armv8-m: Remove redundant constant pools (#1035)

Currently in Armv8-M GCC/ArmClang ports, constant pool is used to
define literals needed for `ldr` instructions. However, those
constant pools are defined with `.align 4` which increases code size.
Instead of defining the constant pool with `.align 4`, let the
compiler hanlde the constant pool and the required alignment.

Signed-off-by: Devaraj Ranganna <devaraj.ranganna@arm.com>
Co-authored-by: chinglee-iot <61685396+chinglee-iot@users.noreply.github.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
This commit is contained in:
Devaraj Ranganna 2024-04-18 19:45:04 +01:00 committed by GitHub
parent bbc058967b
commit 8d280217cd
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GPG key ID: B5690EEEBB952194
15 changed files with 372 additions and 786 deletions

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@ -52,23 +52,23 @@
" .syntax unified \n"
" \n"
" program_mpu_first_task: \n"
" ldr r2, pxCurrentTCBConst2 \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r2, =pxCurrentTCB \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r0, [r2] \n" /* r0 = pxCurrentTCB. */
" \n"
" dmb \n" /* Complete outstanding transfers before disabling MPU. */
" ldr r1, xMPUCTRLConst2 \n" /* r1 = 0xe000ed94 [Location of MPU_CTRL]. */
" ldr r1, =0xe000ed94 \n" /* r1 = 0xe000ed94 [Location of MPU_CTRL]. */
" ldr r2, [r1] \n" /* Read the value of MPU_CTRL. */
" bic r2, #1 \n" /* r2 = r2 & ~1 i.e. Clear the bit 0 in r2. */
" str r2, [r1] \n" /* Disable MPU. */
" \n"
" adds r0, #4 \n" /* r0 = r0 + 4. r0 now points to MAIR0 in TCB. */
" ldr r1, [r0] \n" /* r1 = *r0 i.e. r1 = MAIR0. */
" ldr r2, xMAIR0Const2 \n" /* r2 = 0xe000edc0 [Location of MAIR0]. */
" ldr r2, =0xe000edc0 \n" /* r2 = 0xe000edc0 [Location of MAIR0]. */
" str r1, [r2] \n" /* Program MAIR0. */
" \n"
" adds r0, #4 \n" /* r0 = r0 + 4. r0 now points to first RBAR in TCB. */
" ldr r1, xRNRConst2 \n" /* r1 = 0xe000ed98 [Location of RNR]. */
" ldr r2, xRBARConst2 \n" /* r2 = 0xe000ed9c [Location of RBAR]. */
" ldr r1, =0xe000ed98 \n" /* r1 = 0xe000ed98 [Location of RNR]. */
" ldr r2, =0xe000ed9c \n" /* r2 = 0xe000ed9c [Location of RBAR]. */
" \n"
" movs r3, #4 \n" /* r3 = 4. */
" str r3, [r1] \n" /* Program RNR = 4. */
@ -86,14 +86,14 @@
" stmia r2, {r4-r11} \n" /* Write 4 set of RBAR/RLAR registers using alias registers. */
#endif /* configTOTAL_MPU_REGIONS == 16 */
" \n"
" ldr r1, xMPUCTRLConst2 \n" /* r1 = 0xe000ed94 [Location of MPU_CTRL]. */
" ldr r1, =0xe000ed94 \n" /* r1 = 0xe000ed94 [Location of MPU_CTRL]. */
" ldr r2, [r1] \n" /* Read the value of MPU_CTRL. */
" orr r2, #1 \n" /* r2 = r2 | 1 i.e. Set the bit 0 in r2. */
" str r2, [r1] \n" /* Enable MPU. */
" dsb \n" /* Force memory writes before continuing. */
" \n"
" restore_context_first_task: \n"
" ldr r2, pxCurrentTCBConst2 \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r2, =pxCurrentTCB \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r0, [r2] \n" /* r0 = pxCurrentTCB.*/
" ldr r1, [r0] \n" /* r1 = Location of saved context in TCB. */
" \n"
@ -113,13 +113,6 @@
" mov r0, #0 \n"
" msr basepri, r0 \n" /* Ensure that interrupts are enabled when the first task starts. */
" bx lr \n"
" \n"
" .align 4 \n"
" pxCurrentTCBConst2: .word pxCurrentTCB \n"
" xMPUCTRLConst2: .word 0xe000ed94 \n"
