ARM: atmel: at91sam9m10g45ek: enable SPL
RFC PATCH 1/1 ARM: atmel: at91sam9m10g45ek: enable SPL
Supports boot up from NAND flash with software ECC eanbled. And supports boot up from SD/MMC card with FAT file system.
As the boot from SD/MMC card with FAT file system, the BSS segment is too big to fit into SRAM, so, use the lds to put it into SDRAM. So, we need to initialize the SDRAM as soon as possible. Borrow the low level init code from <arm/arm/cpu/armv7/lowlevel_init.S> for this purpose.
---
arch/arm/Kconfig | 1 + arch/arm/cpu/arm926ejs/at91/Makefile | 4 ++ arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S | 37 ++++++++++++ arch/arm/cpu/at91-common/spl_at91.c | 10 ++++ arch/arm/cpu/at91-common/u-boot-spl-arm9.lds | 48 +++++++++++++++ board/atmel/at91sam9m10g45ek/at91sam9m10g45ek.c | 80 +++++++++++++++++++++++++ configs/at91sam9m10g45ek_mmc_defconfig | 5 +- configs/at91sam9m10g45ek_nandflash_defconfig | 5 +- include/configs/at91sam9m10g45ek.h | 64 ++++++++++++++++++++ 9 files changed, 250 insertions(+), 4 deletions(-) create mode 100644 arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S create mode 100644 arch/arm/cpu/at91-common/u-boot-spl-arm9.lds
arch/arm/Kconfig +1 -0
@@ -141,6 +141,7 @@ config TARGET_AT91SAM9263EK config TARGET_AT91SAM9M10G45EK bool "Support at91sam9m10g45ek" select CPU_ARM926EJS + select SUPPORT_SPL config TARGET_AT91SAM9N12EK bool "Support at91sam9n12ek"
arch/arm/cpu/arm926ejs/at91/Makefile +4 -0
@@ -25,5 +25,9 @@ obj-y += reset.o obj-y += timer.o ifndef CONFIG_SKIP_LOWLEVEL_INIT +ifdef CONFIG_SPL_BUILD +obj-y += spl_lowlevel_init.o +else obj-y += lowlevel_init.o endif +endif
arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S new file +37 -0
@@ -0,0 +1,37 @@ +/* + * A lowlevel_init function that sets up the stack to call a C function to + * perform further init. + * + * (C) Copyright 2010 + * Texas Instruments, <www.ti.com> + * + * Author : + * Aneesh V <[email protected]> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <asm-offsets.h> +#include <config.h> +#include <linux/linkage.h> + +ENTRY(lowlevel_init) + /* + * Setup a temporary stack + */ + ldr sp, =CONFIG_SYS_INIT_SP_ADDR + bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ + + ldr r9, =gdata + + /* + * Save the old lr(passed in ip) and the current lr to stack + */ + push {ip, lr} + + /* + * go setup pll, mux, memory + */ + bl s_init + pop {ip, pc} +ENDPROC(lowlevel_init)
arch/arm/cpu/at91-common/spl_at91.c +10 -0
@@ -71,7 +71,17 @@ void __weak at91_spl_board_init(void) { } +#ifndef CONFIG_SKIP_LOWLEVEL_INIT +__weak void spl_board_init (void ) +{ +} +#endif + +#ifdef CONFIG_SKIP_LOWLEVEL_INIT void spl_board_init(void) +#else +void s_init(void) +#endif {struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC ;
arch/arm/cpu/at91-common/u-boot-spl-arm9.lds new file +48 -0
48 lines not on this page · raw message
board/atmel/at91sam9m10g45ek/at91sam9m10g45ek.c +80 -0
98 lines not on this page · raw message
configs/at91sam9m10g45ek_mmc_defconfig +3 -2
@@ -1,3 +1,4 @@ +CONFIG_SPL=y CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9M10G45,SYS_USE_MMC" -CONFIG_ARM=y -CONFIG_TARGET_AT91SAM9M10G45EK=y ++S:CONFIG_ARM=y ++S:CONFIG_TARGET_AT91SAM9M10G45EK=y
configs/at91sam9m10g45ek_nandflash_defconfig +3 -2
@@ -1,3 +1,4 @@ +CONFIG_SPL=y CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9M10G45,SYS_USE_NANDFLASH" -CONFIG_ARM=y -CONFIG_TARGET_AT91SAM9M10G45EK=y ++S:CONFIG_ARM=y ++S:CONFIG_TARGET_AT91SAM9M10G45EK=y
include/configs/at91sam9m10g45ek.h +64 -0
83 lines not on this page · raw message
Signature · 1 line
2.1.0.24.g4109c28
RFC PATCH 1/1 ARM: atmel: at91sam9m10g45ek: enable SPL
Hello Bo,
Am 29.12.2014 08:53, schrieb Bo Shen:
Quoted 25 lines
Supports boot up from NAND flash with software ECC eanbled. And supports boot up from SD/MMC card with FAT file system.
