Ron? Marc? Can anyone check this on real hardware?
The printk buffer is located in Geode LX memory:
- while CAR is enabled: starting at 0x80000 (CONFIG_CARBASE) size 16k
(CONFIG_CARSIZE / 2)
- after CAR is disabled: starting at 0x90000 size 64k
On 11.02.2008 16:19, Carl-Daniel Hailfinger wrote:
> On 11.02.2008 04:19, Peter Stuge wrote:
>
>> On Mon, Feb 11, 2008 at 03:01:39AM +0100, Carl-Daniel Hailfinger wrote:
>>
>>
>>> New version, without the recently merged stuff.
>>>
>>> If you want to dump the buffer from the Qemu monitor after CAR has been
>>> disabled, use this command:
>>> memsave 0x90000 65536 memdump.bin
>>>
>>>
>> How do we fuse it with the kernel message buffer?
>>
>
> That problem still needs to be solved.
>
Still to be done, but not really the scope of the patch.
>>> Tested on Qemu, should work on LX. Code needs to get in mergeable
>>> shape before commit, but I'd appreciate testers on LX with FS2.
>>>
>>> Signed-off-by: Carl-Daniel Hailfinger <[EMAIL PROTECTED]>
>>>
>>>
>> Acked-by: Peter Stuge <[EMAIL PROTECTED]>
>>
>> But please wait for comments from others too. I also have no way of
>> testing this.
>>
>
> You could test on Qemu. I'll write up a really short Howto.
>
Run qemu with "-monitor stdio", then press "C-a c" on the console and
issue this command:
memsave 0x90000 65536 memdump.bin
memdump.bin now contains the printk message buffer (inlcuding header).
>>> Index: LinuxBIOSv3-printkbuffer/arch/x86/geodelx/stage0.S
>>> ===================================================================
>>> --- LinuxBIOSv3-printkbuffer/arch/x86/geodelx/stage0.S (Revision 587)
>>> +++ LinuxBIOSv3-printkbuffer/arch/x86/geodelx/stage0.S (Arbeitskopie)
>>> @@ -361,6 +361,11 @@
>>> movw %ax, %ss
>>>
>>> lout:
>>> + /* Store pointer to start of printk buffer, should really use
>>> + * PRINTK_BUF_ADDR_CAR instead.
>>> + */
>>> + movl $CONFIG_CARBASE, %eax
>>>
>>>
>> So why not do that?
>>
>
> We'd have to import PRINTK_BUF_ADDR_CAR from some header. We need to
> create such a platform-specific header which exists on all platforms.
> Maybe cpu.h?
>
To be solved. Not necessary for merge.
>>> + /* -4-4 because CONFIG_CARBASE + CONFIG_CARSIZE - 4 is initial %esp */
>>> + return (void *)(CONFIG_CARBASE + CONFIG_CARSIZE - 4 - 4);
>>> +}
>>>
>>>
>> Is it really bottom of stack and not top? esp decreases, and the
>> pointer is pushed before anything else?
>>
>> Oh! It could be the bottom of the stack even though it has the
>> highest memory address. That's a bit confusing though.
>>
>
> Yes, I'll add a better comment later.
>
Still to be done.
Regards,
Carl-Daniel
New patch with printk buffer as default-on Kconfig variable. Stack
checking removed, can be introduced in a separate patch. Lots of cleanup
and correctness fixes.
Tested on Qemu, should work on Geode as well.
