We often need to retrieve hexadecimal kernel parameters.
Let's implement a shared utility to do it.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
lib/s390x/kernel-args.c | 60 +++++++++++++++++++++++++++++++++++++++++
lib/s390x/kernel-args.h | 18 +++++++++++++
s390x/Makefile | 1 +
3 files changed, 79 insertions(+)
create mode 100644 lib/s390x/kernel-args.c
create mode 100644 lib/s390x/kernel-args.h
diff --git a/lib/s390x/kernel-args.c b/lib/s390x/kernel-args.c
new file mode 100644
index 0000000..3335fbf
--- /dev/null
+++ b/lib/s390x/kernel-args.c
@@ -0,0 +1,60 @@
+/*
+ * Retrieving kernel arguments
+ *
+ * Copyright (c) 2020 IBM Corp
+ *
+ * Authors:
+ * Pierre Morel <pmorel@xxxxxxxxxxxxx>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#include <libcflat.h>
+#include <string.h>
+#include <asm/arch_def.h>
+#include <kernel-args.h>
+
+static const char *hex_digit = "0123456789abcdef";
+
+static unsigned long htol(char *s)
+{
+ unsigned long v = 0, shift = 0, value = 0;
+ int i, digit, len = strlen(s);
+
+ for (shift = 0, i = len - 1; i >= 0; i--, shift += 4) {
+ digit = s[i] | 0x20; /* Set lowercase */
+ if (!strchr(hex_digit, digit))
+ return 0; /* this is not a digit ! */
+
+ if (digit <= '9')
+ v = digit - '0';
+ else
+ v = digit - 'a' + 10;
+ value += (v << shift);
+ }
+
+ return value;
+}
+
+int kernel_arg(int argc, char *argv[], const char *str, unsigned long *val)
+{
+ int i, ret;
+ char *p;
+
+ for (i = 0; i < argc; i++) {
+ ret = strncmp(argv[i], str, strlen(str));
+ if (ret)
+ continue;
+ p = strchr(argv[i], '=');
+ if (!p)
+ return -1;
+ p = strchr(p, 'x');
+ if (!p)
+ *val = atol(p + 1);
+ else
+ *val = htol(p + 1);
+ return 0;
+ }
+ return -2;
+}
diff --git a/lib/s390x/kernel-args.h b/lib/s390x/kernel-args.h
new file mode 100644
index 0000000..a88e34e
--- /dev/null
+++ b/lib/s390x/kernel-args.h
@@ -0,0 +1,18 @@
+/*
+ * Kernel argument
+ *
+ * Copyright (c) 2020 IBM Corp
+ *
+ * Authors:
+ * Pierre Morel <pmorel@xxxxxxxxxxxxx>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef KERNEL_ARGS_H
+#define KERNEL_ARGS_H
+
+int kernel_arg(int argc, char *argv[], const char *str, unsigned long *val);
+
+#endif
diff --git a/s390x/Makefile b/s390x/Makefile
index ddb4b48..47a94cc 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -51,6 +51,7 @@ cflatobjs += lib/s390x/sclp-console.o
cflatobjs += lib/s390x/interrupt.o
cflatobjs += lib/s390x/mmu.o
cflatobjs += lib/s390x/smp.o
+cflatobjs += lib/s390x/kernel-args.o
OBJDIRS += lib/s390x
--
2.25.1
