* Copyright (c) 2011 Marek Vasut <marek.vasut@gmail.com>
* on behalf of DENX Software Engineering GmbH
*
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that 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
+ * SPDX-License-Identifier: GPL-2.0+
*/
#include <asm-offsets.h>
.globl _TEXT_BASE
_TEXT_BASE:
+#ifdef CONFIG_SPL_TEXT_BASE
+ .word CONFIG_SPL_TEXT_BASE
+#else
.word CONFIG_SYS_TEXT_BASE
+#endif
/*
* These are defined in the board-specific linker script.
.globl _bss_end_ofs
_bss_end_ofs:
- .word __bss_end__ - _start
+ .word __bss_end - _start
.globl _end_ofs
_end_ofs:
*/
_reset:
+ /*
+ * If the CPU is configured in "Wait JTAG connection mode", the stack
+ * pointer is not configured and is zero. This will cause crash when
+ * trying to push data onto stack right below here. Load the SP and make
+ * it point to the end of OCRAM if the SP is zero.
+ */
+ cmp sp, #0x00000000
+ ldreq sp, =CONFIG_SYS_INIT_SP_ADDR
+
/*
* Store all registers on old stack pointer, this will allow us later to
* return to the BootROM and let the BootROM load U-Boot into RAM.
+ *
+ * WARNING: Register r0 and r1 are used by the BootROM to pass data
+ * to the called code. Register r0 will contain arbitrary
+ * data that are set in the BootStream. In case this code
+ * was started with CALL instruction, register r1 will contain
+ * pointer to the return value this function can then set.
+ * The code below MUST NOT CHANGE register r0 and r1 !
*/
push {r0-r12,r14}
- /* save control register c1 */
- mrc p15, 0, r0, c1, c0, 0
- push {r0}
+ /* Save control register c1 */
+ mrc p15, 0, r2, c1, c0, 0
+ push {r2}
- /*
- * set the cpu to SVC32 mode and store old CPSR register content
- */
- mrs r0,cpsr
- push {r0}
- bic r0,r0,#0x1f
- orr r0,r0,#0xd3
- msr cpsr,r0
-
- /*
- * we do sys-critical inits only at reboot,
- * not when booting from ram!
- */
-#ifndef CONFIG_SKIP_LOWLEVEL_INIT
- bl cpu_init_crit
-#endif
+ /* Set the cpu to SVC32 mode and store old CPSR register content. */
+ mrs r2, cpsr
+ push {r2}
+ bic r2, r2, #0x1f
+ orr r2, r2, #0xd3
+ msr cpsr, r2
bl board_init_ll
- /*
- * restore bootrom's cpu mode (especially FIQ)
- */
- pop {r0}
- msr cpsr,r0
+ /* Restore BootROM's CPU mode (especially FIQ). */
+ pop {r2}
+ msr cpsr,r2
/*
- * restore c1 register
- * (especially set exception vector location back to
- * bootrom space which is required by bootrom for USB boot)
+ * Restore c1 register. Especially set exception vector location
+ * back to BootROM space which is required by bootrom for USB boot.
*/
- pop {r0}
- mcr p15, 0, r0, c1, c0, 0
+ pop {r2}
+ mcr p15, 0, r2, c1, c0, 0
pop {r0-r12,r14}
- bx lr
-
-/*
- *************************************************************************
- *
- * CPU_init_critical registers
- *
- * setup important registers
- * setup memory timing
- *
- *************************************************************************
- */
-#ifndef CONFIG_SKIP_LOWLEVEL_INIT
-cpu_init_crit:
- /*
- * flush v4 I/D caches
- */
- mov r0, #0
- mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
- mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
/*
- * disable MMU stuff and caches
+ * In case this code was started by the CALL instruction, the register
+ * r0 is examined by the BootROM after this code returns. The value in
+ * r0 must be set to 0 to indicate successful return.
*/
- mrc p15, 0, r0, c1, c0, 0
- bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */
- bic r0, r0, #0x00000087 /* clear bits 7, 2:0 (B--- -CAM) */
- orr r0, r0, #0x00000002 /* set bit 2 (A) Align */
- orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */
- mcr p15, 0, r0, c1, c0, 0
-
- mov pc, lr /* back to my caller */
+ mov r0, #0
- .align 5
-#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
+ bx lr
_hang:
ldr sp, _TEXT_BASE /* switch to abort stack */