Added basic awareness of kernel size/bounds

7 files changed, 103 insertions, 42 deletions

diff --git a/Makefile b/Makefile
index 339f63e..0771908 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ CC		:= gcc
 AR		:= ar
 CPP		:= cpp
 OBJCOPY		?= objcopy
-OBJCOPY_FLAGS	?= -Obinary
+OBJCOPY_FLAGS	?= -Obinary --set-section-flags .bss=alloc,load,contents
 
 COMMON_SOURCES	!= echo common/*.c
 KERNEL_SOURCES	!= echo kernel/*.c $(COMMON_SOURCES)
@@ -36,29 +36,34 @@ GENELF		= $(CROSS_COMPILE)$(CC) $(DEBUGFLAGS)\
 
 GENLINK		= $(CROSS_COMPILE)$(CPP) $(DEPFLAGS) $(INCLUDE_FLAGS)
 STRIPLINK	= sed -n '/^[^\#]/p'
+KERN_SIZE	= wc -c kernel.bin | cut -d ' ' -f 1
+KERN_INFO	= sed "s/<KERNEL_SIZE>/$$($(KERN_SIZE))/"
 
 KERNEL_LINK	:= arch/$(ARCH)/conf/kernel-link
 INIT_LINK	:= arch/$(ARCH)/conf/init-link
 
 KERNEL_OBJECTS	!= ./scripts/gen-deps --kern "$(KERNEL_SOURCES)"
 INIT_OBJECTS	!= ./scripts/gen-deps --init "$(INIT_SOURCES)"
-KERNEL_LD	!= ./scripts/gen-deps --link "$(KERNEL_LINK).S"
-INIT_LD		!= ./scripts/gen-deps --link "$(INIT_LINK).S"
+KERNEL_LD	!= ./scripts/gen-deps --kern-link "$(KERNEL_LINK).S"
+INIT_LD		!= ./scripts/gen-deps --init-link "$(INIT_LINK).S"
 
 include deps.mk
 
-apos.bin: kernel.elf init.elf
-	$(CROSS_COMPILE)$(OBJCOPY) $(OBJCOPY_FLAGS) kernel.elf kernel.bin
-	$(CROSS_COMPILE)$(OBJCOPY) $(OBJCOPY_FLAGS) init.elf init.bin
-	./scripts/gen-padding 4096 init.bin
+apos.bin: kernel.bin init.bin
 	cat init.bin kernel.bin > $@
 
 kernel.elf: $(KERNEL_OBJECTS) $(KERNEL_LD)
 	$(GENELF) -T $(KERNEL_LD) $(KERNEL_OBJECTS) -o $@
 
-init.elf: $(INIT_OBJECTS) $(INIT_LD)
+init.elf: kernel.bin $(INIT_OBJECTS) $(INIT_LD)
 	$(GENELF) -T $(INIT_LD) $(INIT_OBJECTS) -o $@
 
+kernel.bin: kernel.elf
+	$(CROSS_COMPILE)$(OBJCOPY) $(OBJCOPY_FLAGS) $< $@
+
+init.bin: init.elf
+	$(CROSS_COMPILE)$(OBJCOPY) $(OBJCOPY_FLAGS) $< $@
+
 clean:
 	$(RM) -r $(CLEANUP)
 
diff --git a/TODO.txt b/TODO.txt
index 7782709..1d84441 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -10,3 +10,4 @@
 + Jump to vmem
 + Mark fdt, reserved mem, kernel, init and initrd in vmem. Remember to remove
 init from vmem when jumping to vmem
++ Figure out best way to tell the init how large out kernel is
diff --git a/arch/riscv/conf/init-link.S b/arch/riscv/conf/init-link.S
index 2bb904b..86e692e 100644
--- a/arch/riscv/conf/init-link.S
+++ b/arch/riscv/conf/init-link.S
@@ -5,8 +5,29 @@ ENTRY(_start)
 
