linux/arch/mips/powertv/init.c
David VomLehn 0d59050496 MIPS: PowerTV: Simplify command line handling and needed config changes
Additional changes to Youichi Yuasa's command line simplication code

The PowerTV platform uses a non-standard way to get the kernel command
line--we insert a built-in command line into arcs_cmdline and to
get additional command line information from the bootloader via a
pointer in the a1 register. It is necessary to insert a space between
to the two strings or the last argument from arcs_cmdline and the first
argument from the bootloader may be inadvertantly combined.

It is also necessary to set CONFIG_CMDLINE_BOOL to "y" and to set the
default command line to an empty string to get the simplified code to
work properly in the PowerTV environment.

Signed-off-by: David VomLehn <dvomlehn@cisco.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1438/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-08-05 13:26:02 +01:00

132 lines
3.4 KiB
C

/*
* Copyright (C) 1999, 2000, 2004, 2005 MIPS Technologies, Inc.
* All rights reserved.
* Authors: Carsten Langgaard <carstenl@mips.com>
* Maciej W. Rozycki <macro@mips.com>
* Portions copyright (C) 2009 Cisco Systems, Inc.
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* PROM library initialisation code.
*/
#include <linux/init.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <asm/bootinfo.h>
#include <linux/io.h>
#include <asm/system.h>
#include <asm/cacheflush.h>
#include <asm/traps.h>
#include <asm/mips-boards/prom.h>
#include <asm/mips-boards/generic.h>
#include <asm/mach-powertv/asic.h>
static int *_prom_envp;
unsigned long _prom_memsize;
/*
* YAMON (32-bit PROM) pass arguments and environment as 32-bit pointer.
* This macro take care of sign extension, if running in 64-bit mode.
*/
#define prom_envp(index) ((char *)(long)_prom_envp[(index)])
char *prom_getenv(char *envname)
{
char *result = NULL;
if (_prom_envp != NULL) {
/*
* Return a pointer to the given environment variable.
* In 64-bit mode: we're using 64-bit pointers, but all pointers
* in the PROM structures are only 32-bit, so we need some
* workarounds, if we are running in 64-bit mode.
*/
int i, index = 0;
i = strlen(envname);
while (prom_envp(index)) {
if (strncmp(envname, prom_envp(index), i) == 0) {
result = prom_envp(index + 1);
break;
}
index += 2;
}
}
return result;
}
/* TODO: Verify on linux-mips mailing list that the following two */
/* functions are correct */
/* TODO: Copy NMI and EJTAG exception vectors to memory from the */
/* BootROM exception vectors. Flush their cache entries. test it. */
static void __init mips_nmi_setup(void)
{
void *base;
#if defined(CONFIG_CPU_MIPS32_R1)
base = cpu_has_veic ?
(void *)(CAC_BASE + 0xa80) :
(void *)(CAC_BASE + 0x380);
#elif defined(CONFIG_CPU_MIPS32_R2)
base = (void *)0xbfc00000;
#else
#error NMI exception handler address not defined
#endif
}
static void __init mips_ejtag_setup(void)
{
void *base;
#if defined(CONFIG_CPU_MIPS32_R1)
base = cpu_has_veic ?
(void *)(CAC_BASE + 0xa00) :
(void *)(CAC_BASE + 0x300);
#elif defined(CONFIG_CPU_MIPS32_R2)
base = (void *)0xbfc00480;
#else
#error EJTAG exception handler address not defined
#endif
}
void __init prom_init(void)
{
int prom_argc;
char *prom_argv;
prom_argc = fw_arg0;
prom_argv = (char *) fw_arg1;
_prom_envp = (int *) fw_arg2;
_prom_memsize = (unsigned long) fw_arg3;
board_nmi_handler_setup = mips_nmi_setup;
board_ejtag_handler_setup = mips_ejtag_setup;
if (prom_argc == 1) {
strlcat(arcs_cmdline, " ", COMMAND_LINE_SIZE);
strlcat(arcs_cmdline, prom_argv, COMMAND_LINE_SIZE);
}
configure_platform();
prom_meminit();
#ifndef CONFIG_BOOTLOADER_DRIVER
pr_info("\nBootloader driver isn't loaded...\n");
#endif
}