1 files changed, 497 insertions, 0 deletions

diff --git a/src/boot/selfboot.c b/src/boot/selfboot.c
new file mode 100644
index 0000000000..6aae0d8f55
--- /dev/null
+++ b/src/boot/selfboot.c
@@ -0,0 +1,497 @@
+#include <console/console.h>
+#include <part/fallback_boot.h>
+#include <boot/elf.h>
+#include <boot/elf_boot.h>
+#include <boot/coreboot_tables.h>
+#include <ip_checksum.h>
+#include <stream/read_bytes.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <romfs.h>
+
+#ifndef CONFIG_BIG_ENDIAN
+#define ntohl(x) ( ((x&0xff)<<24) | ((x&0xff00)<<8) | \
+		((x&0xff0000) >> 8) | ((x&0xff000000) >> 24) )
+#else
+#define ntohl(x) (x)
+#endif
+
+/* Maximum physical address we can use for the coreboot bounce buffer.
+ */
+#ifndef MAX_ADDR
+#define MAX_ADDR -1UL
+#endif
+
+extern unsigned char _ram_seg;
+extern unsigned char _eram_seg;
+
+struct segment {
+	struct segment *next;
+	struct segment *prev;
+	struct segment *phdr_next;
+	struct segment *phdr_prev;
+	unsigned long s_dstaddr;
+	unsigned long s_srcaddr;
+	unsigned long s_memsz;
+	unsigned long s_filesz;
+};
+
+struct verify_callback {
+	struct verify_callback *next;
+	int (*callback)(struct verify_callback *vcb, 
+		Elf_ehdr *ehdr, Elf_phdr *phdr, struct segment *head);
+	unsigned long desc_offset;
+	unsigned long desc_addr;
+};
+
+struct ip_checksum_vcb {
+	struct verify_callback data;
+	unsigned short ip_checksum;
+};
+
+int romfs_self_decompress(int algo, void *src,struct segment *new)
+{
+	u8 *dst;
+
+	/* for uncompressed, it's easy: just point at the area in ROM */
+	if (algo ==  ROMFS_COMPRESS_NONE) {
+		new->s_srcaddr = (u32) src;
+		new->s_filesz =  new->s_memsz;
+		return 0;
+	}
+
+	/* for compression, let's keep it simple. We'll malloc the destination 
+	 * area and decompress to there. The compression overhead far outweighs
+	 * any overhead for an extra copy. 
+	 */
+	dst = malloc(new->s_memsz);
+	if (! dst)
+		return -1;
+
+	switch(algo) {
+#ifdef CONFIG_COMPRESSION_LZMA
+	case ROMFS_COMPRESS_LZMA: {
+		unsigned long ulzma(unsigned char *src, unsigned char *dst);		
+		ulzma(src, dst);
+	}
+#endif
+
+#ifdef CONFIG_COMPRESSION_NRV2B
+	case ROMFS_COMPRESS_NRV2B: {
+		unsigned long unrv2b(u8 *src, u8 *dst, unsigned long *ilen_p);
+		unsigned long tmp;
+		unrv2b(src, dst, &tmp);
+	}
+#endif
+	default:
+		printk_info( "ROMFS:  Unknown compression type %d\n",
+		       algo);
+		return -1;
+	}
+
+	new->s_srcaddr = (u32) dst;
+	new->s_filesz =  new->s_memsz;
+	return 0;
+	
+}
+
+/* The problem:  
+ * Static executables all want to share the same addresses
+ * in memory because only a few addresses are reliably present on
+ * a machine, and implementing general relocation is hard.
+ *
+ * The solution:
+ * - Allocate a buffer twice the size of the coreboot image.
+ * - Anything that would overwrite coreboot copy into the lower half of
+ *   the buffer. 
+ * - After loading an ELF image copy coreboot to the upper half of the
+ *   buffer.
+ * - Then jump to the loaded image.
+ * 
+ * Benefits:
+ * - Nearly arbitrary standalone executables can be loaded.
+ * - Coreboot is preserved, so it can be returned to.
+ * - The implementation is still relatively simple,
+ *   and much simpler then the general case implemented in kexec.
