Save changes to the RISC-V port layer before making changes necessary to support pulpino too:

+ Switch positions of the asm functions used to start the kernel and handle traps to enable one to reference to the other.
+ Handle external interrupts (working with Renode emulator).
+ The _sp linker variable is now called __freertos_irq_stack_top.
This commit is contained in:
Richard Barry 2018-12-16 20:21:29 +00:00
parent 866635d2ad
commit 7cc42b2ab6
3 changed files with 71 additions and 62 deletions

View file

@ -50,49 +50,7 @@
.extern pullNextTime
.extern ulTimerIncrementsForOneTick
.extern xISRStackTop
/*-----------------------------------------------------------*/
.align 8
xPortStartFirstTask:
la t0, vPortTrapHandler
csrw mtvec, t0
lw sp, pxCurrentTCB /* Load pxCurrentTCB. */
lw sp, 0( sp ) /* Read sp from first TCB member. */
lw x1, 0( sp ) /* Note for starting the scheduler the exception return address is used as the function return address. */
lw x5, 2 * WORD_SIZE( sp ) /* t0 */
lw x6, 3 * WORD_SIZE( sp ) /* t1 */
lw x7, 4 * WORD_SIZE( sp ) /* t2 */
lw x8, 5 * WORD_SIZE( sp ) /* s0/fp */
lw x9, 6 * WORD_SIZE( sp ) /* s1 */
lw x10, 7 * WORD_SIZE( sp ) /* a0 */
lw x11, 8 * WORD_SIZE( sp ) /* a1 */
lw x12, 9 * WORD_SIZE( sp ) /* a2 */
lw x13, 10 * WORD_SIZE( sp ) /* a3 */
lw x14, 11 * WORD_SIZE( sp ) /* a4 */
lw x15, 12 * WORD_SIZE( sp ) /* a5 */
lw x16, 13 * WORD_SIZE( sp ) /* a6 */
lw x17, 14 * WORD_SIZE( sp ) /* a7 */
lw x18, 15 * WORD_SIZE( sp ) /* s2 */
lw x19, 16 * WORD_SIZE( sp ) /* s3 */
lw x20, 17 * WORD_SIZE( sp ) /* s4 */
lw x21, 18 * WORD_SIZE( sp ) /* s5 */
lw x22, 19 * WORD_SIZE( sp ) /* s6 */
lw x23, 20 * WORD_SIZE( sp ) /* s7 */
lw x24, 21 * WORD_SIZE( sp ) /* s8 */
lw x25, 22 * WORD_SIZE( sp ) /* s9 */
lw x26, 23 * WORD_SIZE( sp ) /* s10 */
lw x27, 24 * WORD_SIZE( sp ) /* s11 */
lw x28, 25 * WORD_SIZE( sp ) /* t3 */
lw x29, 26 * WORD_SIZE( sp ) /* t4 */
lw x30, 27 * WORD_SIZE( sp ) /* t5 */
lw x31, 28 * WORD_SIZE( sp ) /* t6 */
addi sp, sp, CONTEXT_SIZE
csrs mstatus, 8 /* Enable machine interrupts. */
ret
.extern vPortHandleInterrupt
/*-----------------------------------------------------------*/
@ -152,7 +110,7 @@ test_if_timer:
lui t0, 0x80000
addi t1,t0, 7 /* 0x80000007 == machine timer interrupt. */
bne a0, t1, as_yet_unhandled
bne a0, t1, test_if_external_interrupt
lw t0, pullMachineTimerCompareRegister /* Load address of compare register into t0. */
lw t1, pullNextTime /* Load the address of ullNextTime into t1. */
@ -172,9 +130,15 @@ test_if_timer:
jal vTaskSwitchContext
j processed_source
as_yet_unhandled:
// ebreak /* External interrupt? */
j as_yet_unhandled
test_if_external_interrupt:
addi t1, t1, 4 /* 0x80000007 + 4 = 0x8000000b == Machine external interrupt. */
bne a0, t1, is_exception /* Only thing left it can be. */
jal vPortHandleInterrupt
j processed_source
is_exception:
ebreak
j is_exception
processed_source:
lw sp, pxCurrentTCB /* Load pxCurrentTCB. */
@ -219,5 +183,48 @@ processed_source:
addi sp, sp, CONTEXT_SIZE
mret
/*-----------------------------------------------------------*/
.align 8
xPortStartFirstTask:
la t0, vPortTrapHandler
csrw mtvec, t0
lw sp, pxCurrentTCB /* Load pxCurrentTCB. */
lw sp, 0( sp ) /* Read sp from first TCB member. */
lw x1, 0( sp ) /* Note for starting the scheduler the exception return address is used as the function return address. */
lw x5, 2 * WORD_SIZE( sp ) /* t0 */
lw x6, 3 * WORD_SIZE( sp ) /* t1 */
lw x7, 4 * WORD_SIZE( sp ) /* t2 */
lw x8, 5 * WORD_SIZE( sp ) /* s0/fp */
lw x9, 6 * WORD_SIZE( sp ) /* s1 */
lw x10, 7 * WORD_SIZE( sp ) /* a0 */
lw x11, 8 * WORD_SIZE( sp ) /* a1 */
lw x12, 9 * WORD_SIZE( sp ) /* a2 */
lw x13, 10 * WORD_SIZE( sp ) /* a3 */
lw x14, 11 * WORD_SIZE( sp ) /* a4 */
lw x15, 12 * WORD_SIZE( sp ) /* a5 */
lw x16, 13 * WORD_SIZE( sp ) /* a6 */
lw x17, 14 * WORD_SIZE( sp ) /* a7 */
lw x18, 15 * WORD_SIZE( sp ) /* s2 */
lw x19, 16 * WORD_SIZE( sp ) /* s3 */
lw x20, 17 * WORD_SIZE( sp ) /* s4 */
lw x21, 18 * WORD_SIZE( sp ) /* s5 */
lw x22, 19 * WORD_SIZE( sp ) /* s6 */
lw x23, 20 * WORD_SIZE( sp ) /* s7 */
lw x24, 21 * WORD_SIZE( sp ) /* s8 */
lw x25, 22 * WORD_SIZE( sp ) /* s9 */
lw x26, 23 * WORD_SIZE( sp ) /* s10 */
lw x27, 24 * WORD_SIZE( sp ) /* s11 */
lw x28, 25 * WORD_SIZE( sp ) /* t3 */
lw x29, 26 * WORD_SIZE( sp ) /* t4 */
lw x30, 27 * WORD_SIZE( sp ) /* t5 */
lw x31, 28 * WORD_SIZE( sp ) /* t6 */
addi sp, sp, CONTEXT_SIZE
csrs mstatus, 8 /* Enable machine interrupts. */
ret
/*-----------------------------------------------------------*/