/************************************************************************************
* arch/sh/src/m16c/m16c_head.S
*
* Copyright (C) 2009 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 "chip.h"
#include "up_internal.h"
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
/************************************************************************************
* Macro Definitions
************************************************************************************/
/*****************************************************************************
* Name: showprogress
*
* Description:
* Print a character on the UART to show boot status.
*
*****************************************************************************/
.macro showprogress, code
#ifdef CONFIG_DEBUG
.globl _up_lowputc
mov.b r#\code1l /* Character to print */
jsr.a _up_lowputc /* Print it */
#endif
.endm
/************************************************************************************
* Data
************************************************************************************/
/* The near RAM memory map is as follows:
*
* 0x00400 - DATA Size: Determined by linker
* BSS Size: Determined by linker
* Interrupt stack Size: CONFIG_ARCH_INTERRUPTSTACK
* Idle stack Size: CONFIG_IDLETHREAD_STACKSIZE
* Heap Size: Everything remaining
* 0x00bff - (end+1)
*/
.section .rodata
.globl _g_snbss
.type _g_snbss, object
_g_snbss:
.word _g_snbss
.size _g_snbss, .-_g_snbss
.globl _g_enbss
.type _g_enbss, object
_g_enbss:
.word _g_enbss
.size _g_enbss, .-_g_enbss
.globl _g_sndata
.type _g_sndata, object
_g_sndata:
.word _g_sndata
.size _g_sndata, .-_g_sndata
.globl _g_endata
.type _g_endata, object
_g_endata:
.word _g_endata
.size _g_endata, .-_g_endata
.globl _g_enronly
.type _g_enronly, object
_g_enronly:
.long _g_enronly
.size _g_enronly, .-_g_efronly
#ifdef CONFIG_M16C_HAVEFARRAM
.globl _g_sfbss
.type _g_sfbss, object
_g_sfbss:
.long _g_sfbss
.size _g_sfbss, .-_g_sfbss
.globl _g_efbss
.type _g_efbss, object
_g_efbss:
.long _g_efbss
.size _g_efbss, .-_g_efbss
.globl _g_sfdata
.type _g_sfdata, object
_g_sfdata:
.long _g_sfdata
.size _g_sfdata, .-_g_sfdata
.globl _g_efdata
.type _g_efdata, object
_g_efdata:
.long _g_efdata
.size _g_efdata, .-_g_efdata
.globl _g_efronly
.type _g_efronly, object
_g_efronly:
.long _g_efronly
.size _g_efronly, .-_g_efronly
#endif
.globl _g_svarvect
.type _g_svarvect, object
_g_svarvect:
.long _svarvect
.size _g_svarvect, .-_g_svarvect
.globl _g_heapbase
.type _g_heapbase, object
_g_heapbase:
.long _enbss+CONFIG_ARCH_INTERRUPTSTACK+CONFIG_IDLETHREAD_STACKSIZE
.size _g_heapbase, .-_g_heapbase
/************************************************************************************
* Code
************************************************************************************/
/************************************************************************************
* Name: _start
*
* Description:
* After reset, program execution starts here.
*
************************************************************************************/
.text
.globl __start
.globl _enbss
.type __start, #function
__start:
/* Set the interrupt and user stack pointers */
mov.w #_enbss, R0
ldc R0, isp /* Set the interrupt stack pointer to the end of BSS */
add.w #CONFIG_IDLETHREAD_STACKSIZE, R0
fset U /* Set bit 7 (U) to select the user stack pointer */
ldc R0, sp /* Set the user stack pointer */
/* Set BCLK speed. At reset, the processor clock (BLCK) defaults to a divisor of 8.
* This sets clock to F1 (divide by 1) on XIN: BCLK = XIN frequency.
*/
mov.b #0x01, M16C_PRCR /* Unprotect CM0 to change clock setting */
mov.b #0x08, M16C_CM0 /* enable CM17 and CM16 to set BCLK to F1
* CM17 & CM16 defaults to 0 after reset and
* so we only need to reset CM06 to 0 */
mov.b #0x00,M16C_PRCR /* protect CM0 */
/* The two MS bits of the interrupt cause select register must be set to
* enable the use of INT4 and INT5
*/
mov.b #0xc0, M16C_IFSR /* Set b7 & b6 if application will use INT4 & INT5 */
ldc #M16C_IRAM_BASE, sb /* Set sb register (to what?) */
/* Set up INTB to point to location of variable vector table */
mov.w _g_svarvect, r0 /* R0 = lower 16-bits */
mov.w _g_svarvect+2, r1 /* R1 = upper 4-bits */
ldc r1, intbh
ldc r0, intbl
/* Configure the uart so that we can get debug output as soon as possible. */
.globl _up_lowsetup /* Early initialization of UART */
jsr.a _up_lowsetup
showprogress 'A'
/* Clear near .bss sections */
mov.b #0x00, r0l /* r0l: 0 */
mov.w _g_snbss, a1 /* a1: start of near .bss */
mov.w _g_enbss, r3 /* r3: end of near .bss */
sub.w a1, r3 /* r3: size of near .bss */
sstr.b /* Clear near .bss */
/* Clear far .bss sections */
showprogress 'B'
#ifdef CONFIG_M16C_HAVEFARRAM
# warning "Far RAM support not implemented"
#endif
/* Initialize near .data sections (.rodata is not moved) */
mov.w _g_enronly, a0 /* a0: Low 16 bits of source address */
mov.b _g_enronly+2, r1h /* 4 MS of 20-bit source address */
mov.w _g_sndata, a1 /* a1: start of near .data */
mov.w _g_endata, r3 /* r3: end of near .data */
sub.w a1, r3 /* r3: size of near .data */
smovf.b /* Copy source to near .data */
/* Initialize far .data sections (.rodata is not moved) */
showprogress 'C'
#ifdef CONFIG_M16C_HAVEFARRAM
# warning "Far RAM support not implemented"
#endif
/* Perform early console initialization */
#ifdef CONFIG_USE_EARLYSERIALINIT
.globl _up_earlyconsoleinit /* Early initialization of console driver */
jsr.a _up_earlyconsoleinit /* Call it */
showprogress 'D'
#endif
/* Call C++ constructors */
#ifdef CONFIG_CPLUSPLUS
# warning "No C++ support yet"
showprogress 'E'
#endif
/* Initialize onboard LEDs */
#ifdef CONFIG_ARCH_LEDS
.globl _up_ledinit /* Boot LED setup */
jsr.a _up_ledinit /* Call it */
#endif
showprogress '\n'
/* Pass control to NuttX */
.globl _os_start
jsr.a _os_start
/* NuttX will not return, but just in case... */
_os_exit:
jmp.s _os_exit
.size __start, .-__start
.end
