ar71xx: Add kernel 4.9 support

This add support for kernel 4.9 to the ar71xx target.
It was compile tested with the generic, NAND and mikrotik subtarget.
Multiple members of the community tested it on their boards and did not
report any major problem so far.

Especially the NAND part received some changes to adapt to the new
kernel APIs. The serial driver hack used for the Arduino Yun was not
ported because the kernel changed there a lot.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

1 files changed, 73 insertions, 0 deletions

diff --git a/target/linux/ar71xx/patches-4.9/508-MIPS-ath79-prom-image-command-line-hack.patch b/target/linux/ar71xx/patches-4.9/508-MIPS-ath79-prom-image-command-line-hack.patch
new file mode 100644
index 0000000000..cfa5e72eec
--- /dev/null
+++ b/target/linux/ar71xx/patches-4.9/508-MIPS-ath79-prom-image-command-line-hack.patch
@@ -0,0 +1,73 @@
+--- a/arch/mips/ath79/prom.c
++++ b/arch/mips/ath79/prom.c
+@@ -33,6 +33,41 @@ static void __init ath79_prom_append_cmd
+ 	strlcat(arcs_cmdline, ath79_cmdline_buf, sizeof(arcs_cmdline));
+ }
+ 
++#ifdef CONFIG_IMAGE_CMDLINE_HACK
++extern char __image_cmdline[];
++
++static int __init ath79_use_image_cmdline(void)
++{
++	char *p = __image_cmdline;
++	int replace = 0;
++
++	if (*p == '-') {
++		replace = 1;
++		p++;
++	}
++
++	if (*p == '\0')
++		return 0;
++
++	if (replace) {
++		strlcpy(arcs_cmdline, p, sizeof(arcs_cmdline));
++	} else {
++		strlcat(arcs_cmdline, " ", sizeof(arcs_cmdline));
++		strlcat(arcs_cmdline, p, sizeof(arcs_cmdline));
++	}
++
++	/* Validate and setup environment pointer */
++	if (fw_arg2 < CKSEG0)
++		_fw_envp = NULL;
++	else
++		_fw_envp = (int *)fw_arg2;
++
++	return 1;
++}
++#else
++static inline int ath79_use_image_cmdline(void) { return 0; }
++#endif
++
+ static int __init ath79_prom_init_myloader(void)
+ {
+ 	struct myloader_info *mylo;
+@@ -61,6 +96,8 @@ static int __init ath79_prom_init_myload
+ 
+ 	ath79_prom_append_cmdline("ethaddr", mac_buf);
+ 
++	ath79_use_image_cmdline();
++
+ 	return 1;
+ }
+ 
+@@ -71,7 +108,8 @@ void __init prom_init(void)
+ 	if (ath79_prom_init_myloader())
+ 		return;
+ 
+-	fw_init_cmdline();
++	if (!ath79_use_image_cmdline())
++		fw_init_cmdline();
+ 
+ 	env = fw_getenv("ethaddr");
+ 	if (env)
+--- a/arch/mips/fw/lib/cmdline.c
++++ b/arch/mips/fw/lib/cmdline.c
+@@ -35,6 +35,7 @@ void __init fw_init_cmdline(void)
+ 	else
+ 		_fw_envp = (int *)fw_arg2;
+ 
++	arcs_cmdline[0] = '\0';
+ 	for (i = 1; i < fw_argc; i++) {
+ 		strlcat(arcs_cmdline, fw_argv(i), COMMAND_LINE_SIZE);
+ 		if (i < (fw_argc - 1))