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Fleshing out ez8 context switch logic

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@684 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2008-02-14 20:53:15 +00:00
parent f91e90672e
commit 84d1884e33
10 changed files with 734 additions and 27 deletions
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40
arch/README.txt
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@ -123,13 +123,13 @@ src/Makefile
Supported Architectures
^^^^^^^^^^^^^^^^^^^^^^^
arch/sim
arch/sim - Linux simulation
A user-mode port of NuttX to the x86 Linux platform is available.
The purpose of this port is primarily to support OS feature development.
This port does not support interrupts or a real timer (and hence no
round robin scheduler) Otherwise, it is complete.
arch/arm
arch/arm - ARM-based micro-controllers
This directory holds common ARM architectures. At present, this includes
the following subdirectories:
@ -156,18 +156,36 @@ arch/m68322
A work in progress.
STATUS: Stalled for the moment.
arch/pjrc-8051
arch/pjrc-8051 - 8051/52 microcontrollers
8051 Microcontroller. This port is not quite ready for prime time.
arch/z16
ZiLOG z16f Microcontroller.
STATUS: Released in nuttx-0.3.7. Fully functional other than issues
addressed in ${TOPDIR}/TODO.
arch/z16 - ZiLOG 16-bit processors
This directory holds related, 16-bit architectures from ZiLOG. At
present, this includes the following subdirectories:
arch/z80
ZiLOG z80 Microcontroller.
STATUS: Functional with no known defects. There are still several
OS features that have not yet been tested (e.g., networking).
arch/z16/include and arch/z16/common
Common microcontroller logic.
arch/z16/include/z16f and arch/z16/src/z16f
ZiLOG z16f Microcontroller.
STATUS: Released in nuttx-0.3.7. Fully functional other than issues
addressed in ${TOPDIR}/TODO.
arch/z80 - ZiLOG 8-bit microcontrollers
This directory holds related, 8-bit architectures from ZiLOG. At
present, this includes the following subdirectories:
arch/z80/include and arch/z80/common
Common microcontroller logic.
arch/z80/include/z80 and arch/z80/src/z80
Classic ZiLOG z80 Microcontroller.
STATUS: Functional with no known defects. There are still several
OS features that have not yet been tested (e.g., networking).
arch/z80/include/z8 and arch/z80/src/z8
ZiLOG Z8Encore! Microcontroller
This is a work in progress.
The following architecture directories are deprecated. They have been
replaced by the logic in arm/arm and will deleted at some point in the

23
arch/z80/include/z8/irq.h
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@ -236,11 +236,12 @@
#define XCPT_RR10 (5)
#define XCPT_RR12 (6)
#define XCPT_R1R4 (7)
#define XCPT_SP (8) /* Index 8: SP[8:15] */
#define XCPT_I (9) /* Index 9: FLAGS */
#define XCPT_PC (10) /* Index 10: PC[8:15] */
#define XCPT_IRQCTL (8) /* Index 8: IRQCTL register */
#define XCPT_SP (9) /* Index 9: SP[8:15] */
#define XCPT_RPFLAGS (10) /* Index 10: RP (MS) and FLAGS (LS) */
#define XCPT_PC (11) /* Index 11: PC[8:15] */
#define XCPTCONTEXT_REGS (11)
#define XCPTCONTEXT_REGS (12)
/* Byte offsets: */
@ -260,12 +261,14 @@
#define XCPT_R13_OFFS (2*XCPT_RR12+1)
#define XCPT_R14_OFFS (2*XCPT_R1R4)
#define XCPT_R15_OFFS (2*XCPT_R1R4+1)
#define XCPT_SPH_OFFS (2*XCPT_SP) /* Offset 16: SP[8:15] */
#define XCPT_SPL_OFFS (2*XCPT_SP+1) /* Offset 17: SP[0:7] */
#define XCPT_RP_OFFS (2*XCPT_I) /* Offset 18: Register pointer */
#define XCPT_FLAGS_OFFS (2*XCPT_I+1) /* Offset 19: FLAGS */
#define XCPT_PCH_OFFS (2*XCPT_PC) /* Offset 20: PC[8:15] */
#define XCPT_PCL_OFFS (2*XCPT_PC+1) /* Offset 21: PC[0:7] */
#define XCPT_UNUSED_OFFS (2*XCPT_IRQCTL) /* Offset 16: Unused (zero) */
#define XCPT_IRQCTL_OFFS (2*XCPT_IRQCTL+1) /* offset 17: IRQCTL register */
#define XCPT_SPH_OFFS (2*XCPT_SP) /* Offset 18: SP[8:15] */
#define XCPT_SPL_OFFS (2*XCPT_SP+1) /* Offset 19: SP[0:7] */
#define XCPT_RP_OFFS (2*XCPT_I) /* Offset 20: Register pointer */
#define XCPT_FLAGS_OFFS (2*XCPT_I+1) /* Offset 21: FLAGS */
#define XCPT_PCH_OFFS (2*XCPT_PC) /* Offset 22: PC[8:15] */
#define XCPT_PCL_OFFS (2*XCPT_PC+1) /* Offset 23: PC[0:7] */
#define XCPTCONTEXT_SIZE (2*XCPTCONTEXT_REGS)

