rp2040

commit 07d07fe2aeaee6b1cbda4b132c08aa68a483b4f7
parent e15aac2f4537c9045462db34543a5bd779dc8520
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Mon, 27 Mar 2023 10:44:22 +0900

try to use core1

Diffstat:
M
as.s
 | 
95
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
M
main.c
 | 
16
+++++++++-------

2 files changed, 102 insertions(+), 9 deletions(-)
diff --git a/as.s b/as.s
@@ -121,8 +121,6 @@ pll_lock:
 
 	pop {pc}
 
-// functions
-
 unreset:
 	// unreset subsystems specified by r0
 	// args: bit mask to specify the subsystems to unreset
@@ -144,6 +142,99 @@ reset_chk:
 	beq reset_chk
 	bx lr
 
+	.global mcfork // int mcfork(void)
+mcfork:
+	push {r4, lr}
+	ldr r0, =0x20000800
+	mov r1, lr
+	str r1, [r0, #0]
+mcfork_retry:
+	bl mc_fifo_drain
+	mov r0, #0
+	bl mc_fifo_send
+	bl mc_fifo_recv
+	cmp r0, #0
+	bne mcfork_retry
+
+	bl mc_fifo_drain
+	mov r0, #0
+	bl mc_fifo_send
+	bl mc_fifo_recv
+	cmp r0, #0
+	bne mcfork_retry
+
+	bl led_p0
+
+	mov r0, #1
+	bl mc_fifo_send
+	bl mc_fifo_recv
+	cmp r0, #1
+	bne mcfork_retry
+
+	bl led_p1
+
+	ldr r0, =0x10000100 // __vectors
+	mov r4, r0
+	bl mc_fifo_send
+	bl mc_fifo_recv
+	cmp r0, r4
+	bne mcfork_retry
+
+	ldr r0, =0x200007fc // initial sp
+	mov r4, r0
+	bl mc_fifo_send
+	bl mc_fifo_recv
+	cmp r0, r4
+	bne mcfork_retry
+
+
+	adr r0, mcfork_ent
+	add r0, r0, #1 // thumb mode
+	mov r4, r0
+	bl mc_fifo_send
+	bl mc_fifo_recv
+	cmp r0, r4
+	bne mcfork_retry
+	.align 2
+mcfork_ent:
+	pop {r4, pc}
+
+
+mc_fifo_drain:
+	ldr r0, sio_base
+mc_fifo_not_empty:
+	ldr r1, [r0, #0x50] // SIO_FIFO_ST
+	mov r2, #1
+	and r1, r2
+	bne mc_fifo_empty
+	ldr r3, [r0, #0x58] // SIO_FIFO_RD
+	b mc_fifo_not_empty
+mc_fifo_empty:
+	sev
+	bx lr
+
+mc_fifo_send:
+	ldr r1, sio_base
+mc_fifo_full:
+	ldr r2, [r1, #0x50] // SIO_FIFO_ST
+	mov r3, #2
+	and r2, r3
+	beq mc_fifo_full
+	str r0, [r1, #0x54] // SIO_FIFO_WR
+	sev
+	bx lr
+
+mc_fifo_recv:
+	ldr r1, sio_base
+	ldr r2, [r1, #0x50] // SIO_FIFO_ST
+	mov r3, #1
+	and r2, r3
+	bne mc_fifo_redy
+	wfe
+mc_fifo_redy:
+	ldr r0, [r1, #0x58] // SIO_FIFO_RD
+	bx lr
+
 	.global putchar
 putchar:
 uart0_write:
diff --git a/main.c b/main.c
@@ -1,13 +1,15 @@
 void
 main(void)
 {
-	char *s = "unko\n";
-	char *c;
+	int cpuid;
 	init();
-	while(1) {
-		for (c = s; *c != '\0'; c++) {
-			putchar(*c);
-		}
-		delay();
+	print("unko\n");
+	cpuid = mcfork();
+	if (cpuid == 0) {
+		print("cpu0\n");
+	} else if (cpuid == 1) {
+		print("cpu1\n");
+	} else {
+		print("something wrong\n");
 	}
 }