Determine kernel load address dynamically from u-boot memory map.

The generic ELF loading code maps the kernel into low memory
by subtracting KERN_BASE.  So the copyin/copyout/readin functions
are always called with low addresses.  This code finds the largest
DRAM block from the U-Boot memory map and adds that base to
the addresses.

In particular, this fixes ubldr on AM3358, which has DRAM
mapped to 0x80000000 at power-on.

3 files changed, 46 insertions, 10 deletions

diff --git a/sys/boot/uboot/lib/copy.c b/sys/boot/uboot/lib/copy.c
index e5e4626..71b7a94 100644
--- a/sys/boot/uboot/lib/copy.c
+++ b/sys/boot/uboot/lib/copy.c
@@ -29,32 +29,64 @@
 __FBSDID("$FreeBSD$");
 
 #include <stand.h>
+#include <stdint.h>
+
+#include "api_public.h"
+#include "glue.h"
 
 /*
  * MD primitives supporting placement of module data 
- *
- * XXX should check load address/size against memory top.
  */
 
+void *
+uboot_vm_translate(vm_offset_t o) {
+	struct sys_info *si;
+	static uintptr_t start = 0;
+	static size_t size = 0;
+	int i;
+
+	if (size == 0) {
+		if ((si = ub_get_sys_info()) == NULL)
+			panic("could not retrieve system info");
+
+		/* Find start/size of largest DRAM block. */
+		for (i = 0; i < si->mr_no; i++) {
+			if (si->mr[i].flags == MR_ATTR_DRAM
+			    && si->mr[i].size > size) {
+				start = si->mr[i].start;
+				size = si->mr[i].size;
+			}
+		}
+
+		if (size <= 0)
+			panic("No suitable DRAM?\n");
+		/*
+		printf("Loading into memory region 0x%08X-0x%08X (%d MiB)\n",
+		    start, start + size, size / 1024 / 1024);
+		*/
+	}
+	if (o > size)
+		panic("Address 0x%08jX bigger than size 0x%08X\n",
+		      (intmax_t)o, size);
+	return (void *)(start + o);
+}
+
 ssize_t
 uboot_copyin(const void *src, vm_offset_t dest, const size_t len)
 {
-
-	bcopy(src, (void *)dest, len);
+	bcopy(src, uboot_vm_translate(dest), len);
 	return (len);
 }
 
 ssize_t
 uboot_copyout(const vm_offset_t src, void *dest, const size_t len)
 {
-
-	bcopy((void *)src, dest, len);
+	bcopy(uboot_vm_translate(src), dest, len);
 	return (len);
 }
 
 ssize_t
 uboot_readin(const int fd, vm_offset_t dest, const size_t len)
 {
-
-	return (read(fd, (void *) dest, len));
+	return (read(fd, uboot_vm_translate(dest), len));
 }
diff --git a/sys/boot/uboot/lib/elf_freebsd.c b/sys/boot/uboot/lib/elf_freebsd.c
index 222c314..bbde80c 100644
--- a/sys/boot/uboot/lib/elf_freebsd.c
+++ b/sys/boot/uboot/lib/elf_freebsd.c
@@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$");
 #include <stand.h>
 
 #include "bootstrap.h"
+#include "libuboot.h"
 
 extern vm_offset_t md_load(char *, vm_offset_t *);
 
@@ -69,6 +70,7 @@ __elfN(uboot_exec)(struct preloaded_file *fp)
 	vm_offset_t mdp;
 	Elf_Ehdr *e;
 	int error;
+	void (*entry)(void *);
 
 	if ((fmp = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL)
 		return (EFTYPE);
@@ -78,11 +80,12 @@ __elfN(uboot_exec)(struct preloaded_file *fp)
 	if ((error = md_load(fp->f_args, &mdp)) != 0)
 		return (error);
 
-	printf("Kernel entry at 0x%x ...\n", e->e_entry);
+	entry = uboot_vm_translate(e->e_entry);
+	printf("Kernel entry at 0x%x...\n", (unsigned)entry);
 
 	dev_cleanup();
 
-	(*(void (*)())e->e_entry)((void *)mdp);
+	(*entry)((void *)mdp);
 	panic("exec returned");
 }
 
diff --git a/sys/boot/uboot/lib/libuboot.h b/sys/boot/uboot/lib/libuboot.h
index e0ddb1a..16f4331 100644
--- a/sys/boot/uboot/lib/libuboot.h
+++ b/sys/boot/uboot/lib/libuboot.h
@@ -60,6 +60,7 @@ extern int devs_no;
 extern struct netif_driver uboot_net;
 extern struct devsw uboot_storage;
 
+void *uboot_vm_translate(vm_offset_t);
 ssize_t	uboot_copyin(const void *src, vm_offset_t dest, const size_t len);
 ssize_t	uboot_copyout(const vm_offset_t src, void *dest, const size_t len);
 ssize_t	uboot_readin(const int fd, vm_offset_t dest, const size_t len);