2
arch/z80/src/common/up_schedulesigaction.c
View File

@ -161,7 +161,7 @@ void up_schedule_sigaction(FAR _TCB *tcb, sig_deliver_t sigdeliver)
{
/* Set up to vector to the trampoline with interrupts disabled. */
SIGNAL_SETUP(tcb, sigdeliver, tcb->xcp.regs)
SIGNAL_SETUP(tcb, sigdeliver, tcb->xcp.regs);
}
irqrestore(flags);

4
arch/z80/src/z8/Make.defs
View File

@ -43,6 +43,6 @@ CMN_CSRCS = up_initialize.c up_allocateheap.c up_createstack.c \
up_mdelay.c up_udelay.c up_schedulesigaction.c \
up_sigdeliver.c up_usestack.c
CHIP_SSRCS = z8_vector.S #z8_saveusercontext.S z8_restoreusercontext.S
CHIP_CSRCS = #z8_initialstate.c z8_irq.c z8_copystate.c z8_registerdump.c
CHIP_SSRCS = z8_vector.S z8_saveusercontext.S z8_restorecontext.S
CHIP_CSRCS = z8_initialstate.c z8_copystate.c #z8_irq.c z8_registerdump.c

168
arch/z80/src/z8/switch.h Normal file
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@ -0,0 +1,168 @@
/************************************************************************************
* arch/z80/src/z8/switch.h
* arch/z80/src/chip/switch.h
*
* Copyright (C) 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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.
*
************************************************************************************/
#ifndef __Z80_SWITCH_H
#define __Z80_SWITCH_H
/************************************************************************************
* Included Files
************************************************************************************/
#include <sys/types.h>
#include <nuttx/sched.h>
#include <nuttx/arch.h>
#include "up_internal.h"
/************************************************************************************
* Definitions
************************************************************************************/
/* Macros for portability */
/* Initialize the IRQ state */
#define INIT_IRQCONTEXT() current_regs = NULL
/* IN_INTERRUPT returns TRUE if the system is current operating in the interrupt
* context. IN_INTERRUPT is the inline equivalent of up_interrupt_context().
*/
#define IN_INTERRUPT() (current_regs != NULL)
/* The following macro is used when the system enters interrupt handling logic */
#define IRQ_ENTER(irq, regs) current_regs = (regs)
/* The following macro is used when the system exits interrupt handling logic */
#define IRQ_LEAVE(irq) current_regs = NULL
/* The following macro is used to sample the interrupt state (as a opaque handle) */
#define IRQ_STATE() (current_regs)
/* Copy a register state save structure to another location */
#define COPYSTATE(r1,r2) z8_copystate(r1,r2)
/* Save the current IRQ context in the specified TCB */
#define SAVE_IRQCONTEXT(tcb) COPYSTATE((tcb)->xcp.regs, current_regs)
/* Set the current IRQ context to the state specified in the TCB */
#define SET_IRQCONTEXT(tcb) COPYSTATE(current_regs, (tcb)->xcp.regs)
/* Save the user context in the specified TCB. User context saves can be simpler
* because only those registers normally saved in a C called need be stored.
*/
#define SAVE_USERCONTEXT(tcb) z8_saveusercontext((tcb)->xcp.regs)
/* Restore the full context -- either a simple user state save or the full,
* IRQ state save.
*/
#define RESTORE_USERCONTEXT(tcb) z8_restorecontext((tcb)->xcp.regs)
/* Verify that we have a signal handler */
#define SIGNAL_DELIVERING(tcb) (tcb->xcp.sigdeliver != NULL)
/* Setup the signal handler trampoline */
#define SIGNAL_SETUP(tcb, sigdeliver, regs) z8_sigsetup(tcb, sigdeliver, regs)
/* Return from a signal handler using the provided register context */
