Chris Zankel writes:

The following patches add support for the Xtensa processor architecture
to uClibc. They are based on a recent SVN checkout (12/05/2007).

The first patch (attached to this post) adds Xtensa support to various
shared configuration and make files. The following patches then include
the Xtensa specific files and directories.

I welcome any feedback and would appreciate it if you could include the
patches into the mainline tree. I am certainly committed to maintain the port. 

Bob Wilson was kind enough to review the patches.

Some notes about the architecture: Xtensa is a configurable and
extensible processor architecture developed by Tensilica. For more
information, please visit: www.linux-xtensa.org.

3 files changed, 326 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/xtensa/sys/procfs.h b/libc/sysdeps/linux/xtensa/sys/procfs.h
new file mode 100644
index 000000000..785c400c8
--- /dev/null
+++ b/libc/sysdeps/linux/xtensa/sys/procfs.h
@@ -0,0 +1,121 @@
+/* Copyright (C) 1996, 1997, 1999, 2007 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+#ifndef _SYS_PROCFS_H
+#define _SYS_PROCFS_H	1
+
+/* This is somewhat modelled after the file of the same name on SVR4
+   systems.  It provides a definition of the core file format for ELF
+   used on Linux.  It doesn't have anything to do with the /proc file
+   system, even though Linux has one.
+
+   Anyway, the whole purpose of this file is for GDB and GDB only.
+   Don't read too much into it.  Don't use it for anything other than
+   GDB unless you know what you are doing.  */
+
+#include <features.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/user.h>
+
+__BEGIN_DECLS
+
+/* Type for a general-purpose register.  */
+typedef unsigned long elf_greg_t;
+
+#define ELF_NGREG 32
+typedef elf_greg_t elf_gregset_t[ELF_NGREG];
+
+/* Register set for the floating-point registers.  */
+#define ELF_NFPREG 18
+typedef unsigned long elf_fpreg_t;
+typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
+
+/* Signal info.  */
+struct elf_siginfo
+  {
+    int si_signo;			/* Signal number.  */
+    int si_code;			/* Extra code.  */
+    int si_errno;			/* Errno.  */
+  };
+
+/* Definitions to generate Intel SVR4-like core files.  These mostly
+   have the same names as the SVR4 types with "elf_" tacked on the
+   front to prevent clashes with Linux definitions, and the typedef
+   forms have been avoided.  This is mostly like the SVR4 structure,
+   but more Linuxy, with things that Linux does not support and which
+   GDB doesn't really use excluded.  */
+
+struct elf_prstatus
+  {
+    struct elf_siginfo pr_info;		/* Info associated with signal.  */
+    short int pr_cursig;		/* Current signal.  */
+    unsigned long int pr_sigpend;	/* Set of pending signals.  */
+    unsigned long int pr_sighold;	/* Set of held signals.  */
+    __pid_t pr_pid;
+    __pid_t pr_ppid;
+    __pid_t pr_pgrp;
+    __pid_t pr_sid;
+    struct timeval pr_utime;		/* User time.  */
+    struct timeval pr_stime;		/* System time.  */
+    struct timeval pr_cutime;		/* Cumulative user time.  */
+    struct timeval pr_cstime;		/* Cumulative system time.  */
+    elf_gregset_t pr_reg;		/* GP registers.  */
+    int pr_fpvalid;			/* True if math copro being used.  */
+  };
+
+
+#define ELF_PRARGSZ     (80)    /* Number of chars for args.  */
+
+struct elf_prpsinfo
+  {