Signed-off-by: Carl-Daniel Hailfinger <[EMAIL PROTECTED]>
Index: LinuxBIOSv3-printkbuffer/include/console.h
===================================================================
--- LinuxBIOSv3-printkbuffer/include/console.h (Revision 587)
+++ LinuxBIOSv3-printkbuffer/include/console.h (Arbeitskopie)
@@ -37,6 +37,10 @@
unsigned char console_rx_byte(void);
int console_tst_byte(void);
void die(const char *msg);
+#ifdef CONFIG_CONSOLE_BUFFER
+void printk_buffer_init(void);
+void printk_buffer_move(void *newaddr, int newsize);
+#endif
struct console_driver {
void (*init)(void);
@@ -46,6 +50,15 @@
int (*tst_byte)(void);
};
+#ifdef CONFIG_CONSOLE_BUFFER
+struct printk_buffer {
+ int len;
+ int readoffset;
+ int writeoffset;
+ char buffer[];
+};
+#endif
+
SHARED_WITH_ATTRIBUTES(printk, int, __attribute__((format (printf, 2, 3))),
int msg_level, const char *fmt, ...);
SHARED(banner, void, int msg_level, const char *msg);
Index: LinuxBIOSv3-printkbuffer/include/arch/x86/cpu.h
===================================================================
--- LinuxBIOSv3-printkbuffer/include/arch/x86/cpu.h (Revision 587)
+++ LinuxBIOSv3-printkbuffer/include/arch/x86/cpu.h (Arbeitskopie)
@@ -24,6 +24,7 @@
#include <types.h>
#include <device/device.h>
+#include <shared.h>
#define X86_VENDOR_INTEL 0
#define X86_VENDOR_CYRIX 1
@@ -196,4 +197,13 @@
__asm__ __volatile__("hlt" : : : "memory");
}
+SHARED(bottom_of_stack, void *, void);
+
+#ifdef CONFIG_CONSOLE_BUFFER
+#define PRINTK_BUF_SIZE_CAR (CONFIG_CARSIZE / 2)
+#define PRINTK_BUF_ADDR_CAR CONFIG_CARBASE
+#define PRINTK_BUF_SIZE_RAM 65536
+#define PRINTK_BUF_ADDR_RAM 0x90000
+#endif
+
#endif /* ARCH_X86_CPU_H */
Index: LinuxBIOSv3-printkbuffer/lib/Kconfig
===================================================================
--- LinuxBIOSv3-printkbuffer/lib/Kconfig (Revision 587)
+++ LinuxBIOSv3-printkbuffer/lib/Kconfig (Arbeitskopie)
@@ -223,5 +223,12 @@
When you enable this option, coreboot will prefix each line of
console output with '(LB)'.
+config CONSOLE_BUFFER
+ boolean "Console memory buffer support"
+ default y
+ depends CONSOLE
+ help
+ Save coreboot output in a memory buffer.
+
endmenu
Index: LinuxBIOSv3-printkbuffer/lib/console.c
===================================================================
--- LinuxBIOSv3-printkbuffer/lib/console.c (Revision 587)
+++ LinuxBIOSv3-printkbuffer/lib/console.c (Arbeitskopie)
@@ -3,6 +3,7 @@
#include <console.h>
#include <uart8250.h>
#include <stdarg.h>
+#include <string.h>
int vtxprintf(void (*)(unsigned char, void *arg),
void *arg, const char *, va_list);
@@ -12,8 +13,80 @@
return CONFIG_DEFAULT_CONSOLE_LOGLEVEL;
}
+#ifdef CONFIG_CONSOLE_BUFFER
+void printk_buffer_move(void *newaddr, int newsize)
+{
+ struct printk_buffer **p;
+ struct printk_buffer *oldbuf, *newbuf;
+ int copylen;
+ p = bottom_of_stack();
+ oldbuf = *p;
+ newbuf = newaddr;
+ newbuf->len = newsize;
+ newbuf->readoffset = 0;
+ /* Check for wraparound */
+ if (oldbuf->writeoffset < oldbuf->readoffset) {
+ /* Copy from readoffset to end of buffer. */
+ copylen = oldbuf->len - oldbuf->readoffset;
+ } else {
+ /* Copy from readoffset to writeoffset (exclusive).*/
+ copylen = oldbuf->writeoffset - oldbuf->readoffset;
+ }
+ if (copylen > newsize)
+ copylen = newsize;
+ /* If memcpy() ever uses printk we will see pretty explosions. */
+ memcpy(&newbuf->buffer[0], &oldbuf->buffer[oldbuf->readoffset],
+ copylen);
+ newbuf->writeoffset = copylen;
+ /* Check for wraparound */
+ if (oldbuf->writeoffset < oldbuf->readoffset) {
+ /* Copy from start of buffer to writeoffset (exclusive). */
+ copylen = (copylen + oldbuf->writeoffset > newsize)
+ ? newsize - copylen : oldbuf->writeoffset;
+ memcpy(&newbuf->buffer[newbuf->writeoffset],
+ &oldbuf->buffer[0], copylen);
+ newbuf->writeoffset += copylen;
+ }
+ *p = newbuf;
+ return;
+}
+
+struct printk_buffer *printk_buffer_addr(void)
+{
+ struct printk_buffer **p;
+ p = bottom_of_stack();
+ return *p;
+}
+
+void printk_buffer_init(void)
+{
+ struct printk_buffer *buf = printk_buffer_addr();
+ buf->len = PRINTK_BUF_SIZE_CAR - sizeof(struct printk_buffer);
+ buf->readoffset = 0;
+ buf->writeoffset = 0;
+ return;
+}
+
+void buffer_tx_byte(unsigned char byte, void *arg)
+{
+ struct printk_buffer *buf = printk_buffer_addr();
+ buf->buffer[buf->writeoffset++] = byte;
+ buf->writeoffset %= buf->len;
+ /* Make sure writeoffset is always ahead of readoffset here. */
+ if (buf->writeoffset == buf->readoffset) {
+ buf->readoffset++;
+ buf->readoffset %= buf->len;
+ }
+ return;
+}
+#endif
+
void console_tx_byte(unsigned char byte, void *arg)
{
+#ifdef CONFIG_CONSOLE_BUFFER
+ buffer_tx_byte(byte, arg);
+#endif
+#ifdef CONFIG_CONSOLE_SERIAL
if (byte == '\n') {
uart8250_tx_byte(TTYSx_BASE, '\r');
#if defined(CONFIG_CONSOLE_PREFIX) && (CONFIG_CONSOLE_PREFIX == 1)
@@ -26,8 +99,8 @@
return;
#endif
}
-
uart8250_tx_byte(TTYSx_BASE, byte);
+#endif
}
int printk(int msg_level, const char *fmt, ...)
