %0, r0"
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: "=r"(fh)
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: "i" (SWI_Open),"r"(name)
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: "r0","r1");
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monitor_stdout = fh;
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if (_has_ext_stdout_stderr ())
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{
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name = ":tt";
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asm ("mov r0,%2; mov r1, #4; swi %a1; mov %0, r0"
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: "=r"(fh)
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: "i" (SWI_Open),"r"(name)
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: "r0","r1");
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monitor_stdout = fh;
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name = ":tt";
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asm ("mov r0,%2; mov r1, #8; swi %a1; mov %0, r0"
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: "=r"(fh)
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: "i" (SWI_Open),"r"(name)
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: "r0","r1");
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monitor_stderr = fh;
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name = ":tt";
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asm ("mov r0,%2; mov r1, #8; swi %a1; mov %0, r0"
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: "=r"(fh)
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: "i" (SWI_Open),"r"(name)
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: "r0","r1");
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monitor_stderr = fh;
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}
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#endif
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/* If we failed to open stderr, redirect to stdout. */
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if (monitor_stderr == -1)
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monitor_stderr = monitor_stdout;
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for (i = 0; i < MAX_OPEN_FILES; i ++)
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openfiles[i].handle = -1;
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openfiles[0].handle = monitor_stdin;
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openfiles[0].pos = 0;
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openfiles[1].handle = monitor_stdout;
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openfiles[1].pos = 0;
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openfiles[2].handle = monitor_stderr;
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openfiles[2].pos = 0;
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if (_has_ext_stdout_stderr ())
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{
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openfiles[1].handle = monitor_stdout;
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openfiles[1].pos = 0;
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openfiles[2].handle = monitor_stderr;
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openfiles[2].pos = 0;
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}
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}
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int
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_has_ext_exit_extended (void)
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{
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if (supports_ext_exit_extended < 0)
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{
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initialise_semihosting_exts ();
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}
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return supports_ext_exit_extended;
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}
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int
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_has_ext_stdout_stderr (void)
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{
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if (supports_ext_stdout_stderr < 0)
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{
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initialise_semihosting_exts ();
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}
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return supports_ext_stdout_stderr;
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}
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static void
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initialise_semihosting_exts (void)
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{
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supports_ext_exit_extended = 0;
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supports_ext_stdout_stderr = 1;
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#if SEMIHOST_V2
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char features[1];
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if (_get_semihosting_exts (features, 0, 1) > 0)
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{
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supports_ext_exit_extended
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= features[0] & (1 << SH_EXT_EXIT_EXTENDED_BITNUM);
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supports_ext_stdout_stderr
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= features[0] & (1 << SH_EXT_STDOUT_STDERR_BITNUM);
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}
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#endif
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}
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int
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_get_semihosting_exts (char* features, int offset, int num)
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{
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int len;
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struct fdent *pfd;
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int fd = _open (":semihosting-features", O_RDONLY);
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memset (features, 0, num);
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if (fd == -1)
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{
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return -1;
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}
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pfd = findslot (fd);
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#ifdef ARM_RDI_MONITOR
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len = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
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#else
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asm ("mov r0,%2; swi %a1; mov %0, r0"
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: "=r"(len)
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: "i" (SWI_Flen),"r"(pfd->handle)
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: "r0");
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#endif
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if (len < NUM_SHFB_MAGIC
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|| num > (len - NUM_SHFB_MAGIC))
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{
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_close (fd);
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return -1;
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}
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char buffer[NUM_SHFB_MAGIC];
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int n_read = _read (fd, buffer, NUM_SHFB_MAGIC);
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if (n_read < NUM_SHFB_MAGIC
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|| buffer[0] != SHFB_MAGIC_0
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|| buffer[1] != SHFB_MAGIC_1
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|| buffer[2] != SHFB_MAGIC_2
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|| buffer[3] != SHFB_MAGIC_3)
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{
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_close (fd);
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return -1;
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}
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if (_lseek (fd, offset, SEEK_CUR) < 0)
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{
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_close (fd);
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return -1;
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}
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n_read = _read (fd, features, num);
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_close (fd);
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return checkerror (n_read);
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}
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static int
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