[PATCH]: 2.6.8.1, additional options for embedded systems

From: Dmitry Golubev
Date: Tue Aug 31 2004 - 15:14:36 EST

Additionally to the patch I sent earlier today, this patch:
- adds option to disable IGMP (that's rarely needed for desktops)
- adds option to disable DOUBLEFAULT for x86 systems

Please apply both - saves about 20K compresses or 50K uncompressed, which is
very good for embedded systems.

Dmitry
diff -Naur -X ./patt ./linux-2.6.8.1/arch/i386/kernel/Makefile ./linux-2.6.8.1_new/arch/i386/kernel/Makefile
--- ./linux-2.6.8.1/arch/i386/kernel/Makefile 2004-08-14 13:54:51.000000000 +0300
+++ ./linux-2.6.8.1_new/arch/i386/kernel/Makefile 2004-08-31 20:35:51.000000000 +0300
@@ -6,9 +6,9 @@

obj-y := process.o semaphore.o signal.o entry.o traps.o irq.o vm86.o \
ptrace.o i8259.o ioport.o ldt.o setup.o time.o sys_i386.o \
- pci-dma.o i386_ksyms.o i387.o dmi_scan.o bootflag.o \
- doublefault.o
+ pci-dma.o i386_ksyms.o i387.o dmi_scan.o bootflag.o

+obj-$(CONFIG_DOUBLEFAULT) += doublefault.o
obj-y += cpu/
obj-y += timers/
obj-$(CONFIG_ACPI_BOOT) += acpi/
diff -Naur -X ./patt ./linux-2.6.8.1/arch/i386/kernel/cpu/common.c ./linux-2.6.8.1_new/arch/i386/kernel/cpu/common.c
--- ./linux-2.6.8.1/arch/i386/kernel/cpu/common.c 2004-08-14 13:54:48.000000000 +0300
+++ ./linux-2.6.8.1_new/arch/i386/kernel/cpu/common.c 2004-08-31 20:39:06.000000000 +0300
@@ -228,8 +228,9 @@
if (cap0 & (1<<19))
c->x86_cache_alignment = ((misc >> 8) & 0xff) * 8;
}
-
+#ifdef CONFIG_X86_CPU_VENDOR_INTEL
early_intel_workaround(c);
+#endif
}

void __init generic_identify(struct cpuinfo_x86 * c)
@@ -460,28 +461,84 @@
* Then, when cpu_init() is called, we can just iterate over that array.
*/

+#ifdef CONFIG_X86_CPU_VENDOR_INTEL
+
extern int intel_cpu_init(void);
+
+#endif
+
+#ifdef CONFIG_X86_CPU_VENDOR_CYRIX
+
extern int cyrix_init_cpu(void);
extern int nsc_init_cpu(void);
+
+#endif
+
+#ifdef CONFIG_X86_CPU_VENDOR_AMD
+
extern int amd_init_cpu(void);
+
+#endif
+
+#ifdef CONFIG_X86_CPU_VENDOR_CENTAUR
+
extern int centaur_init_cpu(void);
+
+#endif
+
+#ifdef CONFIG_X86_CPU_VENDOR_TRANSMETA
+
extern int transmeta_init_cpu(void);
+
+#endif
+
+#ifdef CONFIG_X86_CPU_VENDOR_RISE
+
extern int rise_init_cpu(void);
+
+#endif
+
+#ifdef CONFIG_X86_CPU_VENDOR_NEXGEN
+
extern int nexgen_init_cpu(void);
+
+#endif
+
+#ifdef CONFIG_X86_CPU_VENDOR_UMC
+
extern int umc_init_cpu(void);
+
+#endif
+
void early_cpu_detect(void);