+ * 
+ */
+
+static unsigned long get_bounce_buffer(struct lb_memory *mem)
+{
+	unsigned long lb_size;
+	unsigned long mem_entries;
+	unsigned long buffer;
+	int i;
+	lb_size = (unsigned long)(&_eram_seg - &_ram_seg);
+	/* Double coreboot size so I have somewhere to place a copy to return to */
+	lb_size = lb_size + lb_size;
+	mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
+	buffer = 0;
+	for(i = 0; i < mem_entries; i++) {
+		unsigned long mstart, mend;
+		unsigned long msize;
+		unsigned long tbuffer;
+		if (mem->map[i].type != LB_MEM_RAM)
+			continue;
+		if (unpack_lb64(mem->map[i].start) > MAX_ADDR)
+			continue;
+		if (unpack_lb64(mem->map[i].size) < lb_size)
+			continue;
+		mstart = unpack_lb64(mem->map[i].start);
+		msize = MAX_ADDR - mstart +1;
+		if (msize > unpack_lb64(mem->map[i].size))
+			msize = unpack_lb64(mem->map[i].size);
+		mend = mstart + msize;
+		tbuffer = mend - lb_size;
+		if (tbuffer < buffer) 
+			continue;
+		buffer = tbuffer;
+	}
+	return buffer;
+}
+
+static int valid_area(struct lb_memory *mem, unsigned long buffer,
+	unsigned long start, unsigned long len)
+{
+	/* Check through all of the memory segments and ensure
+	 * the segment that was passed in is completely contained
+	 * in RAM.
+	 */
+	int i;
+	unsigned long end = start + len;
+	unsigned long mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
+
+	/* See if I conflict with the bounce buffer */
+	if (end >= buffer) {
+		return 0;
+	}
+
+	/* Walk through the table of valid memory ranges and see if I
+	 * have a match.
+	 */
+	for(i = 0; i < mem_entries; i++) {
+		uint64_t mstart, mend;
+		uint32_t mtype;
+		mtype = mem->map[i].type;
+		mstart = unpack_lb64(mem->map[i].start);
+		mend = mstart + unpack_lb64(mem->map[i].size);
+		if ((mtype == LB_MEM_RAM) && (start < mend) && (end > mstart)) {
+			break;
+		}
+		if ((mtype == LB_MEM_TABLE) && (start < mend) && (end > mstart)) {
+			printk_err("Payload is overwriting Coreboot tables.\n");
+			break;
+		}
+	}
+	if (i == mem_entries) {
+		printk_err("No matching ram area found for range:\n");
+		printk_err("  [0x%016lx, 0x%016lx)\n", start, end);
+		printk_err("Ram areas\n");
+		for(i = 0; i < mem_entries; i++) {
+			uint64_t mstart, mend;
+			uint32_t mtype;
+			mtype = mem->map[i].type;
+			mstart = unpack_lb64(mem->map[i].start);
+			mend = mstart + unpack_lb64(mem->map[i].size);
+			printk_err("  [0x%016lx, 0x%016lx) %s\n",
+				(unsigned long)mstart, 
+				(unsigned long)mend, 
+				(mtype == LB_MEM_RAM)?"RAM":"Reserved");
+			
+		}
+		return 0;
+	}
+	return 1;
+}
+
+static void relocate_segment(unsigned long buffer, struct segment *seg)
+{
+	/* Modify all segments that want to load onto coreboot
+	 * to load onto the bounce buffer instead.
+	 */
+	unsigned long lb_start = (unsigned long)&_ram_seg;
+	unsigned long lb_end = (unsigned long)&_eram_seg;
+	unsigned long start, middle, end;
+
+	printk_spew("lb: [0x%016lx, 0x%016lx)\n", 
+		lb_start, lb_end);
+
+	start = seg->s_dstaddr;
+	middle = start + seg->s_filesz;
+	end = start + seg->s_memsz;
+	/* I don't conflict with coreboot so get out of here */
+	if ((end <= lb_start) || (start >= lb_end))
+		return;
+
+	printk_spew("segment: [0x%016lx, 0x%016lx, 0x%016lx)\n", 
+		start, middle, end);
+
+	/* Slice off a piece at the beginning
+	 * that doesn't conflict with coreboot.
