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More init logic

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@2303 7fd9a85b-ad96-42d3-883c-3090e2eb8679
This commit is contained in:
patacongo 2009-12-03 23:08:07 +00:00
parent 33fad62ee8
commit 52268ae4b2
4 changed files with 115 additions and 28 deletions

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@ -552,7 +552,7 @@ __start:
* as possible. Modifies r0, r1, r2, and r14.
*/
bl up_lowsetup
bl up_lowsetup
showprogress 'A'
/* Setup system stack (and get the BSS range) */

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@ -53,6 +53,7 @@
************************************************************************************/
.globl __start
.globl os_start
.file "mc9s12ne64_start.S"
/****************************************************************************
@ -62,10 +63,20 @@
/* Memory map initialization */
.macro MMCINIT
movb #0, HC12_MMC_INITRG /* Set the register map position */
clr HC12_MMC_INITRG /* Set the register map position to 0x0000*/
nop
movb #32, HC12_MMC_INITRM /* Set the RAM map position */
movb #1, HC12_MMC_MISC /* MISC: EXSTR1=0 EXSTR0=0 ROMHM=0 ROMON=1 */
ldab #0x09
stab *HC12_MMC_INITEE /* Set EEPROM position to 0x0800 */
#ifdef CONFIG_HC12_SERIALMON
ldab #0x39 /* Set RAM position to 0x3800 */
#else
ldab #0x20 /* Set RAM position to 0x2000*/
#endif
stab *HC12_MMC_INITRM
ldaa #MMC_MISC_ROMON /* MISC: EXSTR1=0 EXSTR0=0 ROMHM=0 ROMON=1 */
staa *HC12_MMC_MISC
.endm
/* System clock initialization */
@ -74,35 +85,33 @@
/* Select the clock source from crystal */
movb #0, HC12_CRG_CLKSEL
movb #CRG_CRGSEL_PLLSEL, HC12_CRG_CLKSEL
clr HC12_CRG_CLKSEL
/* Set the multipler and divider and enable the PLL */
movb #0, HC12_CRG_PLLCTL
movb #15, HC12_CRG_SYNR
movb #15, HC12_CRG_REFDV
movb #(CRG_PLLCTL_CME|CRG_PLLCTL_PLLON), HC12_CRG_PLLCTL
bclr *HC12_CRG_PLLCTL #CRG_PLLCTL_PLLON
ldab #15
stab HC12_CRG_SYNR
stab HC12_CRG_REFDV
bset *HC12_CRG_PLLCTL #CRG_PLLCTL_PLLON
/* Wait for the PLL to lock on */
.Lpll_lock:
ldab HC12_CRG_CRGFLG
clra
andb #CRG_CRGFLG_LOCK
ldx #0
bne .Lpll_lock
tbne d,.Lpll_lock
brclr *HC12_CRG_CRGFLG #CRG_CRGFLG_LOCK .Lpll_lock
/* The select the PLL clock source */
/* Then select the PLL clock source */
bset HC12_CRG_CLKSEL_OFFSET, #CRG_CLKSEL_PLLSEL
bset *HC12_CRG_CLKSEL #CRG_CLKSEL_PLLSEL
.endm
/****************************************************************************
* .text
****************************************************************************/
.section nonbanked, "x"
/****************************************************************************
* Name: __start
*
@ -112,6 +121,87 @@
****************************************************************************/
__start:
MMCINIT /* Initialize the MMC */
PLLINIT /* Initialize the PLL */
/* Hardware setup */
MMCINIT /* Initialize the MMC */
PLLINIT /* Initialize the PLL */
/* Setup the stack pointer */
lds .Lstackbase
/* Clear BSS */
ldx .Lsbss /* Start of .BSS */
ldd .Lebss /* End+1 of .BSS */
.Lclearbss:
pshd
cpx 2,sp+ /* Check if all BSS has been cleared */
beq .Lbsscleared /* If so, exit the loop */
clr 0,x /* Clear this byte */
inx /* Address the next byte */
bra .Lclearbss /* And loop until all cleared */
.Lbsscleared:
/* Initialize the data section */
ldx .Lsdata /* Start of .DATA (destination) */
movw .Ledata, 0, sp /* End of .DATA (destination) */
ldy .Leronly /* Start of .DATA (source) */
.Linitdata:
cpx 0, sp /* Check if all .DATA has been initialized */
beq .Ldatainitialized /* If so, exit the loop */
ldab 0, y /* Fetch the next byte from the source */
iny /* Increment the source address */
stab 0, x /* Store the byte to the destination */
inx /* Increment the destination address */
bra .Linitdata /* And loop until all of .DATA is initialized */
.Ldatainitialized:
/* Now, start the OS */
call os_start
bra __start
/* Variables:
* _sbss is the start of the BSS region (see ld.script)
* _ebss is the end of the BSS regsion (see ld.script)
* The idle task stack starts at the end of BSS and is
* of size CONFIG_IDLETHREAD_STACKSIZE. The heap continues
* from there until the end of memory. See g_heapbase
* below.
*/
.Lsbss:
.long _sbss
.Lebss:
.long _ebss
.Lstackbase:
.hword _ebss+CONFIG_IDLETHREAD_STACKSIZE-4
.Leronly:
.long _eronly /* Where .data defaults are stored in FLASH */
.Lsdata:
.long _sdata /* Where .data needs to reside in SDRAM */
.Ledata:
.long _edata
.size __start, .-__start
/* This global variable is unsigned long g_heapbase and is
* exported from here only because of its coupling to LCO
* above.
*/
.data
.align 4
.globl g_heapbase
.type g_heapbase, object
g_heapbase:
.long _ebss+CONFIG_IDLETHREAD_STACKSIZE
.size g_heapbase, .-g_heapbase
.end
.end

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@ -64,7 +64,7 @@
* Vectors
************************************************************************************/
.section .vectors, "rd"
.section .vectors, "x"
.align 2
.globl hc12_vectors
.type hc12_vectors, function

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@ -33,17 +33,14 @@
*
****************************************************************************/
/* The DEMO9S12NE64 has 512Kb of FLASH beginning at address 0x0800:0000 and
* 64Kb of SRAM beginning at address 0x2000:0000. When booting from FLASH,
* FLASH memory is aliased to address 0x0000:0000 where the code expects to
* begin execution by jumping to the entry point in the 0x0800:0000 address
* range.
/* The DEMO9S12NE64 has 64Kb of FLASH and 8Kb of SRAM that are assumed to be
* positioned as below:
*/
MEMORY
{
flash (rx) : ORIGIN = 0x08000000, LENGTH = 512K
sram (rwx) : ORIGIN = 0x20000000, LENGTH = 64K
flash (rx) : ORIGIN = 0x0800, LENGTH = 64K
sram (rwx) : ORIGIN = 0x3800, LENGTH = 8K
}
OUTPUT_ARCH(m68hc12)