void __init early_cpu_init(void)
{
+#ifdef CONFIG_X86_CPU_VENDOR_INTEL
intel_cpu_init();
+#endif
+#ifdef CONFIG_X86_CPU_VENDOR_CYRIX
cyrix_init_cpu();
nsc_init_cpu();
+#endif
+#ifdef CONFIG_X86_CPU_VENDOR_AMD
amd_init_cpu();
+#endif
+#ifdef CONFIG_X86_CPU_VENDOR_CENTAUR
centaur_init_cpu();
+#endif
+#ifdef CONFIG_X86_CPU_VENDOR_TRANSMETA
transmeta_init_cpu();
+#endif
+#ifdef CONFIG_X86_CPU_VENDOR_RISE
rise_init_cpu();
+#endif
+#ifdef CONFIG_X86_CPU_VENDOR_NEXGEN
nexgen_init_cpu();
+#endif
+#ifdef CONFIG_X86_CPU_VENDOR_UMC
umc_init_cpu();
+#endif
early_cpu_detect();

#ifdef CONFIG_DEBUG_PAGEALLOC
@@ -556,10 +613,14 @@
load_TR_desc();
load_LDT(&init_mm.context);

+#ifdef CONFIG_DOUBLEFAULT
+
/* Set up doublefault TSS pointer in the GDT */
__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
cpu_gdt_table[cpu][GDT_ENTRY_DOUBLEFAULT_TSS].b &= 0xfffffdff;

+#endif
+
/* Clear %fs and %gs. */
asm volatile ("xorl %eax, %eax; movl %eax, %fs; movl %eax, %gs");

diff -Naur -X ./patt ./linux-2.6.8.1/init/Kconfig ./linux-2.6.8.1_new/init/Kconfig
--- ./linux-2.6.8.1/init/Kconfig 2004-08-14 13:55:59.000000000 +0300
+++ ./linux-2.6.8.1_new/init/Kconfig 2004-08-31 21:48:02.000000000 +0300
@@ -285,6 +285,15 @@

If unsure, say N.

+config DOUBLEFAULT
+ depends on X86
+ bool "Enable doublefault exception handler" if EMBEDDED
+ default y
+ help
+ If unsure, say Y.
+
+ You will save about 10KB disabling this handler.
+
endmenu # General setup


diff -Naur -X ./patt ./linux-2.6.8.1/net/ipv4/Kconfig ./linux-2.6.8.1_new/net/ipv4/Kconfig
--- ./linux-2.6.8.1/net/ipv4/Kconfig 2004-08-14 13:55:48.000000000 +0300
+++ ./linux-2.6.8.1_new/net/ipv4/Kconfig 2004-08-31 20:15:56.000000000 +0300
@@ -261,6 +261,15 @@
gated-5). This routing protocol is not used widely, so say N unless
you want to play with it.

+config IP_IGMP
+ bool "IP: IGMP support"
+ depends on INET
+ default y
+ help
+ Internet Group Management Protocol support. Saying N here effectively
+ disables support for IP multicasting and saves about 14KB of kernel
+ size. If unsure say Y.
+
config ARPD
bool "IP: ARP daemon support (EXPERIMENTAL)"
depends on INET && EXPERIMENTAL
diff -Naur -X ./patt ./linux-2.6.8.1/net/ipv4/Makefile ./linux-2.6.8.1_new/net/ipv4/Makefile
--- ./linux-2.6.8.1/net/ipv4/Makefile 2004-08-14 13:54:52.000000000 +0300
+++ ./linux-2.6.8.1_new/net/ipv4/Makefile 2004-08-31 20:17:52.000000000 +0300
@@ -6,9 +6,10 @@
ip_input.o ip_fragment.o ip_forward.o ip_options.o \
ip_output.o ip_sockglue.o \
tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o tcp_minisocks.o \
- tcp_diag.o datagram.o raw.o udp.o arp.o icmp.o devinet.o af_inet.o igmp.o \
+ tcp_diag.o datagram.o raw.o udp.o arp.o icmp.o devinet.o af_inet.o \
sysctl_net_ipv4.o fib_frontend.o fib_semantics.o fib_hash.o

