From 647ba68841dbb5de82983a1cad4cf42bcf63b9b3 Mon Sep 17 00:00:00 2001 From: Neil Armstrong Date: Wed, 6 Jul 2022 11:36:49 +0200 Subject: [PATCH 1/2] doc: board: amlogic: add documentation on boot flow This is a preliminary documentation introducing different boot sequences, and notably the recovery mode. Signed-off-by: Neil Armstrong Reviewed-by: Mattijs Korpershoek Reviewed-by: Simon Glass Link: https://lore.kernel.org/r/20220706093649.3261229-1-narmstrong@baylibre.com --- doc/board/amlogic/boot-flow.rst | 134 ++++++++++++++++++++++++++++++++ doc/board/amlogic/index.rst | 1 + 2 files changed, 135 insertions(+) create mode 100644 doc/board/amlogic/boot-flow.rst diff --git a/doc/board/amlogic/boot-flow.rst b/doc/board/amlogic/boot-flow.rst new file mode 100644 index 00000000000..2049672b1bd --- /dev/null +++ b/doc/board/amlogic/boot-flow.rst @@ -0,0 +1,134 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +Amlogic SoC Boot Flow +===================== + +The Amlogic SoCs have a pre-defined boot sequence in the SoC ROM code. Here are +the possible boot sources of different SoC families supported by U-Boot: + +GX* & AXG family +---------------- + ++----------+--------------------+-------+-------+---------------+---------------+ +| | 1 | 2 | 3 | 4 | 5 | ++==========+====================+=======+=======+===============+===============+ +| S905 | POC=0: SPI NOR | eMMC | NAND | SD Card | USB Device | +| S905X | | | | | | +| S905L | | | | | | +| S905W | | | | | | +| S912 | | | | | | ++----------+--------------------+-------+-------+---------------+---------------+ +| S805X | POC=0: SPI NOR | eMMC | NAND | USB Device | - | +| A113D | | | | | | +| A113X | | | | | | ++----------+--------------------+-------+-------+---------------+---------------+ + +POC pin: `NAND_CLE` + +Some boards provide a button to force USB BOOT which disables the eMMC clock signal +to bypass the eMMC stage. Others have removable eMMC modules; removing the eMMC and +SDCard will allow boot from USB. + +An exception is the lafrite board (aml-s805x-xx) which has no SDCard slot and boots +from SPI. The only ways to boot the lafrite board from USB are: + + - Erase the first sectors of SPI NOR flash + - Insert an HDMI boot plug forcing boot over USB + +The VIM1 and initial VIM2 boards provide a test point on the eMMC signals to block +the storage from answering and continue to the next boot step. + +The USB Device boot uses the first USB interface. On some boards this port is only +available on an USB-A type connector and needs an special Type-A to Type-A cable to +communicate with the BootROM. + +G12* & SM1 family +----------------- + ++-------+-------+-------+---------------+---------------+---------------+---------------+ +| POC0 | POC1 | POC2 | 1 | 2 | 3 | 4 | ++=======+=======+=======+===============+===============+===============+===============+ +| 0 | 0 | 0 | USB Device | SPI NOR | NAND/eMMC | SDCard | ++-------+-------+-------+---------------+---------------+---------------+---------------+ +| 0 | 0 | 1 | USB Device | NAND/eMMC | SDCard | - | ++-------+-------+-------+---------------+---------------+---------------+---------------+ +| 0 | 1 | 0 | SPI NOR | NAND/eMMC | SDCard | USB Device | ++-------+-------+-------+---------------+---------------+---------------+---------------+ +| 0 | 1 | 1 | SPI NAND | NAND/eMMC | USB Device | - | ++-------+-------+-------+---------------+---------------+---------------+---------------+ +| 1 | 0 | 0 | USB Device | SPI NOR | NAND/eMMC | SDCard | ++-------+-------+-------+---------------+---------------+---------------+---------------+ +| 1 | 0 | 1 | USB Device | NAND/eMMC | SDCard | - | ++-------+-------+-------+---------------+---------------+---------------+---------------+ +| 1 | 1 | 0 | SPI NOR | NAND/eMMC | SDCard | USB Device | ++-------+-------+-------+---------------+---------------+---------------+---------------+ +| 1 | 1 | 1 | NAND/eMMC | SDCard | USB Device | - | ++-------+-------+-------+---------------+---------------+---------------+---------------+ + +The last option (1/1/1) is the normal default seen on production devices. + + * POC0 pin: `BOOT_4` (0 and all other 1 means SPI NAND boot first) + * POC1 pin: `BOOT_5` (0 and all other 1 means USB Device boot first + * POC2 pin: `BOOT_6` (0 and all other 1 means SPI NOR boot first) + +Most boards provide a button to force USB BOOT which lowers `BOOT_5` to 0. Some boards +provide a test point on the eMMC or SPI NOR clock signals to block the