rp2040

commit b6befe55d289bcee8a73e339af2e0a4093de7aee
parent 8f94806cfd789d3aca81d1efa6c5588e253b7474
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Sat, 24 Feb 2024 09:52:24 +0900

implement systick interrupt

Diffstat:
M
ex3/main.s
 | 
61
+++++++++++++++++++++++++++++++++++++++++++++++++++++--------
M
ex3/memmap.ld
 | 
7
+------

2 files changed, 54 insertions(+), 14 deletions(-)
diff --git a/ex3/main.s b/ex3/main.s
@@ -1,12 +1,6 @@
 .cpu cortex-m0plus
 .thumb
 
-	.section .rodata
-	.global vectors
-vectors:
-	.word 0x20040000 // initial SP
-	.word (reset+1)  // entry point
-
 	.section .text
 reset:
 	// unreset gpio, pll_sys, uart0
@@ -97,14 +91,22 @@ wait_vco:
 	ldr r1, =0xe018
 	str r0, [r3, r1] // M0PLUS: SYST_CVR
 	// set reset value
-	ldr r0, =0xf423f // 1 sec
+	ldr r0, =0xf23f // 1 sec
 	ldr r1, =0xe014
 	str r0, [r3, r1] // M0PLUS: SYST_RVR
 	// enable systick timer
 	sub r1, r1, #4
-	mov r0, #1
+	ldr r0, =(1 << 1 | 1) // TICKINT | ENABLE
 	str r0, [r3, r1] // M0PLUS: SYST_CSR
 
+	// setup NMI
+	ldr r3, syscfg_base
+	mov r0, #1
+	lsl r0, #14
+	str r0, [r3, #0] // SYSCFG: PROC0_NMI_MASK
+
+	bl int_systick
+
 	ldr r4, ppb_base
 	ldr r5, =0xe018
 loop:
@@ -112,10 +114,31 @@ loop:
 	bl putbyte
 	ldr r0, [r4, r5] // M0PLUS: SYST_CVR
 	bl printh
+	ldr r0, ='\n'
+	bl putbyte
+	ldr r0, ='\r'
+	bl putbyte
+	mov r0, sp
+	bl printh
+	ldr r0, ='\n'
+	bl putbyte
+	wfi
 	b loop
 
 // functions
 
+int_systick:
+	push {lr}
+	ldr r0, ='\r'
+	bl putbyte
+	ldr r3, ppb_base
+	ldr r1, =0xe010
+	ldr r0, [r3, r1] // SYSCFG: PROC0_NMI_MASK
+	bl printh
+	ldr r0, ='\n'
+	bl putbyte
+	pop {pc}
+
 	// print r0 in hex for debugging.
 printh:
 	push {r4, r5, r6, r7, lr}
@@ -229,6 +252,8 @@ atomic_set:
 	.word 0x00002000
 atomic_clr:
 	.word 0x00003000
+syscfg_base:
+	.word 0x40004000
 clocks_base:
 	.word 0x40008000
 resets_base:
@@ -245,3 +270,23 @@ sio_base:
 	.word 0xd0000000
 ppb_base:
 	.word 0xe0000000
+
+	.align 8
+	.global vectors
+vectors:
+	.word 0x20040000 // 0 initial SP
+	.word (reset+1)  // 1 entry point
+	.word (reset+1)  // 2
+	.word (reset+1)  // 3
+	.word (reset+1)  // 4
+	.word (reset+1)  // 5
+	.word (reset+1)  // 6
+	.word (reset+1)  // 7
+	.word (reset+1)  // 8
+	.word (reset+1)  // 9
+	.word (reset+1)  // 10
+	.word (reset+1)  // 11
+	.word (reset+1)  // 12
+	.word (reset+1)  // 13
+	.word (reset+1)  // 14
+	.word (int_systick+1)  // 15 systick
diff --git a/ex3/memmap.ld b/ex3/memmap.ld
@@ -1,7 +1,6 @@
 MEMORY
 {
-	FLASH(rx) : ORIGIN = 0x10000000, LENGTH = 1m
-	VTOR(rx)  : ORIGIN = 0x10100000, LENGTH = 1m
+	FLASH(rx) : ORIGIN = 0x10000000, LENGTH = 2m
 	SRAM(rwx) : ORIGIN = 0x20000000, LENGTH = 264k
 }
 
@@ -15,9 +14,5 @@ SECTIONS
 	.text : {
 		*(.text)
 	} > FLASH
-
-	.rodata : {
-		*(.rodata)
-	} > VTOR
 }