Re: x86 setup code rewrite in C - revised
From: H. Peter Anvin
Date: Wed Jul 11 2007 - 16:30:23 EST
Jeff Garzik wrote:
>
> I'm sure you know what's changed since the last revision, but nobody
> everybody does :) It would be nice to know what's different from the
> last posting.
>
- Added -fno-toplevel-reorder/-fno-unit-at-a-time to the Makefile; this
is necessary for .code16gcc to be safe on all current versions of gcc.
Added comment to that effect to code16gcc.h.
- Moved strnlen, atou and isdigit out of printf.c.
- Corrected title of cpu.c and cpucheck.c.
- Fixed "paragraps" typo in pm.c.
- Removed bogus <linux/edd.h> in string.c.
- Removed #include <linux/mmzone.h> from asm-x86/e820.h; according to
Andi it isn't needed even for non-_SETUP, and my compile testing seems
to confirm that.
Full diff attached.
-hpa
diff --git a/arch/i386/boot/Makefile b/arch/i386/boot/Makefile
index e9f46fd..08678a0 100644
--- a/arch/i386/boot/Makefile
+++ b/arch/i386/boot/Makefile
@@ -57,6 +57,8 @@ CFLAGS := $(LINUXINCLUDE) -g -Os -D_SETUP -D__KERNEL__ \
-include $(srctree)/$(src)/code16gcc.h \
-fno-strict-aliasing -fomit-frame-pointer \
$(call cc-option, -ffreestanding) \
+ $(call cc-option, -fno-toplevel-reorder,\
+ $(call cc-option, -fno-unit-at-a-time)) \
$(call cc-option, -fno-stack-protector) \
$(call cc-option, -mpreferred-stack-boundary=2)
AFLAGS := $(CFLAGS) -D__ASSEMBLY__
diff --git a/arch/i386/boot/boot.h b/arch/i386/boot/boot.h
index 7251ef6..0329c4f 100644
--- a/arch/i386/boot/boot.h
+++ b/arch/i386/boot/boot.h
@@ -192,6 +192,11 @@ static inline int memcmp_gs(const void *s1, addr_t s2, size_t len)
return diff;
}
+static inline int isdigit(int ch)
+{
+ return (ch >= '0') && (ch <= '9');
+}
+
/* Heap -- available for dynamic lists. */
#define STACK_SIZE 512 /* Minimum number of bytes for stack */
@@ -261,13 +266,14 @@ void __attribute__((noreturn))
protected_mode_jump(u32 entrypoint, u32 bootparams);
/* printf.c */
-unsigned int atou(const char *s);
int sprintf(char *buf, const char *fmt, ...);
int vsprintf(char *buf, const char *fmt, va_list args);
int printf(const char *fmt, ...);
/* string.c */
int strcmp(const char *str1, const char *str2);
+size_t strnlen(const char *s, size_t maxlen);
+unsigned int atou(const char *s);
/* tty.c */
void puts(const char *);
diff --git a/arch/i386/boot/code16gcc.h b/arch/i386/boot/code16gcc.h
index dbc6414..3bd8480 100644
--- a/arch/i386/boot/code16gcc.h
+++ b/arch/i386/boot/code16gcc.h
@@ -2,6 +2,12 @@
* code16gcc.h
*
* This file is -include'd when compiling 16-bit C code.
+ * Note: this asm() needs to be emitted before gcc omits any code.
+ * Depending on gcc version, this requires -fno-unit-at-a-time or
+ * -fno-toplevel-reorder.
+ *
+ * Hopefully gcc will eventually have a real -m16 option so we can
+ * drop this hack long term.
