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Fix syscall parameter passing for the case where the number of parameters is >4

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5767 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2013-03-21 00:25:17 +00:00
parent c86f502f2e
commit 87bb6ceb5b
4 changed files with 88 additions and 35 deletions
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15
arch/arm/include/armv6-m/syscall.h
View File

@ -156,7 +156,10 @@ static inline uintptr_t sys_call3(unsigned int nbr, uintptr_t parm1,
return reg0;
}
/* SVC call with SYS_ call number and four parameters */
/* SVC call with SYS_ call number and four parameters.
*
* NOTE the nonstandard parameter passing: parm4 is in R4
*/
static inline uintptr_t sys_call4(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2, uintptr_t parm3,
@ -180,7 +183,10 @@ static inline uintptr_t sys_call4(unsigned int nbr, uintptr_t parm1,
return reg0;
}
/* SVC call with SYS_ call number and five parameters */
/* SVC call with SYS_ call number and five parameters.
*
* NOTE the nonstandard parameter passing: parm4 and parm5 are in R4 and R5
*/
static inline uintptr_t sys_call5(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2, uintptr_t parm3,
@ -205,7 +211,10 @@ static inline uintptr_t sys_call5(unsigned int nbr, uintptr_t parm1,
return reg0;
}
/* SVC call with SYS_ call number and six parameters */
/* SVC call with SYS_ call number and six parameters.
*
* NOTE the nonstandard parameter passing: parm4-parm6 are in R4-R6
*/
static inline uintptr_t sys_call6(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2, uintptr_t parm3,

15
arch/arm/include/armv7-m/syscall.h
View File

@ -156,7 +156,10 @@ static inline uintptr_t sys_call3(unsigned int nbr, uintptr_t parm1,
return reg0;
}
/* SVC call with SYS_ call number and four parameters */
/* SVC call with SYS_ call number and four parameters.
*
* NOTE the nonstandard parameter passing: parm4 is in R4
*/
static inline uintptr_t sys_call4(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2, uintptr_t parm3,
@ -180,7 +183,10 @@ static inline uintptr_t sys_call4(unsigned int nbr, uintptr_t parm1,
return reg0;
}
/* SVC call with SYS_ call number and five parameters */
/* SVC call with SYS_ call number and five parameters.
*
* NOTE the nonstandard parameter passing: parm4 and parm5 are in R4 and R5
*/
static inline uintptr_t sys_call5(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2, uintptr_t parm3,
@ -205,7 +211,10 @@ static inline uintptr_t sys_call5(unsigned int nbr, uintptr_t parm1,
return reg0;
}
/* SVC call with SYS_ call number and six parameters */
/* SVC call with SYS_ call number and six parameters.
*
* NOTE the nonstandard parameter passing: parm4-parm6 are in R4-R6
*/
static inline uintptr_t sys_call6(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2, uintptr_t parm3,

