Re: [PATCH -v3 2/2] x86: more early console output from compressed/misc.c

[Yinghai Lu <yinghai@kernel.org>]

On 08/02/2010 02:27 PM, H. Peter Anvin wrote:
> On 08/02/2010 02:08 PM, H. Peter Anvin wrote:
>> On 08/02/2010 01:59 PM, H. Peter Anvin wrote:
>>> On 08/02/2010 12:35 PM, Yinghai Lu wrote:
>>>>
>>>> it seems I can not global variables in arch/x86/boot/compressed/misc.c
>>>>
>>>
>>> I just looked at it, it's the fact that we don't relocate the GOT that
>>> is causing problems.  It's relatively easy to fix: here is a patch, but
>>> in grand Linus tradition it is completely untested.
>>>
>>
>> Untested indeed... here is one which doesn't clobber live registers.
>>
> 
> And of course I got the test backwards... in AT&T syntax, number
> compares you!

updated version

Subject: [PATCH -v4 2/2] x86: more early console output from compressed/misc.c

will get

|Decompressing Linux... Parsing ELF... done.
|Booting the kernel.

in serial console.

reuse code from arch/x86/boot/
and we can use printf if needed

-v2: define BOOT_BOOT_H to avoid include boot.h
-v3: early_serial_base need to be static in misc.c ?
-v4: create seperate string.c printf.c cmdline.c early_serial_console.c
     after hpa's patch that allow global variables in compressed/misc stage

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 arch/x86/boot/compressed/Makefile               |    4 -
 arch/x86/boot/compressed/cmdline.c              |   21 +++++++
 arch/x86/boot/compressed/early_serial_console.c |    4 +
 arch/x86/boot/compressed/misc.c                 |   66 +++++++++++++++---------
 arch/x86/boot/compressed/misc.h                 |   38 +++++++++++++
 arch/x86/boot/compressed/printf.c               |    4 +
 arch/x86/boot/compressed/string.c               |    4 +
 arch/x86/boot/main.c                            |    6 --
 8 files changed, 118 insertions(+), 29 deletions(-)

Index: linux-2.6/arch/x86/boot/compressed/misc.c
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/misc.c
+++ linux-2.6/arch/x86/boot/compressed/misc.c
@@ -9,23 +9,7 @@
  * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
  */
 
-/*
- * we have to be careful, because no indirections are allowed here, and
- * paravirt_ops is a kind of one. As it will only run in baremetal anyway,
- * we just keep it from happening
- */
-#undef CONFIG_PARAVIRT
-#ifdef CONFIG_X86_32
-#define _ASM_X86_DESC_H 1
-#endif
-
-#include <linux/linkage.h>
-#include <linux/screen_info.h>
-#include <linux/elf.h>
-#include <linux/io.h>
-#include <asm/page.h>
-#include <asm/boot.h>
-#include <asm/bootparam.h>
+#include "misc.h"
 
 /* WARNING!!
  * This code is compiled with -fPIC and it is relocated dynamically
@@ -123,15 +107,13 @@ static void error(char *m);
 /*
  * This is set up by the setup-routine at boot-time
  */
-static struct boot_params *real_mode;		/* Pointer to real-mode data */
+struct boot_params *real_mode;		/* Pointer to real-mode data */
 static int quiet;
+static int debug;
 
 void *memset(void *s, int c, size_t n);
 void *memcpy(void *dest, const void *src, size_t n);
 
-static void __putstr(int, const char *);
-#define putstr(__x)  __putstr(0, __x)
-
 #ifdef CONFIG_X86_64
 #define memptr long
 #else
@@ -170,7 +152,21 @@ static void scroll(void)
 		vidmem[i] = ' ';
 }
 
-static void __putstr(int error, const char *s)
+#define XMTRDY          0x20
+
+#define TXR             0       /*  Transmit register (WRITE) */
+#define LSR             5       /*  Line Status               */
+static void serial_putchar(int ch)
+{
+	unsigned timeout = 0xffff;
+
+	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
+		cpu_relax();
+
+	outb(ch, early_serial_base + TXR);
+}
+
+void __putstr(int error, const char *s)
 {
 	int x, y, pos;
 	char c;
@@ -179,6 +175,14 @@ static void __putstr(int error, const ch
 	if (!error)
 		return;
 #endif
+	if (early_serial_base) {
+		const char *str = s;
+		while (*str) {
+			if (*str == '\n')
+				serial_putchar('\r');
+			serial_putchar(*str++);
+		}
+	}
 
 	if (real_mode->screen_info.orig_video_mode == 0 &&
 	    lines == 0 && cols == 0)
@@ -305,8 +309,10 @@ asmlinkage void decompress_kernel(void *
 {
 	real_mode = rmode;
 
-	if (real_mode->hdr.loadflags & QUIET_FLAG)
+	if (cmdline_find_option_bool("quiet"))
 		quiet = 1;
+	if (cmdline_find_option_bool("debug"))
+		debug = 1;
 
 	if (real_mode->screen_info.orig_video_mode == 7) {
 		vidmem = (char *) 0xb0000;
@@ -319,9 +325,23 @@ asmlinkage void decompress_kernel(void *
 	lines = real_mode->screen_info.orig_video_lines;
 	cols = real_mode->screen_info.orig_video_cols;
 
+	console_init();
+	if (debug)
+		putstr("early console in decompress_kernel\n");
+
 	free_mem_ptr     = heap;	/* Heap */
 	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
 