+	 */
+	if (start < lb_start) {
+		struct segment *new;
+		unsigned long len = lb_start - start;
+		new = malloc(sizeof(*new));
+		*new = *seg;
+		new->s_memsz = len;
+		seg->s_memsz -= len;
+		seg->s_dstaddr += len;
+		seg->s_srcaddr += len;
+		if (seg->s_filesz > len) {
+			new->s_filesz = len;
+			seg->s_filesz -= len;
+		} else {
+			seg->s_filesz = 0;
+		}
+
+		/* Order by stream offset */
+		new->next = seg;
+		new->prev = seg->prev;
+		seg->prev->next = new;
+		seg->prev = new;
+		/* Order by original program header order */
+		new->phdr_next = seg;
+		new->phdr_prev = seg->phdr_prev;
+		seg->phdr_prev->phdr_next = new;
+		seg->phdr_prev = new;
+
+		/* compute the new value of start */
+		start = seg->s_dstaddr;
+		
+		printk_spew("   early: [0x%016lx, 0x%016lx, 0x%016lx)\n", 
+			new->s_dstaddr, 
+			new->s_dstaddr + new->s_filesz,
+			new->s_dstaddr + new->s_memsz);
+	}
+	
+	/* Slice off a piece at the end 
+	 * that doesn't conflict with coreboot 
+	 */
+	if (end > lb_end) {
+		unsigned long len = lb_end - start;
+		struct segment *new;
+		new = malloc(sizeof(*new));
+		*new = *seg;
+		seg->s_memsz = len;
+		new->s_memsz -= len;
+		new->s_dstaddr += len;
+		new->s_srcaddr += len;
+		if (seg->s_filesz > len) {
+			seg->s_filesz = len;
+			new->s_filesz -= len;
+		} else {
+			new->s_filesz = 0;
+		}
+		/* Order by stream offset */
+		new->next = seg->next;
+		new->prev = seg;
+		seg->next->prev = new;
+		seg->next = new;
+		/* Order by original program header order */
+		new->phdr_next = seg->phdr_next;
+		new->phdr_prev = seg;
+		seg->phdr_next->phdr_prev = new;
+		seg->phdr_next = new;
+
+		/* compute the new value of end */
+		end = start + len;
+		
+		printk_spew("   late: [0x%016lx, 0x%016lx, 0x%016lx)\n", 
+			new->s_dstaddr, 
+			new->s_dstaddr + new->s_filesz,
+			new->s_dstaddr + new->s_memsz);
+		
+	}
+	/* Now retarget this segment onto the bounce buffer */
+	/* sort of explanation: the buffer is a 1:1 mapping to coreboot. 
+	 * so you will make the dstaddr be this buffer, and it will get copied
+	 * later to where coreboot lives.
+	 */
+	seg->s_dstaddr = buffer + (seg->s_dstaddr - lb_start);
+
+	printk_spew(" bounce: [0x%016lx, 0x%016lx, 0x%016lx)\n", 
+		seg->s_dstaddr, 
+		seg->s_dstaddr + seg->s_filesz, 
+		seg->s_dstaddr + seg->s_memsz);
+}
+
+
+static int build_self_segment_list(
+	struct segment *head, 
+	unsigned long bounce_buffer, struct lb_memory *mem,
+	struct romfs_payload *payload, u32 *entry)
+{
+	struct segment *new;
+	struct segment *ptr;
+	u8 *data;
+	int datasize;
+	struct romfs_payload_segment *segment, *first_segment;
+	memset(head, 0, sizeof(*head));
+	head->phdr_next = head->phdr_prev = head;
+	head->next = head->prev = head;
+	first_segment = segment = &payload->segments;
+
+	while(1) {
+		printk_debug("Segment %p\n", segment);
+		switch(segment->type) {
+		default: printk_emerg("Bad segment type %x\n", segment->type);
+			return -1;
+		case PAYLOAD_SEGMENT_PARAMS:
+			printk_info("found param section\n");
+			segment++;
+			continue;
+		case PAYLOAD_SEGMENT_CODE:
+		case PAYLOAD_SEGMENT_DATA:
+			printk_info( "%s: ", segment->type == PAYLOAD_SEGMENT_CODE ? 