" xMAIR0Const2: .word 0xe000edc0 \n"
" xRNRConst2: .word 0xe000ed98 \n"
" xRBARConst2: .word 0xe000ed9c \n"
);
}
@ -131,7 +124,7 @@
(
" .syntax unified \n"
" \n"
" ldr r2, pxCurrentTCBConst2 \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r2, =pxCurrentTCB \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r1, [r2] \n" /* Read pxCurrentTCB. */
" ldr r0, [r1] \n" /* Read top of stack from TCB - The first item in pxCurrentTCB is the task top of stack. */
" \n"
@ -145,9 +138,6 @@
" mov r0, #0 \n"
" msr basepri, r0 \n" /* Ensure that interrupts are enabled when the first task starts. */
" bx r2 \n" /* Finally, branch to EXC_RETURN. */
" \n"
" .align 4 \n"
"pxCurrentTCBConst2: .word pxCurrentTCB \n"
);
}
@ -166,8 +156,6 @@ BaseType_t xIsPrivileged( void ) /* __attribute__ (( naked )) */
" movne r0, #0 \n" /* CONTROL[0]!=0. Return false to indicate that the processor is not privileged. */
" moveq r0, #1 \n" /* CONTROL[0]==0. Return true to indicate that the processor is privileged. */
" bx lr \n" /* Return. */
" \n"
" .align 4 \n"
::: "r0", "memory"
);
}
@ -209,7 +197,7 @@ void vStartFirstTask( void ) /* __attribute__ (( naked )) PRIVILEGED_FUNCTION */
(
" .syntax unified \n"
" \n"
" ldr r0, xVTORConst \n" /* Use the NVIC offset register to locate the stack. */
" ldr r0, =0xe000ed08 \n" /* Use the NVIC offset register to locate the stack. */
" ldr r0, [r0] \n" /* Read the VTOR register which gives the address of vector table. */
" ldr r0, [r0] \n" /* The first entry in vector table is stack pointer. */
" msr msp, r0 \n" /* Set the MSP back to the start of the stack. */
@ -219,9 +207,6 @@ void vStartFirstTask( void ) /* __attribute__ (( naked )) PRIVILEGED_FUNCTION */
" isb \n"
" svc %0 \n" /* System call to start the first task. */
" nop \n"
" \n"
" .align 4 \n"
"xVTORConst: .word 0xe000ed08 \n"
::"i" ( portSVC_START_SCHEDULER ) : "memory"
);
}
@ -267,7 +252,7 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
(
" .syntax unified \n"
" \n"
" ldr r2, pxCurrentTCBConst \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r2, =pxCurrentTCB \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r0, [r2] \n" /* r0 = pxCurrentTCB. */
" ldr r1, [r0] \n" /* r1 = Location in TCB where the context should be saved. */
" mrs r2, psp \n" /* r2 = PSP. */
@ -303,23 +288,23 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
" msr basepri, r0 \n" /* Enable interrupts. */
" \n"
" program_mpu: \n"
" ldr r2, pxCurrentTCBConst \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r2, =pxCurrentTCB \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r0, [r2] \n" /* r0 = pxCurrentTCB. */
" \n"
" dmb \n" /* Complete outstanding transfers before disabling MPU. */
" ldr r1, xMPUCTRLConst \n" /* r1 = 0xe000ed94 [Location of MPU_CTRL]. */
" ldr r1, =0xe000ed94 \n" /* r1 = 0xe000ed94 [Location of MPU_CTRL]. */
" ldr r2, [r1] \n" /* Read the value of MPU_CTRL. */
" bic r2, #1 \n" /* r2 = r2 & ~1 i.e. Clear the bit 0 in r2. */
" str r2, [r1] \n" /* Disable MPU. */
" \n"
" adds r0, #4 \n" /* r0 = r0 + 4. r0 now points to MAIR0 in TCB. */
" ldr r1, [r0] \n" /* r1 = *r0 i.e. r1 = MAIR0. */
" ldr r2, xMAIR0Const \n" /* r2 = 0xe000edc0 [Location of MAIR0]. */
" ldr r2, =0xe000edc0 \n" /* r2 = 0xe000edc0 [Location of MAIR0]. */
" str r1, [r2] \n" /* Program MAIR0. */
" \n"
