/* * FreeRTOS Kernel * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * SPDX-License-Identifier: MIT * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of * the Software, and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * https://www.FreeRTOS.org * https://github.com/FreeRTOS * */ /* FreeRTOS includes. */ #include "FreeRTOSConfig.h" /* Xilinx library includes. */ #include "microblaze_exceptions_g.h" #include "xparameters.h" #include "microblaze_instructions.h" /* The context is oversized to allow functions called from the ISR to write back into the caller stack. */ #if defined (__arch64__) #if( XPAR_MICROBLAZE_USE_FPU != 0 ) #define portCONTEXT_SIZE 272 #define portMINUS_CONTEXT_SIZE -272 #else #define portCONTEXT_SIZE 264 #define portMINUS_CONTEXT_SIZE -264 #endif #else #if( XPAR_MICROBLAZE_USE_FPU != 0 ) #define portCONTEXT_SIZE 136 #define portMINUS_CONTEXT_SIZE -136 #else #define portCONTEXT_SIZE 132 #define portMINUS_CONTEXT_SIZE -132 #endif #endif /* Offsets from the stack pointer at which saved registers are placed. */ #if defined (__arch64__) #define portR31_OFFSET 8 #define portR30_OFFSET 16 #define portR29_OFFSET 24 #define portR28_OFFSET 32 #define portR27_OFFSET 40 #define portR26_OFFSET 48 #define portR25_OFFSET 56 #define portR24_OFFSET 64 #define portR23_OFFSET 72 #define portR22_OFFSET 80 #define portR21_OFFSET 88 #define portR20_OFFSET 96 #define portR19_OFFSET 104 #define portR18_OFFSET 112 #define portR17_OFFSET 120 #define portR16_OFFSET 128 #define portR15_OFFSET 136 #define portR14_OFFSET 144 #define portR13_OFFSET 152 #define portR12_OFFSET 160 #define portR11_OFFSET 168 #define portR10_OFFSET 176 #define portR9_OFFSET 184 #define portR8_OFFSET 192 #define portR7_OFFSET 200 #define portR6_OFFSET 208 #define portR5_OFFSET 216 #define portR4_OFFSET 224 #define portR3_OFFSET 232 #define portR2_OFFSET 240 #define portCRITICAL_NESTING_OFFSET 248 #define portMSR_OFFSET 256 #define portFSR_OFFSET 264 #else #define portR31_OFFSET 4 #define portR30_OFFSET 8 #define portR29_OFFSET 12 #define portR28_OFFSET 16 #define portR27_OFFSET 20 #define portR26_OFFSET 24 #define portR25_OFFSET 28 #define portR24_OFFSET 32 #define portR23_OFFSET 36 #define portR22_OFFSET 40 #define portR21_OFFSET 44 #define portR20_OFFSET 48 #define portR19_OFFSET 52 #define portR18_OFFSET 56 #define portR17_OFFSET 60 #define portR16_OFFSET 64 #define portR15_OFFSET 68 #define portR14_OFFSET 72 #define portR13_OFFSET 76 #define portR12_OFFSET 80 #define portR11_OFFSET 84 #define portR10_OFFSET 88 #define portR9_OFFSET 92 #define portR8_OFFSET 96 #define portR7_OFFSET 100 #define portR6_OFFSET 104 #define portR5_OFFSET 108 #define portR4_OFFSET 112 #define portR3_OFFSET 116 #define portR2_OFFSET 120 #define portCRITICAL_NESTING_OFFSET 124 #define portMSR_OFFSET 128 #define portFSR_OFFSET 132 #endif .extern pxCurrentTCB .extern XIntc_DeviceInterruptHandler .extern vTaskSwitchContext .extern uxCriticalNesting .extern pulISRStack .extern ulTaskSwitchRequested .extern vPortExceptionHandler .extern pulStackPointerOnFunctionEntry .global _interrupt_handler .global VPortYieldASM .global vPortStartFirstTask .global vPortExceptionHandlerEntry .macro