diff options
Diffstat (limited to 'nuttx/arch/arm/src/armv7-m/up_initialstate.c')
-rw-r--r-- | nuttx/arch/arm/src/armv7-m/up_initialstate.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/armv7-m/up_initialstate.c b/nuttx/arch/arm/src/armv7-m/up_initialstate.c new file mode 100644 index 000000000..52a2682a0 --- /dev/null +++ b/nuttx/arch/arm/src/armv7-m/up_initialstate.c @@ -0,0 +1,200 @@ +/**************************************************************************** + * arch/arm/src/armv7-m/up_initialstate.c + * + * Copyright (C) 2009, 2011-2 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <sys/types.h> +#include <stdint.h> +#include <string.h> + +#include <nuttx/arch.h> + +#include "up_internal.h" +#include "up_arch.h" + +#include "psr.h" +#include "exc_return.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: up_initial_state + * + * Description: + * A new thread is being started and a new TCB + * has been created. This function is called to initialize + * the processor specific portions of the new TCB. + * + * This function must setup the intial architecture registers + * and/or stack so that execution will begin at tcb->start + * on the next context switch. + * + ****************************************************************************/ + +void up_initial_state(_TCB *tcb) +{ + struct xcptcontext *xcp = &tcb->xcp; + + /* Initialize the initial exception register context structure */ + + memset(xcp, 0, sizeof(struct xcptcontext)); + + /* Save the initial stack pointer */ + + xcp->regs[REG_SP] = (uint32_t)tcb->adj_stack_ptr; + + /* Set the stack limit value */ + + xcp->regs[REG_R10] = (uint32_t)tcb->stack_alloc_ptr + 64; + + /* Fill the stack with a watermark value */ + + memset(tcb->stack_alloc_ptr, 0xff, tcb->adj_stack_size); + + /* Save the task entry point (stripping off the thumb bit) */ + + xcp->regs[REG_PC] = (uint32_t)tcb->start & ~1; + + /* Specify thumb mode */ + + xcp->regs[REG_XPSR] = ARMV7M_XPSR_T; + + /* If this task is running PIC, then set the PIC base register to the + * address of the allocated D-Space region. + */ + +#ifdef CONFIG_PIC + if (tcb->dspace != NULL) + { + /* Set the PIC base register (probably R10) to the address of the + * alloacated D-Space region. + */ + + xcp->regs[REG_PIC] = (uint32_t)tcb->dspace->region; + } + + /* Make certain that bit 0 is set in the main entry address. This + * is only an issue when NXFLAT is enabled. NXFLAT doesn't know + * anything about thumb; the addresses that NXFLAT sets are based + * on file header info and won't have bit 0 set. + */ + +#ifdef CONFIG_NXFLAT + tcb->entry.main = (main_t)((uint32_t)tcb->entry.main | 1); +#endif +#endif /* CONFIG_PIC */ + +#ifdef CONFIG_ARMV7M_CMNVECTOR + /* Set privileged- or unprivileged-mode, depending on how NuttX is + * configured and what kind of thread is being started. + * + * If the kernel build is not selected, then all threads run in + * privileged thread mode. + * + * If FPU support is not configured, set the bit that indicates that + * the context does not include the volatile FP registers. + */ + + xcp->regs[REG_EXC_RETURN] = EXC_RETURN_BASE | EXC_RETURN_THREAD_MODE; + +#ifndef CONFIG_ARCH_FPU + + xcp->regs[REG_EXC_RETURN] |= EXC_RETURN_STD_CONTEXT; + +#else + + xcp->regs[REG_FPSCR] = 0; // XXX initial FPSCR should be configurable + xcp->regs[REG_FPReserved] = 0; + +#endif + +#ifdef CONFIG_NUTTX_KERNEL + if ((tcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_KERNEL) + { + /* It is a normal task or a pthread. Set user mode */ + + xcp->regs[REG_EXC_RETURN] = EXC_RETURN_PROCESS_STACK; + } +#endif + +#else /* CONFIG_ARMV7M_CMNVECTOR */ + + /* Set privileged- or unprivileged-mode, depending on how NuttX is + * configured and what kind of thread is being started. + * + * If the kernel build is not selected, then all threads run in + * privileged thread mode. + */ + +#ifdef CONFIG_NUTTX_KERNEL + if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_KERNEL) + { + /* It is a kernel thread.. set privileged thread mode */ + + xcp->regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; + } + else + { + /* It is a normal task or a pthread. Set user mode */ + + xcp->regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; + } +#endif +#endif /* CONFIG_ARMV7M_CMNVECTOR */ + + /* Enable or disable interrupts, based on user configuration */ + +#ifdef CONFIG_SUPPRESS_INTERRUPTS + xcp->regs[REG_PRIMASK] = 1; +#endif +} |