+	if (debug) {
+		putstr("decompress_kernel:\n");
+		printf("  input: [0x%lx-0x%lx], output: 0x%lx, heap: [0x%lx-0x%lx]\n",
+			 (unsigned long)input_data,
+			 (unsigned long)input_data + input_len - 1,
+			 (unsigned long)output,
+			 (unsigned long)heap,
+			 (unsigned long)heap + BOOT_HEAP_SIZE - 1);
+	}
+
 	if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
 		error("Destination address inappropriately aligned");
 #ifdef CONFIG_X86_64
Index: linux-2.6/arch/x86/boot/main.c
===================================================================
--- linux-2.6.orig/arch/x86/boot/main.c
+++ linux-2.6/arch/x86/boot/main.c
@@ -132,6 +132,8 @@ void main(void)
 
 	/* Initialize the early-boot console */
 	console_init();
+	if (cmdline_find_option_bool("debug"))
+		puts("early console in setup code\n");
 
 	/* End of heap check */
 	init_heap();
@@ -171,10 +173,6 @@ void main(void)
 	/* Set the video mode */
 	set_video();
 
-	/* Parse command line for 'quiet' and pass it to decompressor. */
-	if (cmdline_find_option_bool("quiet"))
-		boot_params.hdr.loadflags |= QUIET_FLAG;
-
 	/* Do the last things and invoke protected mode */
 	go_to_protected_mode();
 }
Index: linux-2.6/arch/x86/boot/compressed/Makefile
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/Makefile
+++ linux-2.6/arch/x86/boot/compressed/Makefile
@@ -4,7 +4,7 @@
 # create a compressed vmlinux image from the original vmlinux
 #
 
-targets := vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma vmlinux.bin.lzo head_$(BITS).o misc.o piggy.o
+targets := vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma vmlinux.bin.lzo head_$(BITS).o misc.o string.o printf.o cmdline.o early_serial_console.o piggy.o
 
 KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2
 KBUILD_CFLAGS += -fno-strict-aliasing -fPIC
@@ -23,7 +23,7 @@ LDFLAGS_vmlinux := -T
 
 hostprogs-y	:= mkpiggy
 
-$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o $(obj)/piggy.o FORCE
+$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o $(obj)/string.o $(obj)/printf.o $(obj)/cmdline.o $(obj)/early_serial_console.o $(obj)/piggy.o FORCE
 	$(call if_changed,ld)
 	@:
 
Index: linux-2.6/arch/x86/boot/compressed/cmdline.c
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86/boot/compressed/cmdline.c
@@ -0,0 +1,21 @@
+#include "misc.h"
+
+static unsigned long fs;
+static inline void set_fs(unsigned long seg)
+{
+	fs = seg << 4;  /* shift it back */
+}
+typedef unsigned long addr_t;
+static inline char rdfs8(addr_t addr)
+{
+	return *((char *)(fs + addr));
+}
+#include "../cmdline.c"
+int cmdline_find_option(const char *option, char *buffer, int bufsize)
+{
+	return __cmdline_find_option(real_mode->hdr.cmd_line_ptr, option, buffer, bufsize);
+}
+int cmdline_find_option_bool(const char *option)
+{
+	return __cmdline_find_option_bool(real_mode->hdr.cmd_line_ptr, option);
+}
Index: linux-2.6/arch/x86/boot/compressed/early_serial_console.c
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86/boot/compressed/early_serial_console.c
@@ -0,0 +1,4 @@
+#include "misc.h"
+
+int early_serial_base;
+#include "../early_serial_console.c"
Index: linux-2.6/arch/x86/boot/compressed/misc.h
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86/boot/compressed/misc.h
@@ -0,0 +1,38 @@
+#ifndef BOOT_COMPRESSED_MISC_H
+#define BOOT_COMPRESSED_MISC_H
+
+/*
+ * we have to be careful, because no indirections are allowed here, and
+ * paravirt_ops is a kind of one. As it will only run in baremetal anyway,
+ * we just keep it from happening
+ */
+#undef CONFIG_PARAVIRT
+#ifdef CONFIG_X86_32
+#define _ASM_X86_DESC_H 1
+#endif
+
+#include <linux/linkage.h>
+#include <linux/screen_info.h>
+#include <linux/elf.h>
+#include <linux/io.h>
+#include <asm/page.h>
+#include <asm/boot.h>
+#include <asm/bootparam.h>
+
+#define BOOT_BOOT_H
+
+/* misc.c */
+extern struct boot_params *real_mode;		/* Pointer to real-mode data */
+void __putstr(int error, const char *s);
+#define putstr(__x)  __putstr(0, __x)
+#define puts(__x)  __putstr(0, __x)
+
+/* cmdline.c */
+int cmdline_find_option(const char *option, char *buffer, int bufsize);
+int cmdline_find_option_bool(const char *option);
+
+/* early_serial_console.c */
+extern int early_serial_base;
+void console_init(void);
+
+#endif
Index: linux-2.6/arch/x86/boot/compressed/printf.c
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86/boot/compressed/printf.c
@@ -0,0 +1,4 @@
+#include "misc.h"
+
+#include "../isdigit.h"
+#include "../printf.c"
Index: linux-2.6/arch/x86/boot/compressed/string.c
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86/boot/compressed/string.c
@@ -0,0 +1,4 @@
+#include "misc.h"
+
+#include "../isdigit.h"
+#include "../string.c"