As the boot from SD/MMC card with FAT file system, the BSS segment is too big to fit into SRAM, so, use the lds to put it into SDRAM. So, we need to initialize the SDRAM as soon as possible. Borrow the low level init code from <
arm/arm/cpu/armv7/lowlevel_init.S> for this purpose.Signed-off-by Bo Shen <[email protected]>---
arch/arm/Kconfig | 1 + arch/arm/cpu/arm926ejs/at91/Makefile | 4 ++ arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S | 37 ++++++++++++ arch/arm/cpu/at91-common/spl_at91.c | 10 ++++ arch/arm/cpu/at91-common/u-boot-spl-arm9.lds | 48 +++++++++++++++ board/atmel/at91sam9m10g45ek/at91sam9m10g45ek.c | 80 +++++++++++++++++++++++++ configs/at91sam9m10g45ek_mmc_defconfig | 5 +- configs/at91sam9m10g45ek_nandflash_defconfig | 5 +- include/configs/at91sam9m10g45ek.h | 64 ++++++++++++++++++++ 9 files changed, 250 insertions(+), 4 deletions(-)create mode 100644
arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.Screate mode 100644arch/arm/cpu/at91-common/u-boot-spl-arm9.lds
[...]
Quoted 33 lines
arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S new file +27
-0@@ -0,0 +1,37 @@ +/* + * A lowlevel_init function that sets up the stack to call a C function to + * perform further init. + * + * (C) Copyright 2010 + * Texas Instruments, <www.ti.com> + * + * Author : + * Aneesh V <[email protected]> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <asm-offsets.h> +#include <config.h> +#include <linux/linkage.h> + +ENTRY(lowlevel_init) + /* + * Setup a temporary stack + */ + ldr sp, =CONFIG_SYS_INIT_SP_ADDR + bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ + + ldr r9, =gdata + + /*
arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S line 37
Quoted 10 lines
arch/arm/cpu/arm926ejs/at91/spl_lowlevel_init.S new file +10
-0+ * Save the old lr(passed in ip) and the current lr to stack + */ + push {ip, lr} + + /* + * go setup pll, mux, memory + */ + bl s_init + pop {ip, pc} +ENDPROC(lowlevel_init)
Hmm ... we have SPL support for at91sam9* boards without
such a file in U-Boot (and without an arch/arm/cpu/at91-common/u-boot-spl-arm9.lds), see for example:
The "spl_board_init" is called from ./common/spl/spl.c from "board_init_r" which is called from "board_init_f" in ./arch/arm/lib/spl.c, which is called from ./arch/arm/lib/crt0.S
Is this new file really needed? It should possible to remove CONFIG_SKIP_LOWLEVEL_INIT
in include/configs/at91sam9m10g45ek.h ...
Quoted 11 lines
arch/arm/cpu/at91-common/spl_at91.c +3
-0@@ -71,7 +71,17 @@ void __weak at91_spl_board_init(void) { } +#ifndef CONFIG_SKIP_LOWLEVEL_INIT +__weak void spl_board_init (void ) +{
arch/arm/cpu/at91-common/spl_at91.c void __weak at91_spl_board_init(void) · line 86
Quoted 10 lines
arch/arm/cpu/at91-common/spl_at91.c +7
-0+} +#endif + +#ifdef CONFIG_SKIP_LOWLEVEL_INIT void spl_board_init(void) +#else +void s_init(void) +#endif {struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC ;
... and adding this "ifdefs" could be prevented ...
What do you think?
