rp2040

commit fffa152122240112565655f51547ef6c5a6c0a57
parent d4782618cbd2c8cc737cba77a7fec5379b8d6bee
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Fri,  8 Mar 2024 09:17:35 +0900

fix bug where the tail of the program is not copied to sram

Diffstat:
M
ex3/Makefile
 | 
6
++++--
M
ex3/boot2.s
 | 
2
+-
M
ex3/main.c
 | 
16
+++++++++++++---
M
ex3/memmap.ld
 | 
10
+++++++++-
A
ex3/proc.s
 | 
19
+++++++++++++++++++

5 files changed, 46 insertions(+), 7 deletions(-)
diff --git a/ex3/Makefile b/ex3/Makefile
@@ -10,6 +10,8 @@ ASFLAGS = $(MCPU)
 CFLAGS = $(MCPU) -mthumb -ffreestanding -nostartfiles -O0 -fpic -c
 LDFLAGS = --no-relax -nostdlib
 
+OBJS = boot2.o start.o main.o proc.o
+
 all: tools a.uf2
 
 clean:
@@ -22,8 +24,8 @@ clean:
 .c.o:
 	$(CC) $(CFLAGS) -o $@ $<
 
-a.elf: boot2.o start.o main.o memmap.ld
-	$(LD) $(LDFLAGS) -o $@ -T memmap.ld boot2.o start.o main.o
+a.elf: $(OBJS) memmap.ld
+	$(LD) $(LDFLAGS) -o $@ -T memmap.ld $(OBJS)
 
 a.bin: a.elf
 	$(OBJCOPY) -O binary a.elf $@
diff --git a/ex3/boot2.s b/ex3/boot2.s
@@ -11,7 +11,7 @@ boot2:
 	blx r2
 	blx r0
 
-	// clear sram contents
+	// Clear sram contents for debugging.
 	mov r0, #0
 	ldr r3, sram_base
 	ldr r4, sram_end
diff --git a/ex3/main.c b/ex3/main.c
@@ -1,14 +1,16 @@
 void init(void);
 int puts(char *);
-void printh(unsigned int);
+void printh(void *);
 void set_alarm(unsigned int);
 
+extern void *proc0;
+
 // A proc represents a process in execution.
 typedef struct proc {
 	// Id is the unique identifier of the process.
 	unsigned int id;
 	// R is the registers of the process with r[13] be sp, r[14] lr, r[15] pc.
-	unsigned int r[16];
+	void *r[16];
 } proc;
 
 // A proc_tab is the queue of waiting processes.
@@ -27,7 +29,15 @@ int
 main(void) {
 	init();
 
-	proc *p0 = (proc *)0x20001000, *p1 = (proc *) 0x20001100;
+	proc *p0 = (proc *) 0x20041000, *p1 = (proc *) 0x20041100; // sram5
+
+	p0->r[13] = (void *) 0x20000100; // sp
+	p0->r[14] = (void *) 0xdeadbeef; // lr
+	p0->r[15] = (void *) 0x20000000; // pc
+
+	p1->r[13] = (void *) 0x20000200; // sp
+	p1->r[14] = (void *) 0xdeadbeef; // lr
+	p1->r[15] = (void *) 0x20000100; // pc
 
 	return 0;
 }
diff --git a/ex3/memmap.ld b/ex3/memmap.ld
@@ -13,6 +13,7 @@ SECTIONS
 		*(.vectors)
 	} > FLASH
 	.text : {
+		kernel_start = .;
 		*(.text)
 	} > SRAM4 AT > FLASH
 	.data : {
@@ -20,8 +21,15 @@ SECTIONS
 	} > SRAM4 AT > FLASH
 	.rodata : {
 		*(.rodata)
+		kernel_end = .;
 	} > SRAM4 AT > FLASH
 	prog_start = LOADADDR(.text);
-	prog_size = SIZEOF(.text) + SIZEOF(.data) + SIZEOF(.rodata);
+	prog_size = kernel_end - kernel_start;
+	.proc0 0x20000000 : {
+		*(.proc0)
+	} > SRAM AT > FLASH
+	.proc1 0x20000100 : {
+		*(.proc1)
+	} > SRAM AT > FLASH
 }
 
diff --git a/ex3/proc.s b/ex3/proc.s
@@ -0,0 +1,19 @@
+	.section .proc0
+	.global proc0
+proc0:
+	ldr r0, msg0
+	bl puts
+	b proc0
+
+msg0:
+	.asciz "proc0"
+
+	.section .proc1
+	.global proc1
+proc1:
+	ldr r0, msg1
+	bl puts
+	b proc1
+
+msg1:
+	.asciz "proc1"