+obj-$(CONFIG_IP_IGMP) += igmp.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o
obj-$(CONFIG_IP_ROUTE_NAT) += ip_nat_dumb.o
diff -Naur -X ./patt ./linux-2.6.8.1/net/ipv4/af_inet.c ./linux-2.6.8.1_new/net/ipv4/af_inet.c
--- ./linux-2.6.8.1/net/ipv4/af_inet.c 2004-08-14 13:54:50.000000000 +0300
+++ ./linux-2.6.8.1_new/net/ipv4/af_inet.c 2004-08-31 19:51:58.000000000 +0300
@@ -379,8 +379,9 @@
long timeout;

/* Applications forget to leave groups before exiting */
+#ifdef CONFIG_IP_IGMP
ip_mc_drop_socket(sk);
-
+#endif
/* If linger is set, we don't return until the close
* is complete. Otherwise we return immediately. The
* actually closing is done the same either way.
diff -Naur -X ./patt ./linux-2.6.8.1/net/ipv4/devinet.c ./linux-2.6.8.1_new/net/ipv4/devinet.c
--- ./linux-2.6.8.1/net/ipv4/devinet.c 2004-08-14 13:54:51.000000000 +0300
+++ ./linux-2.6.8.1_new/net/ipv4/devinet.c 2004-08-31 19:49:55.000000000 +0300
@@ -165,9 +165,11 @@
#ifdef CONFIG_SYSCTL
devinet_sysctl_register(in_dev, &in_dev->cnf);
#endif
+#ifdef CONFIG_IP_IGMP
ip_mc_init_dev(in_dev);
if (dev->flags & IFF_UP)
ip_mc_up(in_dev);
+#endif
out:
return in_dev;
out_kfree:
@@ -184,7 +186,9 @@

in_dev->dead = 1;

+#ifdef CONFIG_IP_IGMP
ip_mc_destroy_dev(in_dev);
+#endif

while ((ifa = in_dev->ifa_list) != NULL) {
inet_del_ifa(in_dev, &in_dev->ifa_list, 0);
@@ -981,10 +985,14 @@
in_dev->cnf.no_xfrm = 1;
in_dev->cnf.no_policy = 1;
}
+#ifdef CONFIG_IP_IGMP
ip_mc_up(in_dev);
+#endif
break;
case NETDEV_DOWN:
+#ifdef CONFIG_IP_IGMP
ip_mc_down(in_dev);
+#endif
break;
case NETDEV_CHANGEMTU:
if (dev->mtu >= 68)
diff -Naur -X ./patt ./linux-2.6.8.1/net/ipv4/ip_sockglue.c ./linux-2.6.8.1_new/net/ipv4/ip_sockglue.c
--- ./linux-2.6.8.1/net/ipv4/ip_sockglue.c 2004-08-14 13:55:09.000000000 +0300
+++ ./linux-2.6.8.1_new/net/ipv4/ip_sockglue.c 2004-08-31 19:33:07.000000000 +0300
@@ -523,6 +523,9 @@
if (!val)
skb_queue_purge(&sk->sk_error_queue);
break;
+
+#ifdef CONFIG_IP_IGMP
+
case IP_MULTICAST_TTL:
if (sk->sk_type == SOCK_STREAM)
goto e_inval;
@@ -839,6 +842,9 @@
kfree(gsf);
break;
}
+
+#endif
+
case IP_ROUTER_ALERT:
err = ip_ra_control(sk, val ? 1 : 0, NULL);
break;
@@ -970,6 +976,9 @@
case IP_RECVERR:
val = inet->recverr;
break;
+
+#ifdef CONFIG_IP_IGMP
+
case IP_MULTICAST_TTL:
val = inet->mc_ttl;
break;
@@ -1025,6 +1034,9 @@
release_sock(sk);
return err;
}
+
+#endif
+
case IP_PKTOPTIONS:
{
struct msghdr msg;
diff -Naur -X ./patt ./linux-2.6.8.1/net/ipv4/route.c ./linux-2.6.8.1_new/net/ipv4/route.c
--- ./linux-2.6.8.1/net/ipv4/route.c 2004-08-14 13:56:23.000000000 +0300
+++ ./linux-2.6.8.1_new/net/ipv4/route.c 2004-08-31 19:46:49.000000000 +0300
@@ -1453,6 +1453,8 @@
rt->rt_type = res->type;
}

