altos/lpc: Use separate interrupt stack

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/lpc/ao_arch_funcs.h b/src/lpc/ao_arch_funcs.h
index bc4c47ee..3cd873ec 100644
--- a/src/lpc/ao_arch_funcs.h
+++ b/src/lpc/ao_arch_funcs.h
@@ -208,4 +208,17 @@ ao_spi_init(void);
 		}							\
 	} while (0)
 
+#define HAS_ARCH_START_SCHEDULER	1
+
+static inline void ao_arch_start_scheduler(void) {
+	uint32_t	sp;
+	uint32_t	control;
+
+	asm("mrs %0,msp" : "=&r" (sp));
+	asm("msr psp,%0" : : "r" (sp));
+	asm("mrs %0,control" : "=&r" (control));
+	control |= (1 << 1);
+	asm("msr control,%0" : : "r" (control));
+}
+
 #endif /* _AO_ARCH_FUNCS_H_ */