+    char pr_state;			/* Numeric process state.  */
+    char pr_sname;			/* Char for pr_state.  */
+    char pr_zomb;			/* Zombie.  */
+    char pr_nice;			/* Nice val.  */
+    unsigned long int pr_flag;		/* Flags.  */
+    unsigned short int pr_uid;
+    unsigned short int pr_gid;
+    int pr_pid, pr_ppid, pr_pgrp, pr_sid;
+    /* Lots missing */
+    char pr_fname[16];			/* Filename of executable.  */
+    char pr_psargs[ELF_PRARGSZ];	/* Initial part of arg list.  */
+  };
+
+/* The rest of this file provides the types for emulation of the
+   Solaris <proc_service.h> interfaces that should be implemented by
+   users of libthread_db.  */
+
+/* Addresses.  */
+typedef void *psaddr_t;
+
+/* Register sets.  Linux has different names.  */
+typedef elf_gregset_t prgregset_t;
+typedef elf_fpregset_t prfpregset_t;
+
+/* We don't have any differences between processes and threads,
+   therefore have only one PID type.  */
+typedef __pid_t lwpid_t;
+
+/* Process status and info.  In the end we do provide typedefs for them.  */
+typedef struct elf_prstatus prstatus_t;
+typedef struct elf_prpsinfo prpsinfo_t;
+
+__END_DECLS
+
+#endif	/* sys/procfs.h */
diff --git a/libc/sysdeps/linux/xtensa/sys/ptrace.h b/libc/sysdeps/linux/xtensa/sys/ptrace.h
new file mode 100644
index 000000000..7aad929bb
--- /dev/null
+++ b/libc/sysdeps/linux/xtensa/sys/ptrace.h
@@ -0,0 +1,156 @@
+/* `ptrace' debugger support interface.  Linux version.
+   Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007
+   Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+#ifndef _SYS_PTRACE_H
+#define _SYS_PTRACE_H	1
+
+#include <features.h>
+
+/* Kludge away careless namespace pollution from the kernel. */
+
+#undef PTRACE_GETREGS
+#undef PTRACE_SETREGS
+#undef PTRACE_GETFPREGS
+#undef PTRACE_SETFPREGS
+#undef PTRACE_GETFPREGSIZE
+
+
+__BEGIN_DECLS
+
+/* Type of the REQUEST argument to `ptrace.'  */
+enum __ptrace_request
+{
+  /* Indicate that the process making this request should be traced.
+     All signals received by this process can be intercepted by its
+     parent, and its parent can use the other `ptrace' requests.  */
+  PTRACE_TRACEME = 0,
+#define PT_TRACE_ME PTRACE_TRACEME
+
+  /* Return the word in the process's text space at address ADDR.  */
+  PTRACE_PEEKTEXT = 1,
+#define PT_READ_I PTRACE_PEEKTEXT
+
+  /* Return the word in the process's data space at address ADDR.  */
+  PTRACE_PEEKDATA = 2,
+#define PT_READ_D PTRACE_PEEKDATA
+
+  /* Return the word in the process's user area at offset ADDR.  */
+  PTRACE_PEEKUSER = 3,
+#define PT_READ_U PTRACE_PEEKUSER
+
+  /* Write the word DATA into the process's text space at address ADDR.  */
+  PTRACE_POKETEXT = 4,
+#define PT_WRITE_I PTRACE_POKETEXT
+
+  /* Write the word DATA into the process's data space at address ADDR.  */
+  PTRACE_POKEDATA = 5,
+#define PT_WRITE_D PTRACE_POKEDATA
+
+  /* Write the word DATA into the process's user area at offset ADDR.  */
+  PTRACE_POKEUSER = 6,
+#define PT_WRITE_U PTRACE_POKEUSER
+
+  /* Continue the process.  */
+  PTRACE_CONT = 7,
+#define PT_CONTINUE PTRACE_CONT
+
+  /* Kill the process.  */
+  PTRACE_KILL = 8,
+#define PT_KILL PTRACE_KILL
+
+  /* Single step the process.
+     This is not supported on all machines.  */
+  PTRACE_SINGLESTEP = 9,
+#define PT_STEP PTRACE_SINGLESTEP
+
+  /* Get all general purpose registers used by a processes.