#define SIGNAL_RETURN(regs) z8_restorecontext(regs)
/* Dump the current machine registers */
#define _REGISTER_DUMP() z8_registerdump()
/************************************************************************************
* Public Variables
************************************************************************************/
#ifndef __ASSEMBLY__
/* This holds a references to the current interrupt level
* register storage structure. If is non-NULL only during
* interrupt processing.
*/
extern chipreg_t *current_regs;
#endif
/************************************************************************************
* Public Function Prototypes
************************************************************************************/
#ifndef __ASSEMBLY__
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
/* Defined in z8_copystate.c */
EXTERN void z8_copystate(FAR chipreg_t *dest, FAR const chipreg_t *src);
/* Defined in z8_saveusercontext.asm */
EXTERN int z8_saveusercontext(FAR chipreg_t *regs);
/* Defined in z8_restorecontext.asm */
EXTERN int z8_restorecontext(FAR chipreg_t *regs);
/* Defined in z8_sigsetup.c */
EXTERN void z8_sigsetup(FAR _TCB *tcb, sig_deliver_t sigdeliver, FAR chipreg_t *regs);
/* Defined in z8_registerdump.c */
EXTERN void z8_registerdump(void);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif
#endif /* __Z80_SWITCH_H */

93
arch/z80/src/z8/z8_initialstate.c Normal file
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@ -0,0 +1,93 @@
/****************************************************************************
* arch/z80/src/z8/z8_initialstate.c
*
* Copyright (C) 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <string.h>
#include <nuttx/arch.h>
#include "chip/chip.h"
#include "up_internal.h"
#include "up_arch.h"
/****************************************************************************
* Private 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));
#ifndef CONFIG_SUPPRESS_INTERRUPTS
xcp->regs[XCPT_IRQCTL] = %0080; /* IRQE bit will enable interrupts */
#endif
xcp->regs[XCPT_RPFLAGS] = %e000; /* RP=%e0 */
xcp->regs[XCPT_SP] = (chipreg_t)tcb->adj_stack_ptr;
xcp->regs[XCPT_PC] = (chipreg_t)tcb->start;
}

94
arch/z80/src/z8/z8_registerdump.c Normal file
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@ -0,0 +1,94 @@
/****************************************************************************
* arch/z80/src/z8/z8_registerdump.c
*
* Copyright (C) 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <debug.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include "chip/switch.h"
#include "os_internal.h"
#include "up_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
/* Output debug info if stack dump is selected -- even if
* debug is not selected.
*/
#ifdef CONFIG_ARCH_STACKDUMP
# undef lldbg
# define lldbg lib_lowprintf
#endif
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: z80_registerdump
****************************************************************************/
#ifdef CONFIG_ARCH_STACKDUMP
static void z8_registerdump(void)
{
if (current_regs)
{
lldbg("REGS: %04x %04x %04x %04x %04x %04x %04x %04x\n",
current_regs[XCPT_RR0], current_regs[XCPT_RR2],
current_regs[XCPT_RR4], current_regs[XCPT_RR6],
current_regs[XCPT_RR8], current_regs[XCPT_RR10],
current_regs[XCPT_RR12], current_regs[XCPT_RR14]);
lldbg("SP: %04x PC: %04x IRQCTL: %02x RP: %02x FLAGS: %02x\n",
current_regs[XCPT_SP], current_regs[XCPT_PC],
current_regs[XCPT_IRQCTL] & 0xff,
current_regs[XCPT_RPFLAGS] >> 8,
current_regs[XCPT_RPFLAGS] & 0xff);
}
}
#endif

