x86: Fix support for booting bzImage

Add support for newer (up to 2.6.33) kernels

Add zboot command which takes the address of a bzImage as its first
argument and (optionally) the size of the bzImage as the second argument
(the second argument is needed for older kernels which do not include
the bzImage size in the header)

Signed-off-by: Graeme Russ <graeme.russ@gmail.com>

1 files changed, 95 insertions, 32 deletions

diff --git a/arch/i386/lib/zimage.c b/arch/i386/lib/zimage.c
index c3b4e59..b39615a 100644
--- a/arch/i386/lib/zimage.c
+++ b/arch/i386/lib/zimage.c
@@ -34,6 +34,8 @@
 #include <asm/zimage.h>
 #include <asm/realmode.h>
 #include <asm/byteorder.h>
+#include <asm/bootparam.h>
+#include <asm/ic/sc520.h>
 
 /*
  * Memory lay-out:
@@ -90,48 +92,56 @@ void *load_zimage(char *image, unsigned long kernel_size,
 	int big_image;
 	void *load_address;
 
+	struct setup_header *hdr = (struct setup_header *)(image + SETUP_SECTS_OFF);
 
 	setup_base = (void*)DEFAULT_SETUP_BASE;	/* base address for real-mode segment */
 
-	if (KERNEL_MAGIC != *(u16*)(image + BOOT_FLAG_OFF)) {
-		printf("Error: Invalid kernel magic (found 0x%04x, expected 0xaa55)\n",
-		       *(u16*)(image + BOOT_FLAG_OFF));
+	if (KERNEL_MAGIC != hdr->boot_flag) {
+		printf("Error: Invalid Boot Flag (found 0x%04x, expected 0x%04x)\n",
+				hdr->boot_flag, KERNEL_MAGIC);
 		return 0;
+	} else {
+		printf("Valid Boot Flag\n");
 	}
 
-
 	/* determine boot protocol version */
-	if (KERNEL_V2_MAGIC == *(u32*)(image+HEADER_OFF)) {
-		bootproto = *(u16*)(image+VERSION_OFF);
+	if (KERNEL_V2_MAGIC == hdr->header) {
+		printf("Magic signature found\n");
+
+		bootproto = hdr->version;
 	} else {
 		/* Very old kernel */
+		printf("Magic signature not found\n");
 		bootproto = 0x0100;
 	}
 
 	/* determine size of setup */
-	if (0 == *(u8*)(image + SETUP_SECTS_OFF)) {
+	if (0 == hdr->setup_sects) {
+		printf("Setup Sectors = 0 (defaulting to 4)\n");
 		setup_size = 5 * 512;
 	} else {
-		setup_size = (*(u8*)(image + SETUP_SECTS_OFF) + 1) * 512;
+		setup_size = (hdr->setup_sects + 1) * 512;
 	}
 
+	printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
+
 	if (setup_size > SETUP_MAX_SIZE) {
 		printf("Error: Setup is too large (%d bytes)\n", setup_size);
 	}
 
 	/* Determine image type */
-	big_image = (bootproto >= 0x0200) && (*(u8*)(image + LOADFLAGS_OFF) & BIG_KERNEL_FLAG);
+	big_image = (bootproto >= 0x0200) && (hdr->loadflags & BIG_KERNEL_FLAG);
 
-	/* Derermine load address */
-	load_address = (void*)(big_image ? BZIMAGE_LOAD_ADDR:ZIMAGE_LOAD_ADDR);
+	/* Determine load address */
+	load_address = (void*)(big_image ? BZIMAGE_LOAD_ADDR : ZIMAGE_LOAD_ADDR);
 
 	/* load setup */
+	printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", (ulong)setup_base, setup_size);
 	memmove(setup_base, image, setup_size);
 
 	printf("Using boot protocol version %x.%02x\n",
 	       (bootproto & 0xff00) >> 8, bootproto & 0xff);
 
-
 	if (bootproto == 0x0100) {
 
 		*(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
@@ -154,48 +164,58 @@ void *load_zimage(char *image, unsigned long kernel_size,
 		memset((void*)0x90000 + setup_size, 0, SETUP_MAX_SIZE-setup_size);
 	}
 
+	/* We are now setting up the real-mode version of the header */
+	hdr = (struct setup_header *)(setup_base + SETUP_SECTS_OFF);
+
 	if (bootproto >= 0x0200) {
-		*(u8*)(setup_base + TYPE_OF_LOADER_OFF) = 0xff;
-		printf("Linux kernel version %s\n",
-		       (char*)(setup_base + SETUP_START_OFFSET +
-			       *(u16*)(setup_base + START_SYS_OFF + 2)));
+		hdr->type_of_loader = 8;
+
+		if (hdr->setup_sects >= 15)
+			printf("Linux kernel version %s\n", (char *)
+					(setup_base + (hdr->kernel_version + 0x200)));
+		else
+			printf("Setup Sectors < 15 - Cannot print kernel version.\n");
 
 		if (initrd_addr) {
 			printf("Initial RAM disk at linear address 0x%08lx, size %ld bytes\n",
 			       initrd_addr, initrd_size);
 
