fix: wake RISC-V secondary idle IPIs and link integ percpu/SMP

- Kernel trampoline enables MIE so CPU1 idle takes CLINT MSIP resched IPIs
- integ_kernel pulls percpu/klock/wcet + arch smp.c (fixes ctx_early_tricore)

Author: uLipe

arch/riscv/ctx_switch.S

@@ -57,6 +57,12 @@ ulmk_arch_ctx_switch:
 	.global _ulmk_thread_trampoline_m
 	.type _ulmk_thread_trampoline_m, @function
 _ulmk_thread_trampoline_m:
+	/*
+	 * Kernel threads (idle) inherit MIE=0 from the prior trap/syscall
+	 * path.  Without enabling, secondary-hart idle never takes CLINT
+	 * MSIP IPIs and remote affinity threads stall forever.
+	 */
+	csrsi   mstatus, 0x8            /* set MIE */
 	mv      a0, s0                  /* entry — 1st arg to common entry */
 	mv      a1, s1                  /* arg   — 2nd arg to common entry */
 	tail    ulmk_user_thread_entry  /* jump: common entry never returns */

kernel/kernel_main.c

@@ -224,7 +224,8 @@ void ulmk_kern_secondary_main(void)
 	 * online + secondary_mark_ready happen inside ulmk_sched_start() only
 	 * after current is set — otherwise a remote IPI can run dispatch with
 	 * current==NULL (drops the kick) and clear the soft mailbox forever.
-	 * Leave IE clear until the RFE into idle (PIE in the fabricated CSA).
+	 * Arch idle entry must accept IPIs (RISC-V kernel trampoline enables
+	 * MIE; TriCore idle CSA has PIE=1 on RFE).
 	 */
 	ulmk_printk("ulmk: CPU%u sched_start\n", (unsigned)cpu);
 	(void)cpu;

tests/arch/riscv.mk

@@ -22,6 +22,7 @@ ARCH_LDFLAGS := -march=rv32imac_zicsr_zifencei -mabi=ilp32
 ARCH_KERNEL_SRCS := \
 	$(ROOT)/arch/riscv/startup.S \
 	$(ROOT)/arch/riscv/arch.c \
+	$(ROOT)/arch/riscv/smp.c \
 	$(ROOT)/arch/riscv/irq.c \
 	$(ROOT)/arch/riscv/irq_clint.c \
 	$(ROOT)/arch/riscv/irq_clic.c \

tests/arch/tricore.mk

@@ -18,6 +18,7 @@ ARCH_LDFLAGS := -mcpu=tc39xx
 ARCH_KERNEL_SRCS := \
 	$(ROOT)/arch/tricore/startup.S \
 	$(ROOT)/arch/tricore/arch.c \
+	$(ROOT)/arch/tricore/smp.c \
 	$(ROOT)/arch/tricore/ctx_switch.S \
 	$(ROOT)/arch/tricore/vectors.S \
 	$(ROOT)/boards/qemu_tc3xx/qemu_printk_hook.c

tests/integ_kernel.mk

@@ -29,6 +29,8 @@ INTEG_KERNEL_SRCS ?= \
 	$(ROOT)/kernel/init/init.c \
 	$(ROOT)/kernel/kernel_main.c \
 	$(ROOT)/kernel/printk/ulmk_printk.c \
+	$(ROOT)/kernel/percpu/percpu.c \
+	$(ROOT)/kernel/percpu/klock.c \
 	$(ROOT)/kernel/sched/sched.c \
 	$(ROOT)/kernel/sched/fifo_rt.c \
 	$(ROOT)/kernel/sched/bitmap_rt.c \
@@ -39,6 +41,7 @@ INTEG_KERNEL_SRCS ?= \
 	$(ROOT)/kernel/ipc/ep.c \
 	$(ROOT)/kernel/notif/notif.c \
 	$(ROOT)/kernel/syscall/syscall_router.c \
+	$(ROOT)/kernel/syscall/syscall_wcet.c \
 	$(INTEG_KERNEL_STUB) \
 	$(INTEG_KERNEL_EXTRA_SRCS)