44
arch/arm/src/armv6-m/up_svcall.c
View File

@ -91,17 +91,32 @@
* Name: dispatch_syscall
*
* Description:
* Call the stub function corresponding to the system call.
* Call the stub function corresponding to the system call. NOTE the non-
* standard parameter passing:
*
* R0 - Need not be preserved until after the stub is called.
* R1-R3 - Need to be preserved until the stub is called. The values of
* R0 and R1 returned by the stub must be preserved.
* R4-R11 must be preserved to support the expectations of the user-space
* callee
* R12 - Need not be preserved
* R13 - (stack pointer)
* R14 - Need not be preserved
* R15 - (PC)
* R0 = SYS_ call number
* R1 = parm0
* R2 = parm1
* R3 = parm2
* R4 = parm3
* R5 = parm4
* R6 = parm5
*
* The values of R4-R5 may be preserved in the proxy called by the user
* code if they are used (but otherwise will not be).
*
* Register usage:
*
* R0 - Need not be preserved.
* R1-R3 - Need to be preserved until the stub is called. The values of
* R0 and R1 returned by the stub must be preserved.
* R4-R11 must be preserved to support the expectations of the user-space
* callee. R4-R6 may have been preserved by the proxy, but don't know
* for sure.
* R12 - Need not be preserved
* R13 - (stack pointer)
* R14 - Need not be preserved
* R15 - (PC)
*
****************************************************************************/
@ -112,14 +127,19 @@ static void dispatch_syscall(void)
__asm__ __volatile__
(
" push {r4, r5}\n" /* Save R4 and R5 */
" sub sp, sp, #12\n" /* Create a stack frame to hold 3 parms */
" str r4, [sp, #0]\n" /* Move parameter 4 (if any) into position */
" str r5, [sp, #4]\n" /* Move parameter 5 (if any) into position */
" str r6, [sp, #8]\n" /* Move parameter 6 (if any) into position */
" mov r5, lr\n" /* Save lr in R5 */
" ldr r4, =g_stublookup\n" /* R4=The base of the stub lookup table */
" lsl r0, r0, #2\n" /* R0=Offset of the stub for this syscall */
" ldr r4, [r4, r0]\n" /* R4=Address of the stub for this syscall */
" blx r5\n" /* Call the stub (modifies lr) */
" mov lr, r5\n" /* Restore lr */
" pop {r4, r5}\n" /* Restore R4 and R5*/
" mov r2, r0\n" /* R2=Saves return value in R0 */
" add sp, sp, #12\n" /* Destroy the stack frame */
" pop {r4, r5}\n" /* Recover R4 and R5 */
" mov r2, r0\n" /* R2=Save return value in R2 */
" mov r0, #3\n" /* R0=SYS_syscall_return */
" svc 0" /* Return from the syscall */
);

49
arch/arm/src/armv7-m/up_svcall.c
View File

@ -88,20 +88,32 @@
****************************************************************************/
/****************************************************************************
* Name: dispatch_syscall
* Call the stub function corresponding to the system call. NOTE the non-
* standard parameter passing:
*
* Description:
* Call the stub function corresponding to the system call.
* R0 = SYS_ call number
* R1 = parm0
* R2 = parm1
* R3 = parm2
* R4 = parm3
* R5 = parm4
* R6 = parm5
*
* R0 - Need not be preserved until after the stub is called.
* R1-R3 - Need to be preserved until the stub is called. The values of
* R0 and R1 returned by the stub must be preserved.
* R4-R11 must be preserved to support the expectations of the user-space
* callee
* R12 - Need not be preserved
* R13 - (stack pointer)
* R14 - Need not be preserved
* R15 - (PC)
* The values of R4-R5 may be preserved in the proxy called by the user
* code if they are used (but otherwise will not be).
*
* Register usage:
*
* R0 - Need not be preserved.
* R1-R3 - Need to be preserved until the stub is called. The values of
* R0 and R1 returned by the stub must be preserved.
* R4-R11 must be preserved to support the expectations of the user-space
* callee. R4-R6 may have been preserved by the proxy, but don't know
* for sure.
* R12 - Need not be preserved
* R13 - (stack pointer)
* R14 - Need not be preserved
* R15 - (PC)
*
****************************************************************************/
@ -111,14 +123,17 @@ static void dispatch_syscall(void)
{
__asm__ __volatile__
(
" push {r4}\n" /* Save R4 */
" mov r4, lr\n" /* Save lr in R4 */
" sub sp, sp, #16\n" /* Create a stack frame to hold 3 parms + lr */
" str r4, [sp, #0]\n" /* Move parameter 4 (if any) into position */
" str r5, [sp, #4]\n" /* Move parameter 5 (if any) into position */
" str r6, [sp, #8]\n" /* Move parameter 6 (if any) into position */
" str lr, [sp, #12]\n" /* Save lr in the stack frame */
" ldr ip, =g_stublookup\n" /* R12=The base of the stub lookup table */
" ldr ip, [ip, r0, lsl #2]\n" /* R12=The address of the stub for this syscall */
" blx ip\n" /* Call the stub (modifies lr)*/
" mov lr, r4\n" /* Restore lr */
" pop {r4}\n" /* Restore r4 */
" mov r2, r0\n" /* R2=Saved return value in R0 */
" ldr lr, [sp, #12]\n" /* Restore lr */
" add sp, sp, #16\n" /* Destroy the stack frame */
" mov r2, r0\n" /* R2=Save return value in R2 */
" mov r0, #3\n" /* R0=SYS_syscall_return */
" svc 0" /* Return from the syscall */
);