[PATCH v2 14/30] bsd-user/arm/target_arch_thread.h: Routines to create and switch to a thread

[Warner Losh <imp@bsdimp.com>]

Implement target_thread_init (to create a thread) and target_set_upcall
(to switch to a thread) for arm.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Kyle Evans <kevans@FreeBSD.org>
---
 bsd-user/arm/target_arch_thread.h | 80 +++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 bsd-user/arm/target_arch_thread.h

diff --git a/bsd-user/arm/target_arch_thread.h b/bsd-user/arm/target_arch_thread.h
new file mode 100644
index 0000000000..ae5b0d6c38
--- /dev/null
+++ b/bsd-user/arm/target_arch_thread.h
@@ -0,0 +1,80 @@
+/*
+ *  arm thread support
+ *
+ *  Copyright (c) 2013 Stacey D. Son
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef _TARGET_ARCH_THREAD_H_
+#define _TARGET_ARCH_THREAD_H_
+
+/* Compare to arm/arm/vm_machdep.c cpu_set_upcall_kse() */
+static inline void target_thread_set_upcall(CPUARMState *env, abi_ulong entry,
+    abi_ulong arg, abi_ulong stack_base, abi_ulong stack_size)
+{
+    abi_ulong sp;
+
+    /*
+     * Make sure the stack is properly aligned.
+     * arm/include/param.h (STACKLIGN() macro)
+     */
+    sp = (u_int)(stack_base + stack_size) & ~0x7;
+
+    /* sp = stack base */
+    env->regs[13] = sp;
+    /* pc = start function entry */
+    env->regs[15] = entry & 0xfffffffe;
+    /* r0 = arg */
+    env->regs[0] = arg;
+    env->spsr = ARM_CPU_MODE_USR;
+    /*
+     * Thumb mode is encoded by the low bit in the entry point (since ARM can't
+     * execute at odd addresses). When it's set, set the Thumb bit (T) in the
+     * CPSR.
+     */
+    if (entry & 0x1) {
+        cpsr_write(env, cpsr_read(env) | CPSR_T, CPSR_T, CPSRWriteByInstr);
+    }
+}
+
+static inline void target_thread_init(struct target_pt_regs *regs,
+        struct image_info *infop)
+{
+    abi_long stack = infop->start_stack;
+    memset(regs, 0, sizeof(*regs));
+    regs->ARM_cpsr = 0x10;
+    /*
+     * Thumb mode is encoded by the low bit in the entry point (since ARM can't
+     * execute at odd addresses). When it's set, set the Thumb bit (T) in the
+     * CPSR.
+     */
+    if (infop->entry & 1) {
+        regs->ARM_cpsr |= CPSR_T;
+    }
+    regs->ARM_pc = infop->entry & 0xfffffffe;
+    regs->ARM_sp = infop->start_stack;
+    if (bsd_type == target_freebsd) {
+        regs->ARM_lr = infop->entry & 0xfffffffe;
+    }
+    /* FIXME - what to for failure of get_user()? */
+    get_user_ual(regs->ARM_r2, stack + 8); /* envp */
+    get_user_ual(regs->ARM_r1, stack + 4); /* envp */
+    /* XXX: it seems that r0 is zeroed after ! */
+    regs->ARM_r0 = 0;
+    /* For uClinux PIC binaries.  */
+    /* XXX: Linux does this only on ARM with no MMU (do we care ?) */
+    regs->ARM_r10 = infop->start_data;
+}
+
+#endif /* !_TARGET_ARCH_THREAD_H_ */
-- 
2.33.0