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2009-08-11 Josh Switnicki <josh.switnicki@utoronto.ca>

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* cpu.c, cpu_asm.S, rtems/score/cpu.h: Fix bug in
	_CPU_Context_Initialize.
This commit is contained in:
Joel Sherrill
2009-08-11 17:03:01 +00:00
parent 79d490aa58
commit cdfe85a7f3
4 changed files with 111 additions and 115 deletions
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5
cpukit/score/cpu/avr/ChangeLog
View File

@@ -1,3 +1,8 @@
2009-08-11 Josh Switnicki <josh.switnicki@utoronto.ca>
* cpu.c, cpu_asm.S, rtems/score/cpu.h: Fix bug in
_CPU_Context_Initialize.
2009-08-05 Josh Switnicki <josh.switnicki@utoronto.ca>
* Makefile.am: added AVR specific Header files to score/cpu/avr/avr.

80
cpukit/score/cpu/avr/cpu.c
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@@ -30,7 +30,6 @@
*/
void _CPU_Initialize(void)
{
printk( "AVR CPU Initialize\n" );
/*
* If there is not an easy way to initialize the FP context
@@ -42,82 +41,6 @@ void _CPU_Initialize(void)
/* FP context initialization support goes here */
}
/*PAGE
*
* _CPU_Context_Initialize
*
* This kernel routine initializes the basic non-FP context area associated
* with each thread.
*
* Input parameters:
* the_context - pointer to the context area
* stack_base - address of memory for the SPARC
* size - size in bytes of the stack area
* new_level - interrupt level for this context area
* entry_point - the starting execution point for this this context
* is_fp - TRUE if this context is associated with an FP thread
*
* Output parameters: NONE
*/
void _CPU_Context_Initialize(
Context_Control *the_context,
uint32_t *stack_base,
uint32_t size,
uint32_t new_level,
void *entry_point,
bool is_fp
)
{
uint16_t stack;
uint16_t start;
uint8_t *tmp_sp;
uint8_t start_low;
uint8_t start_high;
/* calc stack high end */
stack = (uint16_t) (stack_base) + (uint16_t) (size);
/* calc stack pointer initial value */
the_context->stack_pointer = (stack - 18);
/* put the entry point on the stack */
start = (uint16_t) entry_point;
start_low = start & 0xff;
start_high = start >> 8;
tmp_sp = (uint8_t *) (stack+1);
tmp_sp[0] = start_high;
tmp_sp[1] = start_low;
if (new_level) the_context->status = 0x00; //interrupts are enabled
else the_context->status = 0x80; //interrupts are disabled
/*
* JOEL: Why if I comment out these three lines does ticker not run?
*/
#if 1
printk( "tmp_sp=0x%04x ", ((uint16_t)tmp_sp) );
printk("the_context = 0x%x\n", the_context);
printk("entry = 0x%x\n", entry_point);
#endif
#if 0
printk("sp = 0x%x\n\n",stack);
{ int i; uint8_t *p;
p = (uint8_t *)(stack - 18);
for( i=0 ; i<=20 ; i+=8 ) {
printk( "0x%04x ", ((uint16_t)&p[i]) );
printk(
"0x%02x 0x%02x 0x%02x 0x%02x ",
p[i + 0], p[i + 1], p[i + 2], p[i + 3]
);
printk(
"0x%02x 0x%02x 0x%02x 0x%02x\n",
p[i + 4], p[i + 5], p[i + 6], p[i + 7]
);
}
}
#endif
}
/*PAGE
*
* _CPU_ISR_Get_level
@@ -132,8 +55,9 @@ uint32_t _CPU_ISR_Get_level( void )
/*
* This routine returns the current interrupt level.
*/
if((SREG & 0x80))return 1;
else return 0;
return 0;
}
/*PAGE

