initcalls: Add initial implementation

Create simple serial subsystem which makes use of initcalls, and convert
existing serial drivers to its use.

drivers/kernel.mk

@@ -3,6 +3,9 @@ SUBDIRS :=
 
 include $(BASEDIR)/header.mk
 
+OBJS_$(d) := \
+	$(d)/serial.o
+
 OBJS_$(d)_$(CONFIG_VEXPRESS_A9) := \
 	$(d)/pl011.o \
 	$(d)/pl111.o
@@ -15,6 +18,6 @@ OBJS_$(d)_$(CONFIG_RPI) := \
 	$(d)/bcm2835_mailbox.o \
 	$(d)/bcm2835_videocore.o
 
-KOBJS += $(OBJS_$(d)_y)
+KOBJS += $(OBJS_$(d)) $(OBJS_$(d)_y)
 
 include $(BASEDIR)/footer.mk

drivers/pi_mini_uart.c

@@ -18,8 +18,11 @@
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <init.h>
 #include <types.h>
 
+#include <drivers/serial.h>
+
 #define VC_MMU_IO_OFFSET(addr) (addr - 0x7E000000 + 0x20000000)
 
 /* Auxiliary IO registers (includes both mini-UART and SPI) */
@@ -57,7 +60,7 @@
 #define GPPUD VC_MMU_IO_OFFSET(0x7E200094)
 #define GPPUDCLK0 VC_MMU_IO_OFFSET(0x7E200098)
 
-void mini_uart_init() {
+void mini_uart_device_init() {
 	uint32 aux_enables;
 	uint32 gpfsel1;
 	unsigned int i;
@@ -96,10 +99,23 @@ void mini_uart_init() {
 	*(uint32 *)AUX_MU_CNTL_REG = 2; //enable TX
 }
 
-void mini_uart_putc(char c) {
+int mini_uart_putc(char c) {
 	/* Wait until the serial buffer is empty */
 	while (!(*(volatile uint32*)AUX_MU_LSR_REG & MINI_UART_TX_EMPTY));
 
 	/* When it's empty, write our character */
 	*(volatile uint32*)AUX_MU_IO_REG = c;
+
+	return 0;
 }
+
+struct serial_dev mini_uart_dev = {
+	.putc = &mini_uart_putc
+};
+
+void mini_uart_init() {
+	mini_uart_device_init();
+	serial_register_device(&mini_uart_dev);
+}
+
+early_initcall(mini_uart_init);

drivers/pl011.c

@@ -18,17 +18,31 @@
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <init.h>
+#include <drivers/serial.h>
 #include <types.h>
 
 #define PL011_SERIAL_BASE 0x10009000
 #define PL011_SERIAL_FLAG_REGISTER 0x18
 #define PL011_SERIAL_BUFFER_FULL (1 << 5)
 
-void pl011_putc(char c)
+int pl011_putc(char c)
 {
 	/* Wait until the serial buffer is empty */
 	while (*(volatile uint32*)(PL011_SERIAL_BASE + PL011_SERIAL_FLAG_REGISTER) & (PL011_SERIAL_BUFFER_FULL));
 
 	/* When it's empty, put our character at the base */
 	*(volatile uint32*)PL011_SERIAL_BASE = c;
+
+	return 0;
 }
+
+struct serial_dev pl011_dev = {
+	.putc = &pl011_putc
+};
+
+void pl011_init() {
+	serial_register_device(&pl011_dev);
+}
+
+early_initcall(pl011_init);

drivers/serial.c

@@ -0,0 +1,40 @@
+/*
+    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
+
+    This file is part of Aedrix.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <init.h>
+#include <drivers/serial.h>
+
+struct serial_dev *first_serial_dev;
+
+int serial_register_device(struct serial_dev *sdev) {
+	if (!first_serial_dev)
+		first_serial_dev = sdev;
+	return 0;
+}
+
+struct serial_dev *serial_first_device() {
+	return first_serial_dev;
+}
+
+void serial_init() {
+	first_serial_dev = 0;
+}
+
+driversubsys_initcall(serial_init);

include/console.h

@@ -22,6 +22,6 @@
 #define CONSOLE_H
 
 void console_init(struct fb *f);
-void console_putc(char c);
+int console_putc(char c);
 
