Add support for boot arguments specification via fdt

Add suppport for passing boot arguments via FDT for mediatek/ralink SoCs.
This was taken from kan's work on CI20.

Since most OpenWRT dts files have bootargs defined, we use bsdbootargs
to specify FreeBSD specific arguments.

Approved by:	adrian (mentor)
Sponsored by:	Smartcom - Bulgaria AD
Differential Revision:	https://reviews.freebsd.org/D5979

1 files changed, 55 insertions, 0 deletions

diff --git a/sys/mips/mediatek/mtk_machdep.c b/sys/mips/mediatek/mtk_machdep.c
index eeadd4f..aaae780 100644
--- a/sys/mips/mediatek/mtk_machdep.c
+++ b/sys/mips/mediatek/mtk_machdep.c
@@ -192,6 +192,52 @@ mips_init(void)
 #endif
 }
 
+static void
+_parse_bootarg(char *v)
+{
+	char *n;
+
+	if (*v == '-') {
+		while (*v != '\0') {
+			v++;
+			switch (*v) {
+			case 'a': boothowto |= RB_ASKNAME; break;
+			/* Someone should simulate that ;-) */
+			case 'C': boothowto |= RB_CDROM; break;
+			case 'd': boothowto |= RB_KDB; break;
+			case 'D': boothowto |= RB_MULTIPLE; break;
+			case 'm': boothowto |= RB_MUTE; break;
+			case 'g': boothowto |= RB_GDB; break;
+			case 'h': boothowto |= RB_SERIAL; break;
+			case 'p': boothowto |= RB_PAUSE; break;
+			case 'r': boothowto |= RB_DFLTROOT; break;
+			case 's': boothowto |= RB_SINGLE; break;
+			case 'v': boothowto |= RB_VERBOSE; break;
+			}
+		}
+	} else {
+		n = strsep(&v, "=");
+		if (v == NULL)
+			kern_setenv(n, "1");
+		else
+			kern_setenv(n, v);
+	}
+}
+
+/* Parse cmd line args as env - copied from xlp_machdep. */
+/* XXX-BZ this should really be centrally provided for all (boot) code. */
+static void
+_parse_bootargs(char *cmdline)
+{
+	char *v;
+
+	while ((v = strsep(&cmdline, " \n")) != NULL) {
+		if (*v == '\0')
+			continue;
+		_parse_bootarg(v);
+	}
+}
+
 void
 platform_reset(void)
 {
@@ -209,6 +255,8 @@ platform_start(__register_t a0 __unused, __register_t a1 __unused,
 	char **argv = (char **)MIPS_PHYS_TO_KSEG0(a1);
 	char **envp = (char **)MIPS_PHYS_TO_KSEG0(a2);
 	void *dtbp;
+	phandle_t chosen;
+	char buf[2048];
 
 	/* clear the BSS and SBSS segments */
 	kernend = (vm_offset_t)&end;
@@ -238,6 +286,13 @@ platform_start(__register_t a0 __unused, __register_t a1 __unused,
 
 	init_static_kenv(boot1_env, sizeof(boot1_env));
 
+	/*
+	 * Get bsdbootargs from FDT if specified.
+	 */
+	chosen = OF_finddevice("/chosen");
+	if (OF_getprop(chosen, "bsdbootargs", buf, sizeof(buf)) != -1)
+		_parse_bootargs(buf);
+
 	printf("FDT DTB  at: 0x%08x\n", (uint32_t)dtbp);
 
 	printf("CPU   clock: %4dMHz\n", mtk_soc_get_cpuclk()/(1000*1000));