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[GDB] Atomic read/write for device memory

This commit is contained in:
Stefan Hajnoczi 2008-06-05 20:07:23 +01:00 committed by Michael Brown
parent 59b5465b30
commit 9ec3ff95f0
1 changed files with 53 additions and 13 deletions
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66
src/core/gdbstub.c
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@ -27,7 +27,7 @@
#include <stddef.h>
#include <stdio.h>
#include <ctype.h>
#include <assert.h>
#include <byteswap.h>
#include <gpxe/process.h>
#include <gpxe/serial.h>
#include "gdbmach.h"
@ -67,20 +67,60 @@ static uint8_t gdbstub_to_hex_digit ( uint8_t b ) {
return ( b < 0xa ? '0' : 'a' - 0xa ) + b;
}
static void gdbstub_from_hex_buf ( char *dst, char *src, int len ) {
while ( len-- > 0 ) {
*dst = gdbstub_from_hex_digit ( *src++ );
if ( len-- > 0 ) {
*dst = (*dst << 4) | gdbstub_from_hex_digit ( *src++ );
/*
* To make reading/writing device memory atomic, we check for
* 2- or 4-byte aligned operations and handle them specially.
*/
static void gdbstub_from_hex_buf ( char *dst, char *src, int lenbytes ) {
if ( lenbytes == 2 && ( ( unsigned long ) dst & 0x1 ) == 0 ) {
uint16_t i = gdbstub_from_hex_digit ( src [ 2 ] ) << 12 |
gdbstub_from_hex_digit ( src [ 3 ] ) << 8 |
gdbstub_from_hex_digit ( src [ 0 ] ) << 4 |
gdbstub_from_hex_digit ( src [ 1 ] );
* ( uint16_t * ) dst = cpu_to_le16 ( i );
} else if ( lenbytes == 4 && ( ( unsigned long ) dst & 0x3 ) == 0 ) {
uint32_t i = gdbstub_from_hex_digit ( src [ 6 ] ) << 28 |
gdbstub_from_hex_digit ( src [ 7 ] ) << 24 |
gdbstub_from_hex_digit ( src [ 4 ] ) << 20 |
gdbstub_from_hex_digit ( src [ 5 ] ) << 16 |
gdbstub_from_hex_digit ( src [ 2 ] ) << 12 |
gdbstub_from_hex_digit ( src [ 3 ] ) << 8 |
gdbstub_from_hex_digit ( src [ 0 ] ) << 4 |
gdbstub_from_hex_digit ( src [ 1 ] );
* ( uint32_t * ) dst = cpu_to_le32 ( i );
} else {
while ( lenbytes-- > 0 ) {
*dst++ = gdbstub_from_hex_digit ( src [ 0 ] ) << 4 |
gdbstub_from_hex_digit ( src [ 1 ] );
src += 2;
}
dst++;
}
}
static void gdbstub_to_hex_buf ( char *dst, char *src, int len ) {
while ( len-- > 0 ) {
*dst++ = gdbstub_to_hex_digit ( *src >> 4 );
*dst++ = gdbstub_to_hex_digit ( *src++ );
static void gdbstub_to_hex_buf ( char *dst, char *src, int lenbytes ) {
if ( lenbytes == 2 && ( ( unsigned long ) src & 0x1 ) == 0 ) {
uint16_t i = cpu_to_le16 ( * ( uint16_t * ) src );
dst [ 0 ] = gdbstub_to_hex_digit ( i >> 4 );
dst [ 1 ] = gdbstub_to_hex_digit ( i );
dst [ 2 ] = gdbstub_to_hex_digit ( i >> 12 );
dst [ 3 ] = gdbstub_to_hex_digit ( i >> 8 );
} else if ( lenbytes == 4 && ( ( unsigned long ) src & 0x3 ) == 0 ) {
uint32_t i = cpu_to_le32 ( * ( uint32_t * ) src );
dst [ 0 ] = gdbstub_to_hex_digit ( i >> 4 );
dst [ 1 ] = gdbstub_to_hex_digit ( i );
dst [ 2 ] = gdbstub_to_hex_digit ( i >> 12 );
dst [ 3 ] = gdbstub_to_hex_digit ( i >> 8 );
dst [ 4 ] = gdbstub_to_hex_digit ( i >> 20 );
dst [ 5 ] = gdbstub_to_hex_digit ( i >> 16);
dst [ 6 ] = gdbstub_to_hex_digit ( i >> 28 );
dst [ 7 ] = gdbstub_to_hex_digit ( i >> 24 );
} else {
while ( lenbytes-- > 0 ) {
*dst++ = gdbstub_to_hex_digit ( *src >> 4 );
*dst++ = gdbstub_to_hex_digit ( *src );
src++;
}
}
}
@ -179,7 +219,7 @@ static void gdbstub_write_regs ( struct gdbstub *stub ) {
gdbstub_send_errno ( stub, POSIX_EINVAL );
return;
}
gdbstub_from_hex_buf ( ( char * ) stub->regs, &stub->payload [ 1 ], stub->len );
gdbstub_from_hex_buf ( ( char * ) stub->regs, &stub->payload [ 1 ], GDBMACH_SIZEOF_REGS );
gdbstub_send_ok ( stub );
}
@ -204,7 +244,7 @@ static void gdbstub_write_mem ( struct gdbstub *stub ) {
gdbstub_send_errno ( stub, POSIX_EINVAL );
return;
}
gdbstub_from_hex_buf ( ( char * ) args [ 0 ], &stub->payload [ colon + 1 ], stub->len - colon - 1 );
gdbstub_from_hex_buf ( ( char * ) args [ 0 ], &stub->payload [ colon + 1 ], ( stub->len - colon - 1 ) / 2 );
gdbstub_send_ok ( stub );
}