" adds r0, #4 \n" /* r0 = r0 + 4. r0 now points to first RBAR in TCB. */
" ldr r1, xRNRConst \n" /* r1 = 0xe000ed98 [Location of RNR]. */
" ldr r2, xRBARConst \n" /* r2 = 0xe000ed9c [Location of RBAR]. */
" ldr r1, =0xe000ed98 \n" /* r1 = 0xe000ed98 [Location of RNR]. */
" ldr r2, =0xe000ed9c \n" /* r2 = 0xe000ed9c [Location of RBAR]. */
" \n"
" movs r3, #4 \n" /* r3 = 4. */
" str r3, [r1] \n" /* Program RNR = 4. */
@ -337,14 +322,14 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
" stmia r2, {r4-r11} \n" /* Write 4 set of RBAR/RLAR registers using alias registers. */
#endif /* configTOTAL_MPU_REGIONS == 16 */
" \n"
" ldr r1, xMPUCTRLConst \n" /* r1 = 0xe000ed94 [Location of MPU_CTRL]. */
" ldr r1, =0xe000ed94 \n" /* r1 = 0xe000ed94 [Location of MPU_CTRL]. */
" ldr r2, [r1] \n" /* Read the value of MPU_CTRL. */
" orr r2, #1 \n" /* r2 = r2 | 1 i.e. Set the bit 0 in r2. */
" str r2, [r1] \n" /* Enable MPU. */
" dsb \n" /* Force memory writes before continuing. */
" \n"
" restore_context: \n"
" ldr r2, pxCurrentTCBConst \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r2, =pxCurrentTCB \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r0, [r2] \n" /* r0 = pxCurrentTCB.*/
" ldr r1, [r0] \n" /* r1 = Location of saved context in TCB. */
" \n"
@ -369,13 +354,6 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
" restore_context_done: \n"
" str r1, [r0] \n" /* Save the location where the context should be saved next as the first member of TCB. */
" bx lr \n"
" \n"
" .align 4 \n"
" pxCurrentTCBConst: .word pxCurrentTCB \n"
" xMPUCTRLConst: .word 0xe000ed94 \n"
" xMAIR0Const: .word 0xe000edc0 \n"
" xRNRConst: .word 0xe000ed98 \n"
" xRBARConst: .word 0xe000ed9c \n"
::"i" ( configMAX_SYSCALL_INTERRUPT_PRIORITY )
);
}
@ -400,7 +378,7 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
" mov r3, lr \n" /* r3 = LR/EXC_RETURN. */
" stmdb r0!, {r2-r11} \n" /* Store on the stack - PSPLIM, LR and registers that are not automatically saved. */
" \n"
" ldr r2, pxCurrentTCBConst \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r2, =pxCurrentTCB \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r1, [r2] \n" /* Read pxCurrentTCB. */
" str r0, [r1] \n" /* Save the new top of stack in TCB. */
" \n"
@ -412,7 +390,7 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
" mov r0, #0 \n" /* r0 = 0. */
" msr basepri, r0 \n" /* Enable interrupts. */
" \n"
" ldr r2, pxCurrentTCBConst \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r2, =pxCurrentTCB \n" /* Read the location of pxCurrentTCB i.e. &( pxCurrentTCB ). */
" ldr r1, [r2] \n" /* Read pxCurrentTCB. */
" ldr r0, [r1] \n" /* The first item in pxCurrentTCB is the task top of stack. r0 now points to the top of stack. */
" \n"
@ -427,9 +405,6 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
" msr psplim, r2 \n" /* Restore the PSPLIM register value for the task. */
" msr psp, r0 \n" /* Remember the new top of stack for the task. */
" bx r3 \n"
" \n"
" .align 4 \n"
"pxCurrentTCBConst: .word pxCurrentTCB \n"
::"i" ( configMAX_SYSCALL_INTERRUPT_PRIORITY )
);
}
@ -487,11 +462,8 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
" ite eq \n"
" mrseq r0, msp \n"
" mrsne r0, psp \n"
" ldr r1, svchandler_address_const \n"
" ldr r1, =vPortSVCHandler_C \n"
" bx r1 \n"
" \n"
" .align 4 \n"
"svchandler_address_const: .word vPortSVCHandler_C \n"
);
}