Quoted 5 lines · Ah! you
As the boot from SD/MMC card with FAT file system, the BSS segment is too big to fit into SRAM, so, use the lds to put it into SDRAM. So, we need to initialize the SDRAM as soon as possible. Borrow the low level init code from <
arm/arm/cpu/armv7/lowlevel_init.S> for this purpose.
Hmm... maybe we can include this in the existing code? So we have BSS for all at91 boards in RAM?
Or, if not possible, we should convert the existing boards into your framework ... if you can prepare such a patch I can test it on the corvus, taurus and axm boards ...
bye,
Heiko
Quoted 273 lines
arch/arm/cpu/at91-common/u-boot-spl-arm9.lds new file +48
-0@@ -0,0 +1,48 @@ +/* + * Copyright (C) 2014 Atmel Corporation + * Bo Shen <[email protected]> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +MEMORY { .sram : ORIGIN = CONFIG_SPL_TEXT_BASE, \ + LENGTH = CONFIG_SPL_MAX_SIZE } +MEMORY { .sdram : ORIGIN = CONFIG_SPL_BSS_START_ADDR, \ + LENGTH = CONFIG_SPL_BSS_MAX_SIZE } + +OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm") +OUTPUT_ARCH(arm) +ENTRY(_start) +SECTIONS +{ + .text : + { + __start = .; + *(.vectors) + arch/arm/cpu/arm926ejs/start.o (.text*) + *(.text*) + } >.sram + + . = ALIGN(4); + .rodata : { *(SORT_BY_ALIGNMENT(.rodata*)) } >.sram + + . = ALIGN(4); + .data : { *(SORT_BY_ALIGNMENT(.data*)) } >.sram + + . = ALIGN(4); + __image_copy_end = .; + + .end : + { + *(.__end) + } >.sram + + .bss : + { + . = ALIGN(4); + __bss_start = .; + *(.bss*) + . = ALIGN(4); + __bss_end = .; + } >.sdram +}board/atmel/at91sam9m10g45ek/at91sam9m10g45ek.c +80
-0@@ -8,6 +8,7 @@#include <common.h> #include <asm/io.h> +#include <asm/arch/clk.h> #include <asm/arch/at91sam9g45_matrix.h> #include <asm/arch/at91sam9_smc.h> #include <asm/arch/at91_common.h> @@ -15,6 +16,7 @@#include <asm/arch/gpio.h> #include <asm/arch/clk.h> #include <lcd.h> +#include <linux/mtd/nand.h> #include <atmel_lcdc.h> #include <atmel_mci.h> #if defined(CONFIG_RESET_PHY_R ) && defined(CONFIG_MACB )@@ -71,6 +73,84 @@ void at91sam9m10g45ek_nand_hw_init(void) }#endif +#if defined(CONFIG_SPL_BUILD ) +#include <spl.h> +#include <nand.h> + +void at91_spl_board_init (void ) +{ +/* +* On the at91sam9m10g45ek board, the chip wm9711 stays in the +* test mode, so it needs do some action to exit test mode. +*/ +at91_periph_clk_enable (ATMEL_ID_PIODE ); +at91_set_gpio_output (AT91_PIN_PD7 ,0 ); +at91_set_gpio_output (AT91_PIN_PD8 ,0 ); +at91_set_pio_pullup (AT91_PIO_PORTD ,7 ,1 ); +at91_set_pio_pullup (AT91_PIO_PORTD ,8 ,1 ); + +#ifdef CONFIG_SYS_USE_MMC +at91_mci_hw_init (); +#elif CONFIG_SYS_USE_NANDFLASH +at91sam9m10g45ek_nand_hw_init (); +#endif +} + +#include <asm/arch/atmel_mpddrc.h> +static void ddr2_conf (struct atmel_mpddr *ddr2) +{ + ddr2->md = (ATMEL_MPDDRC_MD_DBW_16_BITS |ATMEL_MPDDRC_MD_DDR2_SDRAM ); + + ddr2->cr = (ATMEL_MPDDRC_CR_NC_COL_10 | +ATMEL_MPDDRC_CR_NR_ROW_14 | +ATMEL_MPDDRC_CR_DQMS_SHARED | +ATMEL_MPDDRC_CR_CAS_DDR_CAS3 ); + + ddr2->rtr =0x24b ; + + ddr2->tpr0 = (6 <<ATMEL_MPDDRC_TPR0_TRAS_OFFSET |/* 6*7.5 = 45 ns */ +2 <<ATMEL_MPDDRC_TPR0_TRCD_OFFSET |/* 2*7.5 = 15 ns */ +2 <<ATMEL_MPDDRC_TPR0_TWR_OFFSET |/* 2*7.5 = 15 ns */ +8 <<ATMEL_MPDDRC_TPR0_TRC_OFFSET |/* 8*7.5 = 60 ns */ +2 <<ATMEL_MPDDRC_TPR0_TRP_OFFSET |/* 2*7.5 = 15 ns */ +1 <<ATMEL_MPDDRC_TPR0_TRRD_OFFSET |/* 1*7.5= 7.5 ns*/ +1 <<ATMEL_MPDDRC_TPR0_TWTR_OFFSET |/* 1 clk cycle */ +2 <<ATMEL_MPDDRC_TPR0_TMRD_OFFSET );/* 2 clk cycles */ + + ddr2->tpr1 = (2 <<ATMEL_MPDDRC_TPR1_TXP_OFFSET |/* 2*7.5 = 15 ns */ +200 <<ATMEL_MPDDRC_TPR1_TXSRD_OFFSET | +16 <<ATMEL_MPDDRC_TPR1_TXSNR_OFFSET | +14 <<ATMEL_MPDDRC_TPR1_TRFC_OFFSET ); + + ddr2->tpr2 = (1 <<ATMEL_MPDDRC_TPR2_TRTP_OFFSET | +0 <<ATMEL_MPDDRC_TPR2_TRPA_OFFSET | +7 <<ATMEL_MPDDRC_TPR2_TXARDS_OFFSET | +2 <<ATMEL_MPDDRC_TPR2_TXARD_OFFSET ); +} + +void mem_init (void ) +{ +struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC ; +struct at91_matrix *mat = (struct at91_matrix *)ATMEL_BASE_MATRIX ; +struct atmel_mpddr ddr2; +unsigned long csa; + +ddr2_conf (&ddr2); + +/* enable DDR2 clock */ +writel (0x4 , &pmc->scer); + +/* Chip select 1 is for DDR2/SDRAM */ + csa =readl (&mat->ebicsa); + csa |=AT91_MATRIX_EBI_CS1A_SDRAMC ; + csa &= ~AT91_MATRIX_EBI_VDDIOMSEL_3_3V ; +writel (csa, &mat->ebicsa); + +/* DDRAM2 Controller initialize */ +ddr2_init (ATMEL_BASE_CS6 , &ddr2); +} +#endif +#ifdef CONFIG_CMD_USB static void at91sam9m10g45ek_usb_hw_init (void ) {configs/at91sam9m10g45ek_mmc_defconfig +3
-2@@ -1,3 +1,4 @@ +CONFIG_SPL=y CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9M10G45,SYS_USE_MMC" -CONFIG_ARM=y -CONFIG_TARGET_AT91SAM9M10G45EK=y ++S:CONFIG_ARM=y ++S:CONFIG_TARGET_AT91SAM9M10G45EK=yconfigs/at91sam9m10g45ek_nandflash_defconfig +3
-2@@ -1,3 +1,4 @@ +CONFIG_SPL=y CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9M10G45,SYS_USE_NANDFLASH" -CONFIG_ARM=y -CONFIG_TARGET_AT91SAM9M10G45EK=y ++S:CONFIG_ARM=y ++S:CONFIG_TARGET_AT91SAM9M10G45EK=yinclude/configs/at91sam9m10g45ek.h +64
-0@@ -26,7 +26,9 @@#define CONFIG_CMDLINE_TAG /* enable passing of ATAGs */ #define CONFIG_SETUP_MEMORY_TAGS #define CONFIG_INITRD_TAG +#ifndef CONFIG_SPL_BUILD #define CONFIG_SKIP_LOWLEVEL_INIT +#endif #define CONFIG_BOARD_EARLY_INIT_F #define CONFIG_DISPLAY_CPUINFO @@ -98,8 +100,12 @@#define CONFIG_SYS_SDRAM_BASE ATMEL_BASE_CS6#define CONFIG_SYS_SDRAM_SIZE 0x08000000 +#ifdef CONFIG_SPL_BUILD +#define CONFIG_SYS_INIT_SP_ADDR 0x310000 +#else #define CONFIG_SYS_INIT_SP_ADDR \ (CONFIG_SYS_SDRAM_BASE + 4 * 1024 - GENERATED_GBL_DATA_SIZE) +#endif /* NAND flash */ #ifdef CONFIG_CMD_NAND @@ -203,4 +209,62 @@*/ #define CONFIG_SYS_MALLOC_LEN ROUND(3 * CONFIG_ENV_SIZE + 128*1024, 0x1000) +/* Defines for SPL */ +#define CONFIG_SPL_FRAMEWORK +#define CONFIG_SPL_TEXT_BASE 0x300000 +#define CONFIG_SPL_MAX_SIZE 0x010000 + +#define CONFIG_SPL_BSS_START_ADDR 0x70000000 +#define CONFIG_SPL_BSS_MAX_SIZE 0x00080000 +#define CONFIG_SYS_SPL_MALLOC_START 0x70080000 +#define CONFIG_SYS_SPL_MALLOC_SIZE 0x00080000 + +#define CONFIG_SPL_LIBCOMMON_SUPPORT +#define CONFIG_SPL_LIBGENERIC_SUPPORT +#define CONFIG_SPL_SERIAL_SUPPORT +#define CONFIG_SPL_GPIO_SUPPORT + +#define CONFIG_SPL_BOARD_INIT +#define CONFIG_SYS_MONITOR_LEN 0x80000 + +#ifdef CONFIG_SYS_USE_MMC +#define CONFIG_SPL_LDSCRIPT arch/arm/cpu/at91-common/u-boot-spl-arm9.lds +#define CONFIG_SPL_MMC_SUPPORT +#define CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS 0x400 +#define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR 0x200 +#define CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 1 +#define CONFIG_SPL_FS_LOAD_PAYLOAD_NAME "u-boot.img" +#define CONFIG_SPL_FAT_SUPPORT +#define CONFIG_SPL_LIBDISK_SUPPORT + +#elif CONFIG_SYS_USE_NANDFLASH +#define CONFIG_SYS_NAND_ENABLE_PIN_SPL (2*32 + 14) +#define CONFIG_SPL_NAND_SUPPORT +#define CONFIG_SPL_NAND_DRIVERS +#define CONFIG_SPL_NAND_BASE +#define CONFIG_SPL_NAND_ECC +#define CONFIG_SPL_NAND_SOFTECC +#define CONFIG_SYS_NAND_U_BOOT_OFFS 0x40000 +#define CONFIG_SYS_NAND_U_BOOT_SIZE 0x80000 +#define CONFIG_SYS_NAND_5_ADDR_CYCLE + +#define CONFIG_SYS_NAND_PAGE_SIZE 0x800 +#define CONFIG_SYS_NAND_BLOCK_SIZE 0x20000 +#define CONFIG_SYS_NAND_PAGE_COUNT 64 +#define CONFIG_SYS_NAND_BAD_BLOCK_POS NAND_LARGE_BADBLOCK_POS +#define CONFIG_SYS_NAND_ECCSIZE 256 +#define CONFIG_SYS_NAND_ECCBYTES 3 +#define CONFIG_SYS_NAND_OOBSIZE 64 +#define CONFIG_SYS_NAND_ECCPOS { 40, 41, 42, 43, 44, 45, 46, 47, \ + 48, 49, 50, 51, 52, 53, 54, 55, \ + 56, 57, 58, 59, 60, 61, 62, 63, } +#endif + +#define CONFIG_SPL_ATMEL_SIZE +#define CONFIG_SYS_MASTER_CLOCK 132096000 +#define CONFIG_SYS_AT91_PLLA 0x20c73f03 +#define CONFIG_SYS_MCKR 0x1301 +#define CONFIG_SYS_MCKR_CSS 0x1302 + +#define ATMEL_BASE_MPDDRC ATMEL_BASE_DDRSDRC0#endif
Signature · 2 lines
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
RFC PATCH 1/1 ARM: atmel: at91sam9m10g45ek: enable SPL
Hi Heiko,
Quoted 14 lines · Heiko Schocher
arch/arm/cpu/at91-common/spl_at91.c void __weak at91_spl_board_init(void) · line 86
Quoted 7 lines
arch/arm/cpu/at91-common/spl_at91.c +4
-0+#ifdef CONFIG_SKIP_LOWLEVEL_INIT void spl_board_init(void) +#else +void s_init(void) +#endif {struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC ;... and adding this "ifdefs" could be prevented ...