 #endif /* CONSOLE_H */

include/drivers/serial.h

@@ -0,0 +1,27 @@
+/*
+    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
+
+    This file is part of Aedrix.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+struct serial_dev {
+	//TODO add more functions and attributes here
+	int (*putc)(char);
+};
+
+int serial_register_device(struct serial_dev *sdev);
+struct serial_dev *serial_first_device();

include/init.h

@@ -0,0 +1,34 @@
+/*
+    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
+
+    This file is part of Aedrix.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+void init_earlyinitcalls();
+void init_initcalls();
+
+struct initcall_func {
+	void (*fptr)();
+};
+
+#define _initcall(level_name, level, func) struct initcall_func func##_##level##_initcall \
+	__attribute__ ((section ("." level_name "initcalls"))) = { func }
+
+/* The actual calls to be used externally */
+#define early_initcall(func) _initcall("early", 0, func)
+#define driversubsys_initcall(func) _initcall("driversubsys", 1, func)
+#define device_initcall(func) _initcall("device", 2, func)

include/print.h

@@ -21,8 +21,8 @@
 #ifndef PRINT_H
 #define PRINT_H
 
-void print_init(void (*putc)(char));
+void print_init(int (*putc)(char));
 int print(char *fmt, ...);
-int print_func(void (putcf)(char), char *fmt, ...);
+int print_func(int (putcf)(char), char *fmt, ...);
 
 #endif /* PRINT_H */

kernel/console.c

@@ -123,17 +123,17 @@ void console_newline() {
 	}
 }
 
-void console_putc(char c) {
+int console_putc(char c) {
 	char *console_buffer_end = console_buffer + chars_per_line * lines;
 	char *write_char_at;
 
 	switch (c) {
 		case '\n':
 			console_newline();
-			return;
+			return 0;
 		case '\r':
 			curr_char = 0;
-			return;
+			return 0;
 		default:
 			break;
 	}
@@ -148,4 +148,6 @@ void console_putc(char c) {
 	*write_char_at = c;
 
 	console_char_to_fb(c, curr_char++, curr_line);
+
+	return 0;
 }

kernel/init.c

@@ -0,0 +1,37 @@
+/*
+    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
+
+    This file is part of Aedrix.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <types.h>
+#include <print.h>
+
+extern uint32 early_initcalls_start, early_initcalls_end;
+extern uint32 initcalls_start, initcalls_end;
+
+void init_earlyinitcalls() {
+	void (**initcall)();
+	for (initcall = (void (**)()) &early_initcalls_start; initcall < (void (**)())&early_initcalls_end; initcall++)
+		(*initcall)();
+}
+
+void init_initcalls() {
+	void (**initcall)();
+	for (initcall = (void (**)()) &initcalls_start; initcall < (void (**)())&initcalls_end; initcall++)
+		(*initcall)();
+}

kernel/kernel.mk

@@ -7,6 +7,7 @@ OBJS_$(d) := $(d)/atags.o \
 	$(d)/console.o \
 	$(d)/font.o \
 	$(d)/framebuffer.o \
+	$(d)/init.o \
 	$(d)/kmalloc.o \
 	$(d)/list.o \
 	$(d)/math.o \

kernel/print.c

@@ -23,22 +23,23 @@
 
 /* This function exists solely so crashes don't happen if putc() gets
  * called before it is initialized. */
-void putc_initial(char c) {
+int putc_initial(char c) {
 	(void)c;
+	return 0;
 }
-void (*print_putc)(char) = &putc_initial;
+int (*print_putc)(char) = &putc_initial;
 
-void print_init(void (*putcfn)(char)) {
+void print_init(int (*putcfn)(char)) {
 	if (putcfn)
 		print_putc = putcfn;
 }
  
-void puts(void (*putc)(char), const char *s)
+void puts(int (*putc)(char), const char *s)
 {
     while (*s) putc (*s++);
 }
 
-void puti(void (*putc)(char), int i)
+void puti(int (*putc)(char), int i)
 {
 	unsigned int left;
 	char buf[1 << (sizeof(int)*8) / 10];
@@ -64,7 +65,7 @@ void puti(void (*putc)(char), int i)
 		putc(*p);
 }
 
-void putx(void (*putc)(char), unsigned int i) {
+void putx(int (*putc)(char), unsigned int i) {
 	int j;
 
 	puts(putc, "0x");
@@ -78,7 +79,7 @@ void putx(void (*putc)(char), unsigned int i) {
 	}
 }
 
-void putb(void (*putc)(char), unsigned int i) {
+void putb(int (*putc)(char), unsigned int i) {
 	int j;
 
 	puts(putc, "0b");
@@ -88,7 +89,7 @@ void putb(void (*putc)(char), unsigned int i) {
 	}
 }
 
-int _print(void (*putc)(char), char *fmt, va_list arg) {
+int _print(int (*putc)(char), char *fmt, va_list arg) {
 	char *c;
 	for (c = fmt; *c; c++) {
 		if (*c == '%') {
@@ -138,7 +139,7 @@ int print(char *fmt, ...) {
 }
 