portSAVE_CONTEXT /* Make room for the context on the stack. */ ADDLIK r1, r1, portMINUS_CONTEXT_SIZE /* Stack general registers. */ SI r31, r1, portR31_OFFSET SI r30, r1, portR30_OFFSET SI r29, r1, portR29_OFFSET SI r28, r1, portR28_OFFSET SI r27, r1, portR27_OFFSET SI r26, r1, portR26_OFFSET SI r25, r1, portR25_OFFSET SI r24, r1, portR24_OFFSET SI r23, r1, portR23_OFFSET SI r22, r1, portR22_OFFSET SI r21, r1, portR21_OFFSET SI r20, r1, portR20_OFFSET SI r19, r1, portR19_OFFSET SI r18, r1, portR18_OFFSET SI r17, r1, portR17_OFFSET SI r16, r1, portR16_OFFSET SI r15, r1, portR15_OFFSET /* R14 is saved later as it needs adjustment if a yield is performed. */ SI r13, r1, portR13_OFFSET SI r12, r1, portR12_OFFSET SI r11, r1, portR11_OFFSET SI r10, r1, portR10_OFFSET SI r9, r1, portR9_OFFSET SI r8, r1, portR8_OFFSET SI r7, r1, portR7_OFFSET SI r6, r1, portR6_OFFSET SI r5, r1, portR5_OFFSET SI r4, r1, portR4_OFFSET SI r3, r1, portR3_OFFSET SI r2, r1, portR2_OFFSET /* Stack the critical section nesting value. */ LI r18, r0, uxCriticalNesting SI r18, r1, portCRITICAL_NESTING_OFFSET /* Stack MSR. */ mfs r18, rmsr SI r18, r1, portMSR_OFFSET #if( XPAR_MICROBLAZE_USE_FPU != 0 ) /* Stack FSR. */ mfs r18, rfsr SI r18, r1, portFSR_OFFSET #endif #if( XPAR_MICROBLAZE_USE_STACK_PROTECTION ) /* Save the stack limits */ mfs r18, rslr swi r18, r1, portSLR_OFFSET mfs r18, rshr swi r18, r1, portSHR_OFFSET #endif /* Save the top of stack value to the TCB. */ LI r3, r0, pxCurrentTCB STORE r1, r0, r3 .endm .macro portRESTORE_CONTEXT /* Load the top of stack value from the TCB. */ LI r18, r0, pxCurrentTCB LOAD r1, r0, r18 #if( XPAR_MICROBLAZE_USE_STACK_PROTECTION ) /* Restore the stack limits -- must not load from r1 (Stack Pointer) because if the address of load or store instruction is out of range, it will trigger Stack Protection Violation exception. */ or r18, r0, r1 lwi r12, r18, portSLR_OFFSET mts rslr, r12 lwi r12, r18, portSHR_OFFSET mts rshr, r12 #endif /* Restore the general registers. */ LI r31, r1, portR31_OFFSET LI r30, r1, portR30_OFFSET LI r29, r1, portR29_OFFSET LI r28, r1, portR28_OFFSET LI r27, r1, portR27_OFFSET LI r26, r1, portR26_OFFSET LI r25, r1, portR25_OFFSET LI r24, r1, portR24_OFFSET LI r23, r1, portR23_OFFSET LI r22, r1, portR22_OFFSET LI r21, r1, portR21_OFFSET LI r20, r1, portR20_OFFSET LI r19, r1, portR19_OFFSET LI r17, r1, portR17_OFFSET LI r16, r1, portR16_OFFSET LI r15, r1, portR15_OFFSET LI r14, r1, portR14_OFFSET LI r13, r1, portR13_OFFSET LI r12, r1, portR12_OFFSET LI r11, r1, portR11_OFFSET LI r10, r1, portR10_OFFSET LI r9, r1, portR9_OFFSET LI r8, r1, portR8_OFFSET LI r7, r1, portR7_OFFSET LI r6, r1, portR6_OFFSET LI r5, r1, portR5_OFFSET LI r4, r1, portR4_OFFSET LI r3, r1, portR3_OFFSET LI r2, r1, portR2_OFFSET /* Reload the rmsr from the stack. */ LI r18, r1, portMSR_OFFSET mts rmsr, r18 #if( XPAR_MICROBLAZE_USE_FPU != 0 ) /* Reload the FSR from the stack. */ LI r18, r1, portFSR_OFFSET mts rfsr, r18 #endif /* Load the critical nesting value. */ LI r18, r1, portCRITICAL_NESTING_OFFSET SI r18, r0, uxCriticalNesting /* Test the critical nesting value. If it is non zero then the task last exited the running state using a yield. If it is zero, then