What do you think?
Ah! you wrote:
Quoted 7 lines
Quoted 5 lines
As the boot from SD/MMC card with FAT file system, the BSS segment is too big to fit into SRAM, so, use the lds to put it into SDRAM. So, we need to initialize the SDRAM as soon as possible. Borrow the low level init code from <
arm/arm/cpu/armv7/lowlevel_init.S> for this purpose.Hmm... maybe we can include this in the existing code? So we
The existed code is located in <arch/arm/cpu/armv7> directory, I think it is difficult to include it.
I think we can put it into <arch/arm/cpu/arm926ejs> directory, I am not sure it will help others. As other SoC has low level init code. Or, as the patch, put it into <arch/arm/cpu/arm926ejs/at91> directory for at91 series only.
Quoted 1 line
have BSS for all at91 boards in RAM?
It depends, we still can put the BSS into SRAM use the common u-boot-spl.lds.
Only put BSS into SDRAM/DDR, when use u-boot-spl-arm9.lds.
Quoted 3 lines
Or, if not possible, we should convert the existing boards into your framework ... if you can prepare such a patch I can test it on the corvus, taurus and axm boards ...
If the upper method for low level initialize code is chosen, I will prepare such patch for the boards you mentioned.
Quoted 2 lines
bye,
Heiko
Best Regards,
Bo Shen
RFC PATCH 1/1 ARM: atmel: at91sam9m10g45ek: enable SPL
Hello Bo,
Am 05.01.2015 09:19, schrieb Bo Shen:
Quoted 23 lines
Hi Heiko,
Quoted 20 lines · Heiko Schocher
arch/arm/cpu/at91-common/spl_at91.c void __weak at91_spl_board_init(void) · line 86
Quoted 7 lines
arch/arm/cpu/at91-common/spl_at91.c +4
-0+#ifdef CONFIG_SKIP_LOWLEVEL_INIT void spl_board_init(void) +#else +void s_init(void) +#endif {struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC ;... and adding this "ifdefs" could be prevented ...
What do you think?
Quoted 5 lines · Ah! you
As the boot from SD/MMC card with FAT file system, the BSS segment is too big to fit into SRAM, so, use the lds to put it into SDRAM. So, we need to initialize the SDRAM as soon as possible. Borrow the low level init code from <
arm/arm/cpu/armv7/lowlevel_init.S> for this purpose.
Quoted 5 lines
Quoted 1 line
Hmm... maybe we can include this in the existing code? So we
The existed code is located in <
arch/arm/cpu/armv7> directory, I think it is difficult to include it.I think we can put it into <
arch/arm/cpu/arm926ejs> directory, I am not sure it will help others. As other SoC has low level init code. Or, as the patch, put it into <arch/arm/cpu/arm926ejs/at91> directory for at91 series only.
I thought with "maybe we can include this in the existing code?"
adding into existing at91 code the earlier RAM initialization and using BSS in RAM, without needing CONFIG_SKIP_LOWLEVEL_INIT ...
Quoted 4 lines
Quoted 1 line
have BSS for all at91 boards in RAM?
It depends, we still can put the BSS into SRAM use the common
u-boot-spl.lds. Only put BSS into SDRAM/DDR, when useu-boot-spl-arm9.lds.
Ok, Yes.
Quoted 5 lines
Quoted 3 lines
Or, if not possible, we should convert the existing boards into your framework ... if you can prepare such a patch I can test it on the corvus, taurus and axm boards ...
If the upper method for low level initialize code is chosen, I will prepare such patch for the boards you mentioned.
I vote for having only one way for the at91 boards, so your approach is also OK for me ... if andreas is fine with it, please feel free to send me a patch for testing on the mentioned boards, thanks!
bye,
Heiko
Signature · 2 lines
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany