microblaze: Cleanup compiled-in rootfs in BSS section

This patch is based on patch from Steve Magnani.

There were bug for compiled-in rootfs. We have to move
moving rootfs which is in BSS section to _ebss section
which is at the end of kernel and then clear bss section
not vice-versa.

Signed-off-by: Michal Simek <monstr@monstr.eu>

1 files changed, 32 insertions, 21 deletions

diff --git a/arch/microblaze/kernel/setup.c b/arch/microblaze/kernel/setup.c
index c156b16f9ee9..8709bea09604 100644
--- a/arch/microblaze/kernel/setup.c
+++ b/arch/microblaze/kernel/setup.c
@@ -98,6 +98,29 @@ void __init machine_early_init(const char *cmdline, unsigned int ram,
 {
         unsigned long *src, *dst = (unsigned long *)0x0;
 
+        /* If CONFIG_MTD_UCLINUX is defined, assume ROMFS is at the
+         * end of kernel. There are two position which we want to check.
+         * The first is __init_end and the second __bss_start.
+         */
+#ifdef CONFIG_MTD_UCLINUX
+        int romfs_size;
+        unsigned int romfs_base;
+        char *old_klimit = klimit;
+
+        romfs_base = (ram ? ram : (unsigned int)&__init_end);
+        romfs_size = PAGE_ALIGN(get_romfs_len((unsigned *)romfs_base));
+        if (!romfs_size) {
+                romfs_base = (unsigned int)&__bss_start;
+                romfs_size = PAGE_ALIGN(get_romfs_len((unsigned *)romfs_base));
+        }
+
+        /* Move ROMFS out of BSS before clearing it */
+        if (romfs_size > 0) {
+                memmove(&_ebss, (int *)romfs_base, romfs_size);
+                klimit += romfs_size;
+        }
+#endif
+
 /* clearing bss section */
         memset(__bss_start, 0, __bss_stop-__bss_start);
         memset(_ssbss, 0, _esbss-_ssbss);
@@ -119,27 +142,15 @@ void __init machine_early_init(const char *cmdline, unsigned int ram,
         printk(KERN_NOTICE "Found FDT at 0x%08x\n", fdt);
 
 #ifdef CONFIG_MTD_UCLINUX
-        {
-                int size;
-                unsigned int romfs_base;
-                romfs_base = (ram ? ram : (unsigned int)&__init_end);
-                /* if CONFIG_MTD_UCLINUX_EBSS is defined, assume ROMFS is at the
-                 * end of kernel, which is ROMFS_LOCATION defined above. */
-                size = PAGE_ALIGN(get_romfs_len((unsigned *)romfs_base));
-                early_printk("Found romfs @ 0x%08x (0x%08x)\n",
-                                romfs_base, size);
-                early_printk("#### klimit %p ####\n", klimit);
-                BUG_ON(size < 0); /* What else can we do? */
-
-                /* Use memmove to handle likely case of memory overlap */
-                early_printk("Moving 0x%08x bytes from 0x%08x to 0x%08x\n",
-                        size, romfs_base, (unsigned)&_ebss);
-                memmove(&_ebss, (int *)romfs_base, size);
-
-                /* update klimit */
-                klimit += PAGE_ALIGN(size);
-                early_printk("New klimit: 0x%08x\n", (unsigned)klimit);
-        }
+        early_printk("Found romfs @ 0x%08x (0x%08x)\n",
+                        romfs_base, romfs_size);
+        early_printk("#### klimit %p ####\n", old_klimit);
+        BUG_ON(romfs_size < 0); /* What else can we do? */
+
+        early_printk("Moved 0x%08x bytes from 0x%08x to 0x%08x\n",
+                        romfs_size, romfs_base, (unsigned)&_ebss);
+
+        early_printk("New klimit: 0x%08x\n", (unsigned)klimit);
 #endif
 
         for (src = __ivt_start; src < __ivt_end; src++, dst++)