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https://github.com/brain-hackers/u-boot-brain
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![Richard Retanubun](/assets/img/avatar_default.png)
This patch clarifies the way m68k passes linux boot argument. The one gotcha here is that the assembly instruction that the compiler uses to jump to the kernel is 'jsr' which pushes the program counter for the instruction after the jsr into the stack pointer. Signed-off-by: Richard Retanubun <RichardRetanubun@RuggedCom.com> Signed-off-by: Wolfgang Denk <wd@denx.de>
147 lines
3.7 KiB
C
Executable File
147 lines
3.7 KiB
C
Executable File
/*
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* (C) Copyright 2003
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* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <common.h>
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#include <command.h>
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#include <image.h>
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#include <zlib.h>
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#include <bzlib.h>
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#include <watchdog.h>
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#include <environment.h>
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#include <asm/byteorder.h>
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#ifdef CONFIG_SHOW_BOOT_PROGRESS
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# include <status_led.h>
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#endif
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DECLARE_GLOBAL_DATA_PTR;
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#define PHYSADDR(x) x
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#define LINUX_MAX_ENVS 256
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#define LINUX_MAX_ARGS 256
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static ulong get_sp (void);
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static void set_clocks_in_mhz (bd_t *kbd);
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void arch_lmb_reserve(struct lmb *lmb)
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{
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ulong sp;
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/*
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* Booting a (Linux) kernel image
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*
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* Allocate space for command line and board info - the
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* address should be as high as possible within the reach of
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* the kernel (see CONFIG_SYS_BOOTMAPSZ settings), but in unused
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* memory, which means far enough below the current stack
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* pointer.
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*/
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sp = get_sp();
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debug ("## Current stack ends at 0x%08lx ", sp);
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/* adjust sp by 1K to be safe */
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sp -= 1024;
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lmb_reserve(lmb, sp, (CONFIG_SYS_SDRAM_BASE + gd->ram_size - sp));
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}
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int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
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{
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ulong rd_len;
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ulong initrd_start, initrd_end;
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int ret;
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ulong cmd_start, cmd_end;
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ulong bootmap_base;
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bd_t *kbd;
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void (*kernel) (bd_t *, ulong, ulong, ulong, ulong);
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struct lmb *lmb = &images->lmb;
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if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
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return 1;
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bootmap_base = getenv_bootm_low();
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/* allocate space and init command line */
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ret = boot_get_cmdline (lmb, &cmd_start, &cmd_end, bootmap_base);
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if (ret) {
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puts("ERROR with allocation of cmdline\n");
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goto error;
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}
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/* allocate space for kernel copy of board info */
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ret = boot_get_kbd (lmb, &kbd, bootmap_base);
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if (ret) {
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puts("ERROR with allocation of kernel bd\n");
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goto error;
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}
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set_clocks_in_mhz(kbd);
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kernel = (void (*)(bd_t *, ulong, ulong, ulong, ulong))images->ep;
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rd_len = images->rd_end - images->rd_start;
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ret = boot_ramdisk_high (lmb, images->rd_start, rd_len,
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&initrd_start, &initrd_end);
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if (ret)
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goto error;
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debug("## Transferring control to Linux (at address %08lx) ...\n",
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(ulong) kernel);
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show_boot_progress (15);
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/*
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* Linux Kernel Parameters (passing board info data):
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* sp+00: Ignore, side effect of using jsr to jump to kernel
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* sp+04: ptr to board info data
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* sp+08: initrd_start or 0 if no initrd
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* sp+12: initrd_end - unused if initrd_start is 0
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* sp+16: Start of command line string
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* sp+20: End of command line string
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*/
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(*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
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/* does not return */
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error:
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return 1;
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}
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static ulong get_sp (void)
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{
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ulong sp;
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asm("movel %%a7, %%d0\n"
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"movel %%d0, %0\n": "=d"(sp): :"%d0");
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return sp;
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}
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static void set_clocks_in_mhz (bd_t *kbd)
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{
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char *s;
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if ((s = getenv("clocks_in_mhz")) != NULL) {
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/* convert all clock information to MHz */
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kbd->bi_intfreq /= 1000000L;
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kbd->bi_busfreq /= 1000000L;
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}
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}
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