[U-Boot] [PATCH 1/1] ARM: mxs: Get boot mode from OCRAM

[U-Boot] [PATCH 1/1] ARM: mxs: Get boot mode from OCRAM

[Jörg Krause]

Reading the boot mode pins after power-up does not necessarily represent the
boot mode used by the ROM loader. For example the state of a pin may have
changed because a recovery switch which was pressed to enter USB mode is
already released after plugging in USB.

The ROM loader stores the value a fixed address in OCRAM. Use this value
instead of reading the boot map pins.

The GLOBAL_BOOT_MODE_ADDR for i.MX28 is taken from an U-Boot patch for the
MX28EVK:
http://repository.timesys.com/buildsources/u/u-boot/u-boot-2009.08/u-boot-2009.08-mx28-201012211513.patch

Leave the boot mode detection for the i.MX23 untouched. Someone has to test
whether the i.MX ROM loader does also store the boot mode in OCRAM and if the
address match.

This patch superseeds my incorrect patch:
ARM: mxs: get boot mode from OTP
http://patchwork.ozlabs.org/patch/454930/

Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>
Cc: Stefano Babic <sbabic@denx.de>
---
 arch/arm/cpu/arm926ejs/mxs/spl_boot.c | 29 ++++++-----------------------
 1 file changed, 6 insertions(+), 23 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
index d7956e5..eb8669b 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
@@ -49,13 +49,6 @@ static const iomux_cfg_t iomux_boot[] = {
 	MX23_PAD_LCD_D03__GPIO_1_3 | MUX_CONFIG_BOOTMODE_PAD,
 	MX23_PAD_LCD_D04__GPIO_1_4 | MUX_CONFIG_BOOTMODE_PAD,
 	MX23_PAD_LCD_D05__GPIO_1_5 | MUX_CONFIG_BOOTMODE_PAD,
-#elif defined(CONFIG_MX28)
-	MX28_PAD_LCD_D00__GPIO_1_0 | MUX_CONFIG_BOOTMODE_PAD,
-	MX28_PAD_LCD_D01__GPIO_1_1 | MUX_CONFIG_BOOTMODE_PAD,
-	MX28_PAD_LCD_D02__GPIO_1_2 | MUX_CONFIG_BOOTMODE_PAD,
-	MX28_PAD_LCD_D03__GPIO_1_3 | MUX_CONFIG_BOOTMODE_PAD,
-	MX28_PAD_LCD_D04__GPIO_1_4 | MUX_CONFIG_BOOTMODE_PAD,
-	MX28_PAD_LCD_D05__GPIO_1_5 | MUX_CONFIG_BOOTMODE_PAD,
 #endif
 };
 
@@ -65,10 +58,10 @@ static uint8_t mxs_get_bootmode_index(void)
 	int i;
 	uint8_t masked;
 
+#if defined(CONFIG_MX23)
 	/* Setup IOMUX of bootmode pads to GPIO */
 	mxs_iomux_setup_multiple_pads(iomux_boot, ARRAY_SIZE(iomux_boot));
 
-#if defined(CONFIG_MX23)
 	/* Setup bootmode pins as GPIO input */
 	gpio_direction_input(MX23_PAD_LCD_D00__GPIO_1_0);
 	gpio_direction_input(MX23_PAD_LCD_D01__GPIO_1_1);
@@ -83,21 +76,11 @@ static uint8_t mxs_get_bootmode_index(void)
 	bootmode |= (gpio_get_value(MX23_PAD_LCD_D03__GPIO_1_3) ? 1 : 0) << 3;
 	bootmode |= (gpio_get_value(MX23_PAD_LCD_D05__GPIO_1_5) ? 1 : 0) << 5;
 #elif defined(CONFIG_MX28)
-	/* Setup bootmode pins as GPIO input */
-	gpio_direction_input(MX28_PAD_LCD_D00__GPIO_1_0);
-	gpio_direction_input(MX28_PAD_LCD_D01__GPIO_1_1);
-	gpio_direction_input(MX28_PAD_LCD_D02__GPIO_1_2);
-	gpio_direction_input(MX28_PAD_LCD_D03__GPIO_1_3);
-	gpio_direction_input(MX28_PAD_LCD_D04__GPIO_1_4);
-	gpio_direction_input(MX28_PAD_LCD_D05__GPIO_1_5);
-
-	/* Read bootmode pads */
-	bootmode |= (gpio_get_value(MX28_PAD_LCD_D00__GPIO_1_0) ? 1 : 0) << 0;
-	bootmode |= (gpio_get_value(MX28_PAD_LCD_D01__GPIO_1_1) ? 1 : 0) << 1;
-	bootmode |= (gpio_get_value(MX28_PAD_LCD_D02__GPIO_1_2) ? 1 : 0) << 2;
-	bootmode |= (gpio_get_value(MX28_PAD_LCD_D03__GPIO_1_3) ? 1 : 0) << 3;
-	bootmode |= (gpio_get_value(MX28_PAD_LCD_D04__GPIO_1_4) ? 1 : 0) << 4;
-	bootmode |= (gpio_get_value(MX28_PAD_LCD_D05__GPIO_1_5) ? 1 : 0) << 5;
+	/* The global boot mode will be detected by ROM code and its value
+	 * is stored@the fixed address 0x00019BF0 in OCRAM.
+	 */
+#define GLOBAL_BOOT_MODE_ADDR 0x00019BF0
+	bootmode = __raw_readl(GLOBAL_BOOT_MODE_ADDR);
 #endif
 
