[PATCH v3 4/7] Update Elf-ppc to support crash kernel and misc fixes

[Matthew McClintock]

Use current command line if none given, specifically useful for
when arguments are added causing the use of the current cmdline
to not occur

We also try to load the dtb above the kernel, this is useful for
relocatable kernels where they device tree needs to reside just
above the kernel base address

Set the kernel entry address in the relocatable purgatory code
so we jump to the correct start address if not the default. Useful
for relocatable kernels

Signed-off-by: Matthew McClintock <msm at freescale.com>
---
 kexec/arch/ppc/kexec-elf-ppc.c |   26 ++++++++++++++------------
 1 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/kexec/arch/ppc/kexec-elf-ppc.c b/kexec/arch/ppc/kexec-elf-ppc.c
index ab2d343..87e6507 100644
--- a/kexec/arch/ppc/kexec-elf-ppc.c
+++ b/kexec/arch/ppc/kexec-elf-ppc.c
@@ -182,6 +182,7 @@ int elf_ppc_load(int argc, char **argv,	const char *buf, off_t len,
 	int target_is_gamecube = 0;
 	unsigned int addr;
 	unsigned long dtb_addr;
+	unsigned long kernel_addr;
 #endif
 #define FIXUP_ENTRYS	(20)
 	char *fixup_nodes[FIXUP_ENTRYS + 1];
@@ -228,6 +229,9 @@ int elf_ppc_load(int argc, char **argv,	const char *buf, off_t len,
 	command_line_len = 0;
 	if (command_line) {
 		command_line_len = strlen(command_line) + 1;
+	} else {
+		command_line = get_command_line();
+		command_line_len = strlen(command_line) + 1;
 	}
 
 	fixup_nodes[cur_fixup] = NULL;
@@ -264,11 +268,11 @@ int elf_ppc_load(int argc, char **argv,	const char *buf, off_t len,
 	if (size > phdr->p_memsz)
 		size = phdr->p_memsz;
 
-	hole_addr = locate_hole(info, size, 0, 0, max_addr, 1);
+	kernel_addr = locate_hole(info, size, 0, 0, max_addr, 1);
 #ifdef CONFIG_PPC64
-	ehdr.e_phdr[0].p_paddr = (Elf64_Addr)hole_addr;
+	ehdr.e_phdr[0].p_paddr = (Elf64_Addr)kernel_addr;
 #else
-	ehdr.e_phdr[0].p_paddr = hole_addr;
+	ehdr.e_phdr[0].p_paddr = kernel_addr;
 #endif
 
 	/* Load the Elf data */
@@ -343,10 +347,11 @@ int elf_ppc_load(int argc, char **argv,	const char *buf, off_t len,
 		blob_buf = slurp_file(dtb, &blob_size);
 		if (!blob_buf || !blob_size)
 			die("Device tree seems to be an empty file.\n");
+
 		blob_buf = fixup_dtb_nodes(blob_buf, &blob_size, fixup_nodes,
 				cmdline_buf);
-		dtb_addr = add_buffer(info, blob_buf, blob_size, blob_size, 0, 0,
-				KERNEL_ACCESS_TOP, -1);
+		dtb_addr = add_buffer(info, blob_buf, blob_size, blob_size, 0, kernel_addr,
+				kernel_addr + KERNEL_ACCESS_TOP, -1);
 	} else {
 		/* create from fs2dt */
 		seg_buf = NULL;
@@ -364,19 +369,16 @@ int elf_ppc_load(int argc, char **argv,	const char *buf, off_t len,
 
 
 	if (dtb) {
-		/* set various variables for the purgatory */
-		addr = ehdr.e_entry;
+		/* set various variables for the purgatory  ehdr.e_entry is a
+		 * virtual address, we can use kernel_addr which
+		 * should be the physical start address of the kernel */
+		addr = kernel_addr;
 		elf_rel_set_symbol(&info->rhdr, "kernel", &addr, sizeof(addr));
 
 		addr = dtb_addr;
 		elf_rel_set_symbol(&info->rhdr, "dt_offset",
 						&addr, sizeof(addr));
 
-		addr = rmo_top;
-
-		elf_rel_set_symbol(&info->rhdr, "mem_size",
-						&addr, sizeof(addr));
-
 #define PUL_STACK_SIZE	(16 * 1024)
 		addr = locate_hole(info, PUL_STACK_SIZE, 0, 0,
 				elf_max_addr(&ehdr), 1);
-- 
1.6.0.6