MIPS: TXx9: Add prom_getenv

Add prom_getenv() which can be used for YAMON.  This assumes other
firmware should pass NULL for fw_arg2.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 16 insertions, 0 deletions

diff --git a/arch/mips/txx9/generic/setup.c b/arch/mips/txx9/generic/setup.c
index 33d8c9e3223d..005179c2af21 100644
--- a/arch/mips/txx9/generic/setup.c
+++ b/arch/mips/txx9/generic/setup.c
@@ -212,6 +212,21 @@ char * __init prom_getcmdline(void)
         return &(arcs_cmdline[0]);
 }
 
+const char *__init prom_getenv(const char *name)
+{
+        const s32 *str = (const s32 *)fw_arg2;
+
+        if (!str)
+                return NULL;
+        /* YAMON style ("name", "value" pairs) */
+        while (str[0] && str[1]) {
+                if (!strcmp((const char *)(unsigned long)str[0], name))
+                        return (const char *)(unsigned long)str[1];
+                str += 2;
+        }
+        return NULL;
+}
+
 static void __noreturn txx9_machine_halt(void)
 {
         local_irq_disable();
diff --git a/include/asm-mips/txx9/generic.h b/include/asm-mips/txx9/generic.h
index c9eed7ea148c..0a225bf73496 100644
--- a/include/asm-mips/txx9/generic.h
+++ b/include/asm-mips/txx9/generic.h
@@ -43,6 +43,7 @@ struct txx9_board_vec {
 extern struct txx9_board_vec *txx9_board_vec;
 extern int (*txx9_irq_dispatch)(int pending);
 char *prom_getcmdline(void);
+const char *prom_getenv(const char *name);
 void txx9_wdt_init(unsigned long base);
 void txx9_spi_init(int busid, unsigned long base, int irq);
 void txx9_ethaddr_init(unsigned int id, unsigned char *ethaddr);