 	for (i = 0; i < ARRAY_SIZE(mxs_boot_modes); i++) {
-- 
2.3.4

[U-Boot] [PATCH 1/1] ARM: mxs: Get boot mode from OCRAM

[Stefano Babic]

On 26/03/2015 23:53, J?rg Krause wrote:
> Reading the boot mode pins after power-up does not necessarily represent the
> boot mode used by the ROM loader. For example the state of a pin may have
> changed because a recovery switch which was pressed to enter USB mode is
> already released after plugging in USB.
> 
> The ROM loader stores the value a fixed address in OCRAM. Use this value
> instead of reading the boot map pins.
> 
> The GLOBAL_BOOT_MODE_ADDR for i.MX28 is taken from an U-Boot patch for the
> MX28EVK:
> http://repository.timesys.com/buildsources/u/u-boot/u-boot-2009.08/u-boot-2009.08-mx28-201012211513.patch
> 
> Leave the boot mode detection for the i.MX23 untouched. Someone has to test
> whether the i.MX ROM loader does also store the boot mode in OCRAM and if the
> address match.
> 
> This patch superseeds my incorrect patch:
> ARM: mxs: get boot mode from OTP
> http://patchwork.ozlabs.org/patch/454930/
> 
> Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>
> Cc: Stefano Babic <sbabic@denx.de>
> ---

Applied to u-boot-imx, thanks !

Best regards,
Stefano Babic

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[U-Boot] [PATCH 1/1] ARM: mxs: Get boot mode from OCRAM

[Robert Deliën]

> The GLOBAL_BOOT_MODE_ADDR for i.MX28 is taken from an U-Boot patch for the
> MX28EVK:
> http://repository.timesys.com/buildsources/u/u-boot/u-boot-2009.08/u-boot-2009.08-mx28-201012211513.patch

It could be 0x0001a7f0 too:
/* The global boot mode will be detected by ROM code and
 * a boot mode value will be stored at fixed address:
 * TO1.0 addr 0x0001a7f0
 * TO1.2 addr 0x00019BF0
 */
#ifndef MX28_EVK_TO1_0
 #define GLOBAL_BOOT_MODE_ADDR 0x00019BF0
#else
 #define GLOBAL_BOOT_MODE_ADDR 0x0001a7f0
#endif
Probably depending on the silicon spin, so perhaps we want to make a CONFIG_ for older silicon.

And the numbers read at this address don't match the numbers read from the boot mode GPIO pin. Only the lowest 4 bits represent the actual boot device and below the definitions:
#define BOOT_MODE_USB0                  0x0
#define BOOT_MODE_I2C0                  0x1
#define BOOT_MODE_SPI2                  0x2
#define BOOT_MODE_SPI3                  0x3
#define BOOT_MODE_GPMI                  0x4
#define BOOT_MODE_rsvd1                 0x5
#define BOOT_MODE_JTAG                  0x6
#define BOOT_MODE_rsvd3                 0x7
#define BOOT_MODE_SPI3_EE               0x8
#define BOOT_MODE_SSP0                  0x9
#define BOOT_MODE_SSP1                  0xa
#define BOOT_MODE_rsvd4                 0xb
#define BOOT_MODE_rsvd5                 0xc
#define BOOT_MODE_rsvd6                 0xd
#define BOOT_MODE_rsvd7                 0xe
#define BOOT_MODE_TEST                  0xf
Higher bits have other purposes. On my board, for example, a value of 0x14 is reported when booting from NAND flash.

Having said all of this, I think your way is definitely the way to go.