the task last exited the running state through an interrupt. */ XORI r18, r18, 0 BNEI r18, exit_from_yield /* r18 was being used as a temporary. Now restore its true value from the stack. */ LI r18, r1, portR18_OFFSET /* Remove the stack frame. */ ADDLIK r1, r1, portCONTEXT_SIZE /* Return using rtid so interrupts are re-enabled as this function is exited. */ rtid r14, 0 OR r0, r0, r0 .endm /* This function is used to exit portRESTORE_CONTEXT() if the task being returned to last left the Running state by calling taskYIELD() (rather than being preempted by an interrupt). */ .text #ifdef __arch64__ .align 8 #else .align 4 #endif exit_from_yield: /* r18 was being used as a temporary. Now restore its true value from the stack. */ LI r18, r1, portR18_OFFSET /* Remove the stack frame. */ ADDLIK r1, r1, portCONTEXT_SIZE /* Return to the task. */ rtsd r14, 0 OR r0, r0, r0 .text #ifdef __arch64__ .align 8 #else .align 4 #endif _interrupt_handler: portSAVE_CONTEXT /* Stack the return address. */ SI r14, r1, portR14_OFFSET /* Switch to the ISR stack. */ LI r1, r0, pulISRStack #if( XPAR_MICROBLAZE_USE_STACK_PROTECTION ) ori r18, r0, _stack_end mts rslr, r18 ori r18, r0, _stack mts rshr, r18 #endif /* The parameter to the interrupt handler. */ ORI r5, r0, configINTERRUPT_CONTROLLER_TO_USE /* Execute any pending interrupts. */ BRALID r15, XIntc_DeviceInterruptHandler OR r0, r0, r0 /* See if a new task should be selected to execute. */ LI r18, r0, ulTaskSwitchRequested OR r18, r18, r0 /* If ulTaskSwitchRequested is already zero, then jump straight to restoring the task that is already in the Running state. */ BEQI r18, task_switch_not_requested /* Set ulTaskSwitchRequested back to zero as a task switch is about to be performed. */ SI r0, r0, ulTaskSwitchRequested /* ulTaskSwitchRequested was not 0 when tested. Select the next task to execute. */ BRALID r15, vTaskSwitchContext OR r0, r0, r0 task_switch_not_requested: /* Restore the context of the next task scheduled to execute. */ portRESTORE_CONTEXT .text #ifdef __arch64__ .align 8 #else .align 4 #endif VPortYieldASM: portSAVE_CONTEXT /* Modify the return address so a return is done to the instruction after the call to VPortYieldASM. */ ADDI r14, r14, 8 SI r14, r1, portR14_OFFSET /* Switch to use the ISR stack. */ LI r1, r0, pulISRStack #if( XPAR_MICROBLAZE_USE_STACK_PROTECTION ) ori r18, r0, _stack_end mts rslr, r18 ori r18, r0, _stack mts rshr, r18 #endif /* Select the next task to execute. */ BRALID r15, vTaskSwitchContext OR r0, r0, r0 /* Restore the context of the next task scheduled to execute. */ portRESTORE_CONTEXT .text #ifdef __arch64__ .align 8 #else .align 4 #endif vPortStartFirstTask: portRESTORE_CONTEXT #if ( MICROBLAZE_EXCEPTIONS_ENABLED == 1 ) && ( configINSTALL_EXCEPTION_HANDLERS == 1 ) .text #ifdef __arch64__ .align 8 #else .align 4 #endif vPortExceptionHandlerEntry: /* Take a copy of the stack pointer before vPortExecptionHandler is called, storing its value prior to the function stack frame being created. */ SI r1, r0, pulStackPointerOnFunctionEntry BRALID r15, vPortExceptionHandler OR r0, r0, r0 #endif /* ( MICROBLAZE_EXCEPTIONS_ENABLED == 1 ) && ( configINSTALL_EXCEPTION_HANDLERS == 1 ) */