Index: LinuxBIOSv3-printkbuffer/arch/x86/geodelx/stage0.S
===================================================================
--- LinuxBIOSv3-printkbuffer/arch/x86/geodelx/stage0.S (Revision 587)
+++ LinuxBIOSv3-printkbuffer/arch/x86/geodelx/stage0.S (Arbeitskopie)
@@ -361,6 +361,13 @@
movw %ax, %ss
lout:
+#ifdef CONFIG_CONSOLE_BUFFER
+ /* Store pointer to start of printk buffer, should really use
+ * PRINTK_BUF_ADDR_CAR instead.
+ */
+ movl $CONFIG_CARBASE, %eax
+ pushl %eax /* printk buffer */
+#endif
/* Restore the BIST result. */
movl %ebp, %eax
Index: LinuxBIOSv3-printkbuffer/arch/x86/stage0_i586.S
===================================================================
--- LinuxBIOSv3-printkbuffer/arch/x86/stage0_i586.S (Revision 587)
+++ LinuxBIOSv3-printkbuffer/arch/x86/stage0_i586.S (Arbeitskopie)
@@ -433,7 +433,13 @@
movw %ax, %ss
lout:
-
+#ifdef CONFIG_CONSOLE_BUFFER
+ /* Store pointer to start of printk buffer, should really use
+ * PRINTK_BUF_ADDR_CAR instead.
+ */
+ movl $CONFIG_CARBASE, %eax
+ pushl %eax /* printk buffer */
+#endif
/* Restore the BIST result */
movl %ebp, %eax
/* We need to set ebp ? No need */
Index: LinuxBIOSv3-printkbuffer/arch/x86/stage1.c
===================================================================
--- LinuxBIOSv3-printkbuffer/arch/x86/stage1.c (Revision 587)
+++ LinuxBIOSv3-printkbuffer/arch/x86/stage1.c (Arbeitskopie)
@@ -26,6 +26,7 @@
#include <tables.h>
#include <lib.h>
#include <mc146818rtc.h>
+#include <cpu.h>
/* ah, well, what a mess! This is a hard code. FIX ME but how?
* By getting rid of ELF ...
@@ -67,6 +68,12 @@
}
+void *bottom_of_stack(void)
+{
+ /* -4-4 because CONFIG_CARBASE + CONFIG_CARSIZE - 4 is initial %esp */
+ return (void *)(CONFIG_CARBASE + CONFIG_CARSIZE - 4 - 4);
+}
+
void dump_mem_range(int msg_level, unsigned char *buf, int size)
{
int i;
@@ -129,6 +136,11 @@
// We have cache as ram running and can start executing code in C.
+#ifdef CONFIG_CONSOLE_BUFFER
+ /* Initialize the printk buffer. */
+ printk_buffer_init();
+#endif
+
hardware_stage1();
//
@@ -173,10 +185,14 @@
printk(BIOS_DEBUG, "Done RAM init code\n");
-
/* Turn off Cache-As-Ram */
disable_car();
+#ifdef CONFIG_CONSOLE_BUFFER
+ /* Move the printk buffer to PRINTK_BUF_ADDR_RAM */
+ printk_buffer_move((void *)PRINTK_BUF_ADDR_RAM, PRINTK_BUF_SIZE_RAM);
+#endif
+
entry = load_file_segments(&archive, "normal/stage2");
if (entry == (void *)-1)
die("FATAL: Failed loading stage2.");
--
http://www.hailfinger.org/
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