 SECTIONS {
 	. = ABSOLUTE(PM_KERN);
+	__init_start = .;
+
+	/* objcopy only copies these three sections (as far as I'm aware) into the
+	   produces binary, so __init_end should point to the correct location in the
+	   final binary
+	 */
 	.text ALIGN(4K) : AT(0) {
 		*(.init.start)
 		*(.text*);
 	}
+
+	.rodata : {
+		*(.rodata*)
+	}
+
+	.data : {
+		*(.data*)
+	}
+
+	.bss : {
+		*(.bss*) *(COMMON)
+	}
+
+	__kernel_size = <KERNEL_SIZE>;
+	__init_end = . ;
 }
diff --git a/arch/riscv/conf/kernel-link.S b/arch/riscv/conf/kernel-link.S
index 4592086..1ccdc77 100644
--- a/arch/riscv/conf/kernel-link.S
+++ b/arch/riscv/conf/kernel-link.S
@@ -5,8 +5,24 @@ ENTRY(main)
 
 SECTIONS {
 	. = ABSOLUTE(VM_KERN);
+	__kernel_start = .;
+
 	.text ALIGN(4K) : AT(0) {
 		*(.kernel.start);
 		*(.text*);
 	}
+
+	.rodata : {
+		*(.rodata*)
+	}
+
+	.data : {
+		*(.data*)
+	}
+
+	.bss : {
+		*(.bss*) *(COMMON)
+	}
+
+	__kernel_end = .;
 }
diff --git a/arch/riscv/init/init.c b/arch/riscv/init/init.c
index 1ec19a4..ee4a130 100644
--- a/arch/riscv/init/init.c
+++ b/arch/riscv/init/init.c
@@ -10,7 +10,7 @@
 #include <csr.h>
 #include <vmap.h>
 
-struct mem_layout {
+struct pmem_layout {
 	pm_t base;
 	pm_t top;
 };
@@ -28,9 +28,10 @@ static struct cell_info get_cellinfo(void *fdt, int offset)
 	};
 
 	return ret;
+
 }
 
-static struct mem_layout get_memlayout(void *fdt)
+static struct pmem_layout get_memlayout(void *fdt)
 {
 	struct cell_info ci = get_cellinfo(fdt, 0);
 
@@ -38,24 +39,17 @@ static struct mem_layout get_memlayout(void *fdt)
 	uint8_t *mem_reg =
 		(uint8_t *) fdt_getprop(fdt, mem_offset, "reg", NULL);
 
-	pm_t base;
 	/* if riscv128 comes around we will probably see addr_cells == 4, but
 	 * I'm not too concerned about it at the moment */
-	if (ci.addr_cells == 2) {
-		base = fdt64_to_cpu(*(fdt64_t *) mem_reg);
-		mem_reg += sizeof(fdt64_t);
-	} else {
-		base = fdt32_to_cpu(*(fdt32_t *) mem_reg);
-		mem_reg += sizeof(fdt32_t);
-	}
+	pm_t base = fdt_load_int_ptr(pm_t, ci.addr_cells, mem_reg);
 
-	pm_t top;
-	if (ci.size_cells == 2)
-		top = fdt64_to_cpu(*(fdt64_t *) mem_reg) + base;
+	if(ci.addr_cells == 2)
+		mem_reg += sizeof(fdt64_t);
 	else
-		top = fdt32_to_cpu(*(fdt32_t *) mem_reg) + base;
+		mem_reg += sizeof(fdt32_t);
 
-	struct mem_layout ret = { base, top };
+	pm_t top = fdt_load_int_ptr(pm_t, ci.size_cells, mem_reg) + base;
+	struct pmem_layout ret = { base, top };
 	return ret;
 }
 
@@ -74,7 +68,8 @@ static enum serial_dev_t serial_dev_enum(const char *dev_name)
 static void init_debug(void *fdt)
 {
 	int chosen_offset = fdt_path_offset(fdt, "/chosen");
-	const char *stdout = fdt_getprop(fdt, chosen_offset, "stdout-path", 0);
+	const char *stdout = fdt_getprop(fdt, chosen_offset,
+			"stdout-path", NULL);
 
 	int stdout_offset = fdt_path_offset(fdt, stdout);
 
@@ -89,10 +84,7 @@ static void init_debug(void *fdt)
 	void *reg_ptr = (void *)fdt_getprop(fdt, stdout_offset, "reg", NULL);
 
 	void *uart_ptr = 0;
-	if (ci.addr_cells == 2)
-		uart_ptr = (void *)(pm_t)fdt64_to_cpu(*(fdt64_t *) reg_ptr);
-	else
-		uart_ptr = (void *)(pm_t)fdt32_to_cpu(*(fdt32_t *) reg_ptr);
+	uart_ptr = (void *)fdt_load_int_ptr(pm_t, ci.addr_cells, reg_ptr);
 
 	dbg_init(uart_ptr, dev);
 }
@@ -101,46 +93,56 @@ static void init_debug(void *fdt)
 #define init_debug(...)
 #endif
 