+     This is not supported on all machines.  */
+   PTRACE_GETREGS = 12,
+#define PT_GETREGS PTRACE_GETREGS
+
+  /* Set all general purpose registers used by a processes.
+     This is not supported on all machines.  */
+   PTRACE_SETREGS = 13,
+#define PT_SETREGS PTRACE_SETREGS
+
+  /* Get all floating point registers used by a processes.
+     This is not supported on all machines.  */
+   PTRACE_GETFPREGS = 14,
+#define PT_GETFPREGS PTRACE_GETFPREGS
+
+  /* Set all floating point registers used by a processes.
+     This is not supported on all machines.  */
+   PTRACE_SETFPREGS = 15,
+#define PT_SETFPREGS PTRACE_SETFPREGS
+
+  /* Attach to a process that is already running. */
+  PTRACE_ATTACH = 16,
+#define PT_ATTACH PTRACE_ATTACH
+
+  /* Detach from a process attached to with PTRACE_ATTACH.  */
+  PTRACE_DETACH = 17,
+#define PT_DETACH PTRACE_DETACH
+
+  /* Get size required for the buffer holding the floating point registers.
+     This is not supported on all machines.  */
+   PTRACE_GETFPREGSIZE = 18,
+#define PT_GETFPREGSIZE PTRACE_GETFPREGSIZE
+
+  /* Continue and stop at the next (return from) syscall.  */
+  PTRACE_SYSCALL = 24
+#define PT_SYSCALL PTRACE_SYSCALL
+};
+
+/* Options set using PTRACE_SETOPTIONS.  */
+enum __ptrace_setoptions {
+  PTRACE_O_TRACESYSGOOD	= 0x00000001,
+  PTRACE_O_TRACEFORK	= 0x00000002,
+  PTRACE_O_TRACEVFORK   = 0x00000004,
+  PTRACE_O_TRACECLONE	= 0x00000008,
+  PTRACE_O_TRACEEXEC	= 0x00000010,
+  PTRACE_O_TRACEVFORKDONE = 0x00000020,
+  PTRACE_O_TRACEEXIT	= 0x00000040,
+  PTRACE_O_MASK		= 0x0000007f
+};
+
+/* Wait extended result codes for the above trace options.  */
+enum __ptrace_eventcodes {
+  PTRACE_EVENT_FORK	= 1,
+  PTRACE_EVENT_VFORK	= 2,
+  PTRACE_EVENT_CLONE	= 3,
+  PTRACE_EVENT_EXEC	= 4,
+  PTRACE_EVENT_VFORK_DONE = 5,
+  PTRACE_EVENT_EXIT	= 6
+};
+
+/* Perform process tracing functions.  REQUEST is one of the values
+   above, and determines the action to be taken.
+   For all requests except PTRACE_TRACEME, PID specifies the process to be
+   traced.
+
+   PID and the other arguments described above for the various requests should
+   appear (those that are used for the particular request) as:
+     pid_t PID, void *ADDR, int DATA, void *ADDR2
+   after REQUEST.  */
+extern long int ptrace (enum __ptrace_request __request, ...) __THROW;
+
+__END_DECLS
+
+#endif /* _SYS_PTRACE_H */
diff --git a/libc/sysdeps/linux/xtensa/sys/ucontext.h b/libc/sysdeps/linux/xtensa/sys/ucontext.h
new file mode 100644
index 000000000..4c37201ea
--- /dev/null
+++ b/libc/sysdeps/linux/xtensa/sys/ucontext.h
@@ -0,0 +1,49 @@
+/* Copyright (C) 2001, 2006, 2007  Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+#ifndef _SYS_UCONTEXT_H
+#define _SYS_UCONTEXT_H	1
+
+#include <features.h>
+#include <signal.h>
+
+/* We need the signal context definitions even if they are not used
+   included in <signal.h>.  */
+#include <bits/sigcontext.h>
+
+/* Revise this structure when we add support for coprocessors.  */
+
+/* Structure to describe FPU registers.  */
+typedef struct fpregset
+{
+  int dummy;
+} fpregset_t;
+
+typedef struct sigcontext mcontext_t;
+
+/* Userlevel context.  */
+typedef struct ucontext
+  {
+    unsigned long int uc_flags;
+    struct ucontext *uc_link;
+    stack_t uc_stack;
+    mcontext_t uc_mcontext;
+    __sigset_t uc_sigmask;
+  } ucontext_t;
+
+#endif /* sys/ucontext.h */