storage from +answering and continue to the next boot step. + +The Khadas VIM3/3L boards embed a microcontroller which sets POC signals according +to its configuration or a specific key press sequence to either boot from SPI NOR +or eMMC then SDCard, or boot as an USB Device. + +The Odroid N2/N2+ has a hardware switch to select between SPI NOR or eMMC boot. + +Boot Modes +---------- + + * SDCard + +The BootROM fetches the first SDCard sectors in one sequence, then checks the content +of the data. The BootROM expects to find the FIP binary in sector 1, 512 bytes offset +from the start. + + * eMMC + +The BootROM fetches the first sectors in one sequence, first on the main partition, +and then on the Boot0 followed by Boot1 HW partitions. After each read, the BootROM +checks the data and looks to the next partition if it fails. The BootROM expects to +find the FIP binary in sector 1, 512 bytes offset from the start. + + * SPI NOR + +The BootROM fetches the first SPI NOR sectors in one sequence, then checks the content +of the data. The BootROM expects to find the FIP binary in sector 1, 512 bytes offset +from the start. + + * NAND & SPI NAND + +These modes are rarely used in open platforms and no details are available. + + * USB Device + +The BootROM sets the USB Gadget interface to serve a custom USB protocol with the +USB ID 1b8e:c003. The Amlogic `update` utility is designed to use this protocol. It +is also implemented in the Amlogic Vendor U-Boot. + +The open-source `pyamlboot` utility https://github.com/superna9999/pyamlboot also +implements this protocol and can load U-Boot in memory in order to start the SoC +without any attached storage or to recover from a failed/incorrect image flash. + +HDMI Recovery +------------- + +The BootROM also briefly reads 8 bytes at address I2C 0x52 offset 0xf8 (248) on the +HDMI DDC bus. If the content is `boot@USB` it will force USB boot mode. If the content +is `boot@SDC` it will force SDCard boot mode. + +If USB Device doesn't enumerate or SD Card boot step doesn't work, the BootROM will +continue with the normal boot sequence. + +Special boot dongles can be built by connecting a 256bytes EEPROM set to answer on +address 0x52, and program `boot@USB` or `boot@SDC` at offset 0xf8 (248). + +Note: If the SoC is booted with USB Device forced at first step, it will keep the boot +order on warm reboot. Only cold reboot (power removed) will reset the boot order. diff --git a/doc/board/amlogic/index.rst b/doc/board/amlogic/index.rst index 9c7fadf2c02..8b9f1e2e1d8 100644 --- a/doc/board/amlogic/index.rst +++ b/doc/board/amlogic/index.rst @@ -81,6 +81,7 @@ Boot Documentation :maxdepth: 1 pre-generated-fip + boot-flow Board Documentation ------------------- From 3145e0d0ff0837647351f2ca261b4cde779f83e0 Mon Sep 17 00:00:00 2001 From: Jerome Brunet Date: Thu, 4 Aug 2022 16:41:38 +0200 Subject: [PATCH 2/2] ARM: meson: fixup error on efuse commands return All `sm efuseread/efusewrite` commands exit with an error, even if the fuse have actually been dealt with correctly. This is because the smc call return the size it actually processed but this result is checked against 0. Return failure in do_efuse_read/write if the return value of meson_sm_read/write_efuse() is not the requested size. Fixes: 52195ba5f579 ("ARM: amlogic: add sm efuse write support and cmd for read/write efuse") Signed-off-by: Jerome Brunet Reviewed-by: Neil Armstrong Signed-off-by: Neil Armstrong Link: https://lore.kernel.org/r/20220804144138.33809-1-jbrunet@baylibre.com --- arch/arm/mach-meson/sm.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-meson/sm.c b/arch/arm/mach-meson/sm.c index 6c28c0f5e44..d6eb910689f 100644 --- a/arch/arm/mach-meson/sm.c +++ b/arch/arm/mach-meson/sm.c @@ -82,10 +82,7 @@ ssize_t meson_sm_write_efuse(uintptr_t offset, void *buffer, size_t size) smc_call(®s); - if (regs.regs[0] == 0) - return -1; - - return 0; + return regs.regs[0]; } #define SM_CHIP_ID_LENGTH 119 @@ -222,7 +219,7 @@ static int do_efuse_read(struct cmd_tbl *cmdtp, int flag, int argc, address = simple_strtoul(argv[3], NULL, 0); ret = meson_sm_read_efuse(offset, (void *)address, size); - if (ret) + if (ret != size) return CMD_RET_FAILURE; return CMD_RET_SUCCESS; @@ -243,7 +240,7 @@ static int do_efuse_write(struct cmd_tbl *cmdtp, int flag, int argc, address = simple_strtoul(argv[3], NULL, 0); ret = meson_sm_write_efuse(offset, (void *)address, size); - if (ret) + if (ret != size) return CMD_RET_FAILURE; return CMD_RET_SUCCESS;