*/
#ifndef __ASSEMBLY__
diff --git a/arch/i386/boot/cpu.c b/arch/i386/boot/cpu.c
index 042d894..2a5c32d 100644
--- a/arch/i386/boot/cpu.c
+++ b/arch/i386/boot/cpu.c
@@ -9,7 +9,7 @@
* ----------------------------------------------------------------------- */
/*
- * arch/i386/boot/cpucheck.c
+ * arch/i386/boot/cpu.c
*
* Check for obligatory CPU features and abort if the features are not
* present.
diff --git a/arch/i386/boot/cpucheck.c b/arch/i386/boot/cpucheck.c
index 431bef8..8b0f447 100644
--- a/arch/i386/boot/cpucheck.c
+++ b/arch/i386/boot/cpucheck.c
@@ -9,7 +9,7 @@
* ----------------------------------------------------------------------- */
/*
- * arch/i386/boot/cpu.c
+ * arch/i386/boot/cpucheck.c
*
* Check for obligatory CPU features and abort if the features are not
* present. This code should be compilable as 16-, 32- or 64-bit
diff --git a/arch/i386/boot/pm.c b/arch/i386/boot/pm.c
index 4deb298..3fa53e1 100644
--- a/arch/i386/boot/pm.c
+++ b/arch/i386/boot/pm.c
@@ -49,7 +49,7 @@ static void move_kernel_around(void)
dst_seg = 0x1000 >> 4;
src_seg = 0x10000 >> 4;
- syssize = boot_params.hdr.syssize; /* Size in 16-byte paragraps */
+ syssize = boot_params.hdr.syssize; /* Size in 16-byte paragraphs */
while (syssize) {
int paras = (syssize >= 0x1000) ? 0x1000 : syssize;
diff --git a/arch/i386/boot/printf.c b/arch/i386/boot/printf.c
index ee3d9fc..1a09f93 100644
--- a/arch/i386/boot/printf.c
+++ b/arch/i386/boot/printf.c
@@ -19,11 +19,6 @@
#include "boot.h"
-static inline int isdigit(int ch)
-{
- return (ch >= '0') && (ch <= '9');
-}
-
static int skip_atoi(const char **s)
{
int i = 0;
@@ -33,25 +28,6 @@ static int skip_atoi(const char **s)
return i;
}
-unsigned int atou(const char *s)
-{
- unsigned int i = 0;
- while (isdigit(*s))
- i = i * 10 + (*s++ - '0');
- return i;
-}
-
-static int strnlen(const char *s, int maxlen)
-{
- const char *es = s;
- while (*es && maxlen) {
- es++;
- maxlen--;
- }
-
- return (es - s);
-}
-
#define ZEROPAD 1 /* pad with zero */
#define SIGN 2 /* unsigned/signed long */
#define PLUS 4 /* show plus */
diff --git a/arch/i386/boot/string.c b/arch/i386/boot/string.c
index 0808197..481a220 100644
--- a/arch/i386/boot/string.c
+++ b/arch/i386/boot/string.c
@@ -15,7 +15,6 @@
*/
#include "boot.h"
-#include <linux/edd.h>
int strcmp(const char *str1, const char *str2)
{
@@ -32,3 +31,22 @@ int strcmp(const char *str1, const char *str2)
}
return 0;
}
+
+size_t strnlen(const char *s, size_t maxlen)
+{
+ const char *es = s;
+ while (*es && maxlen) {
+ es++;
+ maxlen--;
+ }
+
+ return (es - s);
+}
+
+unsigned int atou(const char *s)
+{
+ unsigned int i = 0;
+ while (isdigit(*s))
+ i = i * 10 + (*s++ - '0');
+ return i;
+}
diff --git a/include/asm-x86_64/e820.h b/include/asm-x86_64/e820.h
index 15eb8e2..3486e70 100644
--- a/include/asm-x86_64/e820.h
+++ b/include/asm-x86_64/e820.h
@@ -11,10 +11,6 @@
#ifndef __E820_HEADER
#define __E820_HEADER
-#ifndef _SETUP
-# include <linux/mmzone.h>
-#endif
-
#define E820MAP 0x2d0 /* our map */
#define E820MAX 128 /* number of entries in E820MAP */
#define E820NR 0x1e8 /* # entries in E820MAP */