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arm: Fix ARMv7-M exception handler

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Store the stack pointer of the exception context to the exception frame.

Close #3987.
This commit is contained in:
Sebastian Huber
2020-05-27 09:24:54 +02:00
parent 934cbe7d9f
commit bd750c9e6e
1 changed files with 15 additions and 8 deletions
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23
cpukit/score/cpu/arm/armv7m-exception-default.c
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@@ -40,13 +40,20 @@ void __attribute__((naked)) _ARMV7M_Exception_default( void )
"stm sp, {r0-r12}\n"
"tst lr, #4\n" /* Check if bit 2 of LR is zero. If so, PSR.Z = 1 */
"itte eq\n" /* IF bit 2 of LR is zero... (PSR.Z == 1) */
"mrseq r0, msp\n" /* THEN we were using MSP. */
"addeq r0, %[cpufsz]\n" /* THEN, set r0 = old MSP value. */
"mrsne r0, psp\n" /* ELSE it's not zero; we were using PSP. */
"add r2, r0, %[v7mlroff]\n"
"add r1, sp, %[cpulroff]\n"
"ldm r2, {r3-r5}\n" /* Grab LR, PC and PSR from the stack.. */
"stm r1, {r3-r5}\n" /* ..and store them in our CPU_Exception_frame. */
"mrseq r3, msp\n" /* THEN we were using MSP */
"addeq r3, %[cpufsz]\n" /* THEN, set r3 = old MSP value */
"mrsne r3, psp\n" /* ELSE it is not zero; we were using PSP */
"add r2, r3, %[v7mlroff]\n"
"add r1, sp, %[cpuspoff]\n"
"ldm r2, {r4-r6}\n" /* Grab LR, PC and xPSR from the stack */
"tst lr, #16\n" /* Check if we have an FP state on the frame */
"ite eq\n"
"addeq r3, #104\n" /* Back to previous SP with FP state */
"addne r3, #32\n" /* Back to previous SP without FP state */
"tst r6, #512\n" /* Check xPSR if the SP was aligned */
"it ne\n"
"addne r3, #4\n" /* Undo alignment */
"stm r1, {r3-r6}\n" /* Store to CPU_Exception_frame */
"mrs r1, ipsr\n"
"str r1, [sp, %[cpuvecoff]]\n"
@@ -85,7 +92,7 @@ void __attribute__((naked)) _ARMV7M_Exception_default( void )
"b _ARM_Exception_default\n"
:
: [cpufsz] "i" (sizeof(CPU_Exception_frame)),
[cpulroff] "i" (offsetof(CPU_Exception_frame, register_lr)),
[cpuspoff] "i" (offsetof(CPU_Exception_frame, register_sp)),
[v7mlroff] "i" (offsetof(ARMV7M_Exception_frame, register_lr)),
[cpuvecoff] "J" (offsetof(CPU_Exception_frame, vector)),
[cpuvfpoff] "i" (ARM_EXCEPTION_FRAME_VFP_CONTEXT_OFFSET),