+#ifdef CONFIG_IP_IGMP
+
static int ip_route_input_mc(struct sk_buff *skb, u32 daddr, u32 saddr,
u8 tos, struct net_device *dev, int our)
{
@@ -1538,6 +1540,8 @@
return -EINVAL;
}

+#endif
+
/*
* NOTE. We drop all the packets that has local source
* addresses, because every properly looped back packet
@@ -1898,6 +1902,9 @@
route cache entry is created eventually.
*/
if (MULTICAST(daddr)) {
+
+#ifdef CONFIG_IP_IGMP
+
struct in_device *in_dev;

read_lock(&inetdev_lock);
@@ -1915,6 +1922,9 @@
}
}
read_unlock(&inetdev_lock);
+
+#endif
+
return -EINVAL;
}
return ip_route_input_slow(skb, daddr, saddr, tos, dev);
@@ -2131,7 +2141,11 @@
fib_info_put(res.fi);
res.fi = NULL;
}
- } else if (res.type == RTN_MULTICAST) {
+ }
+
+#ifdef CONFIG_IP_IGMP
+
+ else if (res.type == RTN_MULTICAST) {
flags |= RTCF_MULTICAST|RTCF_LOCAL;
if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src, oldflp->proto))
flags &= ~RTCF_LOCAL;
@@ -2145,6 +2159,8 @@
}
}

+#endif
+
rth = dst_alloc(&ipv4_dst_ops);
if (!rth)
goto e_nobufs;
diff -Naur -X ./patt ./linux-2.6.8.1/net/ipv4/udp.c ./linux-2.6.8.1_new/net/ipv4/udp.c
--- ./linux-2.6.8.1/net/ipv4/udp.c 2004-08-14 13:54:50.000000000 +0300
+++ ./linux-2.6.8.1_new/net/ipv4/udp.c 2004-08-31 19:40:19.000000000 +0300
@@ -275,6 +275,8 @@
return sk;
}

+#ifdef CONFIG_IP_IGMP
+
static inline struct sock *udp_v4_mcast_next(struct sock *sk,
u16 loc_port, u32 loc_addr,
u16 rmt_port, u32 rmt_addr,
@@ -303,6 +305,8 @@
return s;
}

+#endif
+
/*
* This routine is called by the ICMP module when it gets some
* sort of error condition. If err < 0 then the socket should
@@ -1040,6 +1044,8 @@
return 0;
}

+#ifdef CONFIG_IP_IGMP
+
/*
* Multicasts and broadcasts go to each listener.
*
@@ -1082,6 +1088,8 @@
return 0;
}

+#endif
+
/* Initialize UDP checksum. If exited with zero value (success),
* CHECKSUM_UNNECESSARY means, that no more checks are required.
* Otherwise, csum completion requires chacksumming packet body,
@@ -1116,7 +1124,6 @@
struct sock *sk;
struct udphdr *uh;
unsigned short ulen;
- struct rtable *rt = (struct rtable*)skb->dst;
u32 saddr = skb->nh.iph->saddr;
u32 daddr = skb->nh.iph->daddr;
int len = skb->len;
@@ -1140,9 +1147,14 @@
if (udp_checksum_init(skb, uh, ulen, saddr, daddr) < 0)
goto csum_error;

+#ifdef CONFIG_IP_IGMP
+
+ struct rtable *rt = (struct rtable*)skb->dst;
if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
return udp_v4_mcast_deliver(skb, uh, saddr, daddr);

+#endif
+
sk = udp_v4_lookup(saddr, uh->source, daddr, uh->dest, skb->dev->ifindex);

if (sk != NULL) {