rp2040

commit ebda2e2c7c3a8e48020c15d06b46a4e7528b1eff
parent 88a4d0b9ff7e004c7e4cf45b60c5f051bed29eab
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Fri, 23 Feb 2024 13:31:46 +0900

worked, although timer is slow after reset

Diffstat:
M
ex3/boot2.s
 | 
4
+---
M
ex3/main.s
 | 
27
++++++++++++++++++++-------
M
ex3/memmap.ld
 | 
2
+-

3 files changed, 22 insertions(+), 11 deletions(-)
diff --git a/ex3/boot2.s b/ex3/boot2.s
@@ -11,7 +11,7 @@ setup_xip:
 	blx r2
 	blx r0
 
-	ldr r0, flash_main
+	ldr r0, =vectors
 	ldr r1, m0plus_vtor 
 	str r0, [r1, #0] // M0PLUS: VTOR
 	ldr r1, [r0, #4] // entry point
@@ -22,8 +22,6 @@ setup_xip:
 	.align 2
 rom_base:
 	.word 0x00000000
-flash_main:
-	.word 0x10000000 + 0x100
 m0plus_vtor:
 	.word 0xe0000000 + 0xed08
 literals:
diff --git a/ex3/main.s b/ex3/main.s
@@ -2,6 +2,7 @@
 .thumb
 
 	.section .vectors
+	.global vectors
 vectors:
 	.word 0x20040000 // initial SP
 	.word (reset+1)  // entry point
@@ -59,17 +60,19 @@ wait_vco:
 	mov r0, #8 // POSTDIVPD
 	str r0, [r3, r1] // PLL: PWR
 
-	// set system clock clksrc_pll_sys
 	ldr r3, clocks_base
+	// set clk_ref to xosc
+	mov r0, #2
+	ldr r1, atomic_set
+	add r1, r1, #0x30
+	str r0, [r3, r1] // CLOCKS: CLK_REF_CTRL
+	// set system clock clksrc_pll_sys
 	ldr r0, =(0x0 << 5 | 0x1)
 	str r0, [r3, #0x3c] // CLOCKS: CLK_SYS_CTRL
 	// enable clk_peri
 	mov r0, #1
 	lsl r0, r0, #11
 	str r0, [r3, #0x48] // CLOCKS: CLK_PERI_CTRL
-	// set clk_ref to xosc
-	mov r0, #2
-	str r0, [r3, #0x30] // CLOCKS: CLK_REF_CTRL
 
 	// setup uart0
 	ldr r3, uart0_base
@@ -101,14 +104,24 @@ wait_vco:
 	sub r1, r1, #4
 	mov r0, #1
 	str r0, [r3, r1] // M0PLUS: SYST_CSR
+/*
+debug:
+	ldr r0, ='\r'
+	bl putbyte
+	ldr r4, =0x20000000
+	ldr r0, [r4, #0]
+	bl printh
+	ldr r0, ='\n'
+	bl putbyte
+*/
 
-	mov r4, r3
+	ldr r4, ppb_base
 	ldr r5, =0xe018
 loop:
-	ldr r0, [r4, r5] // M0PLUS: SYST_CVR
-	bl printh
 	ldr r0, ='\r'
 	bl putbyte
+	ldr r0, [r4, r5] // M0PLUS: SYST_CVR
+	bl printh
 	b loop
 
 // functions
diff --git a/ex3/memmap.ld b/ex3/memmap.ld
@@ -1,6 +1,6 @@
 MEMORY
 {
-	FLASH(rx) : ORIGIN = 0x10000000, LENGTH = 2048k
+	FLASH(rx) : ORIGIN = 0x10000000, LENGTH = 2m
 	SRAM(rwx) : ORIGIN = 0x20000000, LENGTH = 264k
 }