-			*(u32*)(setup_base + RAMDISK_IMAGE_OFF) = initrd_addr;
-			*(u32*)(setup_base + RAMDISK_SIZE_OFF)=initrd_size;
+			hdr->ramdisk_image = initrd_addr;
+			hdr->ramdisk_size = initrd_size;
 		}
 	}
 
 	if (bootproto >= 0x0201) {
-		*(u16*)(setup_base + HEAP_END_PTR_OFF) = HEAP_END_OFFSET;
-
-		/* CAN_USE_HEAP */
-		*(u8*)(setup_base + LOADFLAGS_OFF) =
-			*(u8*)(setup_base + LOADFLAGS_OFF) | HEAP_FLAG;
+		hdr->heap_end_ptr = HEAP_END_OFFSET;
+		hdr->loadflags |= HEAP_FLAG;
 	}
 
 	if (bootproto >= 0x0202) {
-		*(u32*)(setup_base + CMD_LINE_PTR_OFF) = (u32)setup_base + COMMAND_LINE_OFFSET;
+		hdr->cmd_line_ptr = (u32)setup_base + COMMAND_LINE_OFFSET;
 	} else if (bootproto >= 0x0200) {
+
 		*(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
 		*(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;
-		*(u16*)(setup_base + SETUP_MOVE_SIZE_OFF) = 0x9100;
+
+		hdr->setup_move_size = 0x9100;
 	}
 
+	if (bootproto >= 0x0204)
+		kernel_size = hdr->syssize * 16;
+	else
+		kernel_size -= setup_size;
+
 
 	if (big_image) {
-		if ((kernel_size - setup_size) > BZIMAGE_MAX_SIZE) {
+		if ((kernel_size) > BZIMAGE_MAX_SIZE) {
 			printf("Error: bzImage kernel too big! (size: %ld, max: %d)\n",
-			       kernel_size - setup_size, BZIMAGE_MAX_SIZE);
+			       kernel_size, BZIMAGE_MAX_SIZE);
 			return 0;
 		}
 
-	} else if ((kernel_size - setup_size) > ZIMAGE_MAX_SIZE) {
+	} else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
 		printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
-		       kernel_size - setup_size, ZIMAGE_MAX_SIZE);
+		       kernel_size, ZIMAGE_MAX_SIZE);
 		return 0;
 	}
 
@@ -203,10 +223,10 @@ void *load_zimage(char *image, unsigned long kernel_size,
 	build_command_line(setup_base + COMMAND_LINE_OFFSET, auto_boot);
 
 	printf("Loading %czImage at address 0x%08x (%ld bytes)\n", big_image ? 'b' : ' ',
-	       (u32)load_address, kernel_size - setup_size);
+	       (u32)load_address, kernel_size);
 
 
-	memmove(load_address, image + setup_size, kernel_size - setup_size);
+	memmove(load_address, image + setup_size, kernel_size);
 
 	/* ready for booting */
 	return setup_base;
@@ -218,8 +238,51 @@ void boot_zimage(void *setup_base)
 
 	memset(&regs, 0, sizeof(struct pt_regs));
 	regs.xds = (u32)setup_base >> 4;
-	regs.xss = 0x9000;
+	regs.xes = regs.xds;
+	regs.xss = regs.xds;
 	regs.esp = 0x9000;
 	regs.eflags = 0;
 	enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, &regs, &regs);
 }
+
+int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+	void *base_ptr;
+	void *bzImage_addr;
+	ulong bzImage_size = 0;
+
+	disable_interrupts();
+
+	/* Setup board for maximum PC/AT Compatibility */
+	setup_pcat_compatibility();
+
+	/* argv[1] holds the address of the bzImage */
+	bzImage_addr = (void *)simple_strtoul(argv[1], NULL, 16);
+
+	if (argc == 3)
+		bzImage_size = simple_strtoul(argv[2], NULL, 16);
+
+	/* Lets look for*/
+	base_ptr = load_zimage (bzImage_addr, bzImage_size, 0, 0, 0);
+
+	if (NULL == base_ptr) {
+		printf ("## Kernel loading failed ...\n");
+	} else {
+		printf ("## Transferring control to Linux (at address %08x) ...\n",
+			(u32)base_ptr);
+
+		/* we assume that the kernel is in place */
+		printf("\nStarting kernel ...\n\n");
+
+		boot_zimage(base_ptr);
+		/* does not return */
+	}
+
+	return -1;
+}
+
+U_BOOT_CMD(
+	zboot, 3, 0,	do_zboot,
+	"Boot bzImage",
+	""
+);