137
cpukit/score/cpu/avr/cpu_asm.S
View File

@@ -208,11 +208,21 @@ SYM(_CPU_Context_restore_fp):
PUBLIC(_CPU_Context_switch)
SYM(_CPU_Context_switch):
mov r26, r24 /* r26,r27 is X or current context */
mov r26, r24 /*r26,r27 is X*/
mov r27, r25
mov r24, r22 /* r24,r25 is heir context */
mov r24, r22
mov r25, r23
/*save registers*/
#if 1
/*if this section is removed there is a problem.*/
/*debug section start*/
pop r22
pop r23
push r22
push r23
/*debug section end*/
#endif
push r2
push r3
push r4
@@ -229,36 +239,42 @@ SYM(_CPU_Context_switch):
push r15
push r16
push r17
push r28
push r29
/*load sreg*/
lds r23,0x5F /*load sreg*/
lds r23,0x5f /*load sreg*/
/*disable interrupts*/
cli
/*load stack pointer*/
lds r22,0x5D /*spl*/
lds r21,0x5E /*sph*/
/*save sp to context struct*/
lds r22,0x5d /*spl*/
lds r21,0x5e /*sph*/
/*save sreg and sp to context struct*/
/*save low then high byte --- verify this delete when verified*/
st X+, r22
st X+, r21
/*save sreg and sp to context struct*/
st X, r23
PUBLIC(_CPU_Context_restore)
SYM(_CPU_Context_restore):
mov r26,r24 /* R26/27 are X */
mov r27,r25
/*restore stack pointer*/
ld r25, X+
ld r24, X+
sts 0x5E, r24 /*sph*/
sts 0x5D, r25 /*spl*/
sts 0x5E,r24 /*sph*/
sts 0x5D ,r25 /*spl*/
/*restore registers from stack*/
pop r29
pop r28
pop r17
pop r16
pop r15
@@ -275,41 +291,92 @@ SYM(_CPU_Context_restore):
pop r4
pop r3
pop r2
/*restore status register*/
ld r23, X
sts 0x5f,r23 /*sreg*/
/*restore sreg*/
ld r25, X
sts 0x5f,r25 /*sreg*/
pop r30
pop r31
IJMP
ret
/*
* _CPU_Context_restore
/*PAGE
*
* This routine is generally used only to restart self in an
* efficient manner. It may simply be a label in _CPU_Context_switch.
* _CPU_Context_Initialize
*
* NOTE: May be unnecessary to reload some registers.
* This kernel routine initializes the basic non-FP context area associated
* with each thread.
*
* NO_CPU Specific Information:
* Input parameters:
* the_context - pointer to the context area
* stack_base - address of memory for the SPARC
* size - size in bytes of the stack area
* new_level - interrupt level for this context area
* entry_point - the starting execution point for this this context
* is_fp - TRUE if this context is associated with an FP thread
*
* XXX document implementation including references if appropriate
* the_context is in r25,r24
* entry point is in r13,r12
* stack base is in r23, r22
* size is in r21, r20, r19,r18
* newleve is in r14,r15, r16, 17
*
*
* Output parameters: NONE
*/
PUBLIC(_CPU_Context_Initialize)
SYM(_CPU_Context_Initialize):
//save caller saved regs
PUSH R10
PUSH R11
PUSH R12
PUSH R13
PUSH R14
PUSH R15
PUSH R16
PUSH R17
PUSH R28
PUSH R29
//calculate new stack pointer
ADD R22, R18
ADC R23, R19
MOV R26, R22
MOV R27, R23
//Initialize stack with entry point
ST -X, R13
ST -X, R12
//store new stack pointer in context control
SBIW R26, 0X13 /*subtract 33 to account for registers*/
MOV R28, R24
MOV R29, R25
STD Y+1, R27 //save stack pointer high to context control
ST Y, R26 //save stack pointer low to context control
//set interrupt level in new context
LDI R18, 0 //set sreg in new context to zero
STD Y+2, R18 //interrupts not enabled
MOV R18, R14
CPI R18, 0
BRNE NEW_LEVEL_ZERO
LDI R18, 0X80 //set sreg in new context to 0x80
STD Y+2, R18 //interupts enabled
NEW_LEVEL_ZERO:
//restore caller saved regs
POP R29
POP R28
POP R17
POP R16
POP R15
POP R14
POP R13
POP R12
POP R11
POP R10
RET
void _CPU_Context_restore(
Context_Control *new_context
)
{
printk( "AVR _CPU_Context_restore\n" );
}
*/
/*
PUBLIC(_CPU_Context_restore)
SYM(_CPU_Context_restore):
//call printk("AVR _CPU_Context_restore\n")
ret
*/
/* void __ISR_Handler()
*

2
cpukit/score/cpu/avr/rtems/score/cpu.h
View File

@@ -762,7 +762,7 @@ uint32_t _CPU_ISR_Get_level( void );
*/
#define _CPU_Context_Restart_self( _the_context ) \
_CPU_Context_restore( (_the_context) );
_CPU_Context_restore( _the_context );
/*
* The purpose of this macro is to allow the initial pointer into