166
arch/z80/src/z8/z8_restorecontext.S Executable file
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@ -0,0 +1,166 @@
/**************************************************************************
* arch/z80/src/z8/z8_saveusercontext.S
* Save the state of the current user thread
*
* Copyright (C) 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <arch/irq.h>
#include <ez8.inc>
/**************************************************************************
* Definitions
**************************************************************************/
xdef _z8_restorecontext
/**************************************************************************
* Code
**************************************************************************/
segment CODE
/****************************************************************************
* Name: _z8_restorecontext
*
* Description:
* Restore the task context that was previously saved via
* _z8_saveusercontext() or by interrupt handling. Unlike the
* _z8_saveusercontext() counterpart, we do not know the context of the
* restored task and, hence, we must handle the worst case -- restore
* everythihng.
*
* Parameters:
* On entry, the following stack organization is assumed:
*
* Pointer to the context save structure
* TOS -> Return address (2)
*
* Assumptions:
* Large model, dynamic frames
*
**************************************************************************/
_z8_restorecontext:
/* Disable all interrupts because we are going to be using
* the IRQ register set.
*/
di
/* Switch to IRQ register set */
srp #%f0
/* Get the rr0 = the current value of the stack pointer */
ldx r0, sph /* rr0 = stack pointer */
ldx r1, spl
/* Get rr6 = the pointer to the context save structure */
ldx r6, 2(rr0) /* rr6 = pointer to context structure */
ldx r7, 3(rr0)
/* Copy all registers into the user register area. NOTE: we
* should use the saved RP value to determine the destination
* address
*/
ld r1, #%e0 /* r1 = destination address */
ld r2, r6 /* rr2 = source address */
ld r3, r7
ld r4, #16 /* r4 = number of bytes to copy */
cp r2, #0
jr z, _z8_restore2
_z8_restore1:
ldx r0, @rr2
ld @r1, r0
inc r1
incw rr2
djnz r4, _z8_restore1
/* Set the new stack pointer */
_z8_restore2:
ldx r0, XCPT_SPH_OFFS(rr6)
ldx r1, XCPT_SPL_OFFS(rr6)
ldx sph, r0
ldx spl, r1
/* Push the return address onto the stack */
ldx r0, XCPT_PCH_OFFS(rr6)
ldx r1, XCPT_PCL_OFFS(rr6)
push r1
push r0
/* Recover the flags settings.. but don't restore the flags yet */
ldx r1, XCPT_FLAGS_OFFS(rr6)
/* Determine whether interrupts must be enabled on return. This
* would be nicer to do below, but later we will need to preserve
* the condition codes in the flags.
*/
ldx r0, XCPT_IRQCTL_OFFS(rr6)
tm r0, #%80
jr nz, _z8_returnenabled
/* Restore the flag settings */
ldx flags, r1
/* Restore the user register page and return with interrupts disabled */
srp #%e0 /* Does not effect flags */
ret /* Does not effect flags */
_z8_returnenabled:
/* Restore the flag settings */
ldx flags, r1
/* Restore the user register page, re-enable interrupts and return */
srp #%e0 /* Does not effect flags */
ei /* Does not effect flags */
ret /* Does not effect flags */
end