+				"code" : "data");
+		new = malloc(sizeof(*new));
+		new->s_dstaddr = ntohl((u32) segment->load_addr);
+		new->s_memsz = ntohl(segment->mem_len);
+
+		datasize = ntohl(segment->len);
+		/* figure out decompression, do it, get pointer to the area */
+		if (romfs_self_decompress(ntohl(segment->compression),
+					     ((unsigned char *) first_segment) +
+					     ntohl(segment->offset), new)) {
+			printk_emerg("romfs_self_decompress failed\n");
+			return;
+		}
+		printk_debug("New segment dstaddr 0x%lx memsize 0x%lx srcaddr 0x%lx filesize 0x%lx\n",
+			new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
+		/* Clean up the values */
+		if (new->s_filesz > new->s_memsz)  {
+			new->s_filesz = new->s_memsz;
+		}
+		printk_debug("(cleaned up) New segment addr 0x%lx size 0x%lx offset 0x%lx filesize 0x%lx\n",
+			new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
+		break;
+		case PAYLOAD_SEGMENT_BSS:
+			printk_info("BSS %p/%d\n", (void *) ntohl((u32) segment->load_addr),
+				 ntohl(segment->mem_len));
+			new = malloc(sizeof(*new));
+			new->s_filesz = 0;
+			new->s_dstaddr = ntohl((u32) segment->load_addr);
+			new->s_memsz = ntohl(segment->mem_len);
+
+			break;
+
+		case PAYLOAD_SEGMENT_ENTRY:
+			printk_info("Entry %p\n", (void *) ntohl((u32) segment->load_addr));
+			*entry =  (void *) ntohl((u32) segment->load_addr);
+			return 1;
+		}
+		segment++;
+		for(ptr = head->next; ptr != head; ptr = ptr->next) {
+			if (new->s_srcaddr < ntohl((u32) segment->load_addr))
+				break;
+		}
+		/* Order by stream offset */
+		new->next = ptr;
+		new->prev = ptr->prev;
+		ptr->prev->next = new;
+		ptr->prev = new;
+		/* Order by original program header order */
+		new->phdr_next = head;
+		new->phdr_prev = head->phdr_prev;
+		head->phdr_prev->phdr_next  = new;
+		head->phdr_prev = new;
+
+		/* Verify the memory addresses in the segment are valid */
+		if (!valid_area(mem, bounce_buffer, new->s_dstaddr, new->s_memsz)) 
+			goto out;
+
+		/* Modify the segment to load onto the bounce_buffer if necessary.
+		 */
+		relocate_segment(bounce_buffer, new);
+	}
+	return 1;
+ out:
+	return 0;
+}
+
+static int load_self_segments(
+	struct segment *head, struct romfs_payload *payload)
+{
+	unsigned long offset;
+	struct segment *ptr;
+	
+	offset = 0;
+	for(ptr = head->next; ptr != head; ptr = ptr->next) {
+		unsigned long skip_bytes, read_bytes;
+		unsigned char *dest, *middle, *end, *src;
+		byte_offset_t result;
+		printk_debug("Loading Segment: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
+			ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
+		
+		/* Compute the boundaries of the segment */
+		dest = (unsigned char *)(ptr->s_dstaddr);
+		end = dest + ptr->s_memsz;
+		middle = dest + ptr->s_filesz;
+		src = ptr->s_srcaddr;
+		printk_spew("[ 0x%016lx, %016lx, 0x%016lx) <- %016lx\n",
+			(unsigned long)dest,
+			(unsigned long)middle,
+			(unsigned long)end,
+			(unsigned long)src);
+		
+		/* Copy data from the initial buffer */
+		if (ptr->s_filesz) {
+			size_t len;
+			len = ptr->s_filesz;
+			memcpy(dest, src, len);
+			dest += len;
+		}
+		
+		/* Zero the extra bytes between middle & end */
+		if (middle < end) {
+			printk_debug("Clearing Segment: addr: 0x%016lx memsz: 0x%016lx\n",
+				(unsigned long)middle, (unsigned long)(end - middle));
+			
+			/* Zero the extra bytes */
+			memset(middle, 0, end - middle);
+		}
+	}
+	return 1;
+ out:
+	return 0;
+}
+
+int selfboot(struct lb_memory *mem, struct romfs_payload *payload)
+{
+	void *entry;
+	struct segment head;
+	unsigned long bounce_buffer;
+
+	/* Find a bounce buffer so I can load to coreboot's current location */
+	bounce_buffer = get_bounce_buffer(mem);
+	if (!bounce_buffer) {
+		printk_err("Could not find a bounce buffer...\n");
+		goto out;
+	}
+
+	/* Preprocess the self segments */
+	if (!build_self_segment_list(&head, bounce_buffer, mem, payload, &entry))
+		goto out;
+
+	/* Load the segments */
+	if (!load_self_segments(&head, payload))
+		goto out;
+
+	printk_spew("Loaded segments\n");
+
+	/* Reset to booting from this image as late as possible */
+	boot_successful();
+
+	printk_debug("Jumping to boot code at %p\n", entry);
+	post_code(0xfe);
+
+	/* Jump to kernel */
+	jmp_to_elf_entry(entry, bounce_buffer);
+	return 1;
+
+ out:
+	return 0;
+}
+