 
-int print_func(void (*putc)(char), char *fmt, ...) {
+int print_func(int (*putc)(char), char *fmt, ...) {
 	int ret;
 	va_list arg;
 

kernel/start_kernel.c

@@ -19,6 +19,7 @@
  */
 
 #include <atags.h>
+#include <init.h>
 #include <kmalloc.h>
 #include <mmu.h>
 #include <mm.h>
@@ -26,13 +27,13 @@
 #include <framebuffer.h>
 #include <console.h>
 
+#include <drivers/serial.h>
+
 #ifdef CONFIG_VEXPRESS_A9
-#include <drivers/pl011.h>
 #include <drivers/pl111.h>
 #endif
 
 #ifdef CONFIG_RPI
-#include <drivers/pi_mini_uart.h>
 #include <drivers/bcm2835_videocore.h>
 #endif
 
@@ -56,74 +57,11 @@ void video_init(void) {
 #endif
 }
 
-void test_mm() {
-	struct page *p, *q;
+void serial_console_init() {
+	struct serial_dev *sdev = serial_first_device();
 
-	print("\ntest_mm():\n");
-
-	p = mm_get_free_pages(0);
-	if (p)
-		print("%x, %x\n", p, p->address);
-	else
-		print("Error: failed to allocate memory for p\n");
-
-	q = mm_get_free_pages(4);
-	if (q)
-		print("%x, %x\n", q, q->address);
-	else
-		print("Error: failed to allocate memory for q\n");
-
-	mm_put_free_pages(p);
-	mm_put_free_pages(q);
-
-	q = mm_get_free_pages(1);
-	if (q)
-		print("%x, %x\n", q, q->address);
-	else
-		print("Error: failed to allocate memory for q\n");
-
-	p = mm_get_free_pages(0);
-	if (p)
-		print("%x, %x\n", p, p->address);
-	else
-		print("Error: failed to allocate memory for p\n");
-	mm_put_free_pages(p);
-	mm_put_free_pages(q);
-
-}
-
-void test_kmalloc() {
-	void *a, *b, *c, *d;
-
-	print("\ntest_kmalloc():\n");
-
-	a = kmalloc(4);
-	print("a: %x\n", a);
-	b = kmalloc(13);
-	print("b: %x\n", b);
-	c = kmalloc(4);
-	print("c: %x\n", c);
-	d = kmalloc(25);
-	print("d: %x\n", d);
-
-	kfree(c);
-	kfree(b);
-	kfree(a);
-	kfree(d);
-
-	a = kmalloc(13);
-	print("a: %x\n", a);
-	b = kmalloc(4);
-	print("b: %x\n", b);
-	c = kmalloc(25);
-	print("c: %x\n", c);
-	d = kmalloc(7);
-	print("d: %x\n", d);
-}
-
-void test_memory() {
-	test_mm();
-	test_kmalloc();
+	if (sdev)
+		print_init(sdev->putc);
 }
 
 void kmalloc_init();
@@ -135,14 +73,9 @@ int main(void) {
 	//setup MMU
 	mmu_reinit();
 
-	//initialize the serial console
-#ifdef CONFIG_VEXPRESS_A9
-	print_init(&pl011_putc);
-#endif
-#ifdef CONFIG_RPI
-	mini_uart_init();
-	print_init(&mini_uart_putc);
-#endif
+	init_earlyinitcalls();
+
+	serial_console_init();
 
 	//setup memory
 	mm_init();
@@ -159,7 +92,7 @@ int main(void) {
 		declare_memory_region(lower, upper);
 	} while (!atags_next_mem_region(&atags));
 
-	test_memory();
+	init_initcalls();
 
 	video_init();
 	console_init(&myfb);

link.ld

@@ -2,9 +2,18 @@ ENTRY (start)
 
 SECTIONS
 {
-    . = 0x80100000;
-    .text : { *(.text*) *(.rodata*) }
-    .data : { *(.data*) }
-    .bss : { *(.bss*) *(COMMON*) }
-    kernel_end = .;
+	. = 0x80100000;
+	.text : { *(.text*) *(.rodata*) }
+	.init : {
+		early_initcalls_start = .;
+		*(.earlyinitcalls*)
+		early_initcalls_end = .;
+		initcalls_start = .;
+		*(.driversubsysinitcalls*)
+		*(.deviceinitcalls*)
+		initcalls_end = .;
+	}
+	.data : { *(.data*) }
+	.bss : { *(.bss*) *(COMMON*) }
+	kernel_end = .;
 }