165
arch/z80/src/z8/z8_saveusercontext.S Executable file
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@ -0,0 +1,165 @@
/**************************************************************************
* arch/z80/src/z8/z8_saveusercontext.S
* Save the state of the current user thread
*
* Copyright (C) 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <arch/irq.h>
#include <ez8.inc>
/**************************************************************************
* Definitions
**************************************************************************/
xdef _z8_saveusercontext
/**************************************************************************
* Code
**************************************************************************/
segment CODE
/****************************************************************************
* Name: _z8_saveusercontext
*
* Description:
* Save the current state of the user thread. Since this function is
* called from user code, it is only necessary to save the parts of the
* context that must be preserved between function calls. This includes
*
* - Frame pointer (r14, r15)
* - Register pointer (RP)
* - Interrupt state (flags)
* - Stack pointer (sph, spl)
* - Return address
*
* Parameters:
* On entry, the following stack organization is assumed:
*
* Pointer to the context save structure
* TOS -> Return address (2)
*
* Assumptions:
* Large model, dynamic frames
*
**************************************************************************/
_z8_saveusercontext:
/* Get the rr6 = the current value of the stack pointer */
ldx r6, sph /* rr6 = stack pointer */
ldx r7, spl
/* Get rr2 = the pointer to the context save structure */
ldx r2, 2(rr6) /* rr2 = pointer to context structure */
ldx r3, 3(rr6)
/* Get the value currently in the interrupt control register.
* Bit 7 (IRQE) determines whether or not interrupts are
* currently enabled (0:disabled, 1:enabled)
*/
ldx r4, IRQCTL /* r4 = IRQCTL value */
/* Disable all interrupts so that there can be no concurrent
* modification of the TCB state save area.
*/
di
/* Fetch and save the return address from the stack */
ldx r0, @rr6 /* rr0 = return address */
ldx r1, 1(rr6)
ldx XCPT_PCH_OFFS(rr2), r0
ldx XCPT_PCL_OFFS(rr2), r1
/* Fetch and save the register pointer */
ldx r0, rp /* r0 = register pointer */
ldx XCPT_RP_OFFS(rr2), r0
/* Calculate the value of the stack pointer on return
* from this function
*/
ld r1, #3 /* rr0 = 3 */
clr r0
add r1, r7 /* rr0 = SP + 3 */
adc r0, r6
ldx XCPT_SPH_OFFS(rr2), r0
ldx XCPT_SPL_OFFS(rr2), r1
/* Save the IRQCTL register value */
clr r0
ldx XCPT_UNUSED_OFFS(rr2), r0
ldx XCPT_IRQCTL_OFFS(rr2), r4
/* Save the frame pointer (rr14) in the context structure */
ldx XCPT_R14_OFFS(rr2), r14
ldx XCPT_R15_OFFS(rr2), r15
/* Set the return value of 1 in the context structure. When the
* state is restored (via z8_restorecontext() or an interrupt
* return), the return value of 1 distinguishes the no-context-
* switch case.
*/
/* clr r0 */
ld r1, #1
ldx XCPT_R0_OFFS(rr2), r0
ldx XCPT_R1_OFFS(rr2), r1
/* Setup to return zero for the no-context-switch case */
/* clr r0 */
clr r1
/* Now decide if we need to re-enable interrupts or not */
tm r4, #%80
jr z, _z8_noenable
ei
_z8_noenable:
ret
end

6
arch/z80/src/z80/z80_initialstate.c
View File

@ -1,5 +1,5 @@
/****************************************************************************
* arch/z80/src/z80/up_initialstate.c
* arch/z80/src/z80/z80_initialstate.c
*
* Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
@ -87,6 +87,6 @@ void up_initial_state(_TCB *tcb)
#ifndef CONFIG_SUPPRESS_INTERRUPTS
xcp->regs[XCPT_I] = Z80_C_FLAG; /* Carry flag will enable interrupts */
#endif
xcp->regs[XCPT_SP] = (uint16)tcb->adj_stack_ptr;
xcp->regs[XCPT_PC] = (uint16)tcb->start;
xcp->regs[XCPT_SP] = (chipreg_t)tcb->adj_stack_ptr;
xcp->regs[XCPT_PC] = (chipreg_t)tcb->start;
}