-/* TODO: these */
-static pm_t get_kerneltop(void *fdt)
+static pm_t get_kerneltop()
 {
-	return 0;
+	/* interesting, for some reason if I define these to be just char
+	 * pointers I get some wacky values. Not sure why that would be, but
+	 * this works. */
+	extern char __init_end[], __kernel_size[];
+	return (pm_t)__init_end + (pm_t)__kernel_size;
 }
 
 static pm_t get_initrdtop(void *fdt)
 {
-	return 0;
+	int chosen_offset = fdt_path_offset(fdt, "/chosen");
+	struct cell_info ci = get_cellinfo(fdt, chosen_offset);
+
+	void *initrd_end_ptr = (void *)fdt_getprop(fdt, chosen_offset,
+			"linux,initrd-end", NULL);
+
+	return fdt_load_int_ptr(pm_t, ci.addr_cells, initrd_end_ptr);
 }
 
 static pm_t get_fdttop(void *fdt)
 {
-	return 0;
+	const char *b = (const char *)fdt;
+	return (pm_t)(b + fdt_totalsize(fdt));
 }
 
 static void setup_pmem(void *fdt)
 {
-	struct mem_layout pmem = get_memlayout(fdt);
+	struct pmem_layout pmem = get_memlayout(fdt);
 
-	pm_t kernel_top = get_kerneltop(fdt);
 	pm_t initrd_top = get_initrdtop(fdt);
+	pm_t kernel_top = get_kerneltop();
 	pm_t fdt_top = get_fdttop(fdt);
 
 	pm_t top = MAX3(kernel_top, initrd_top, fdt_top);
+	dbg("initrd_top:\t%#lx\n", initrd_top);
+	dbg("kernel_top:\t%#lx\n", kernel_top);
+	dbg("fdt_top:\t%#lx\n", fdt_top);
 }
 
-void __noreturn init(void *fdt)
+void init(void *fdt)
 {
 	init_debug(fdt);
 	dbg_fdt(fdt);
 	setup_pmem(fdt);
 
-	/* basic memory layout info */
-	struct mem_layout pmem = get_memlayout(fdt);
-
 	/* TODO: find first contiguous region */
 
 	/* generate pagetable at contiguous region */
-	populate_pmap(pmem.base, pmem.top - pmem.base, 0/* something */);
+	/* populate_pmap(pmem.base, pmem.top - pmem.base, something); */
 
 	/* TODO: mark all used pages */
 	update_pmap(0/* TODO: figure out where in virtual memory the page map should be mapped */);
diff --git a/include/libfdt.h b/include/libfdt.h
index d734715..7425aef 100644
--- a/include/libfdt.h
+++ b/include/libfdt.h
@@ -9,4 +9,7 @@ void __dbg_fdt(void *fdt, int node_offset, int depth);
 #define dbg_fdt(...)
 #endif
 
+#define fdt_load_int_ptr(t, c, p)\
+	((c) == 2 ? (t)fdt64_to_cpu(*(fdt64_t *)(p)) : (t)fdt32_to_cpu(*(fdt32_t *)(p)))
+
 #endif
diff --git a/scripts/gen-deps b/scripts/gen-deps
index 6ddd289..7a468d3 100755
--- a/scripts/gen-deps
+++ b/scripts/gen-deps
@@ -13,7 +13,14 @@ gencommon () {
 }
 genlink () {
 	gencommon ".ld"
-	echo "	\$(GENLINK) $< | \$(STRIPLINK) > \$@"	>> deps.mk
+	if [ "${init}" = "0" ] ; then
+		echo "	\$(GENLINK) $< | \$(STRIPLINK) > \$@"\
+		>> deps.mk;
+	else
+		echo "	\$(GENLINK) $< | \$(STRIPLINK) | \$(KERN_INFO) > \$@"\
+		>> deps.mk;
+	fi
+
 }
 
 genrule () {
@@ -32,10 +39,16 @@ case "${1}" in
 		defs=-DINIT
 		func=genrule
 		;;
-	--link)
+	--init-link)
 		suffix=.ld
+		init=1
 		func=genlink
 		;;
+
+	--kern-link)
+		suffix=.ld
+		init=0
+		func=genlink
 esac
 
 for s in ${2}