From 33cb4cfe9d5e12eaf4a06e1ef88d0734e12eb742 Mon Sep 17 00:00:00 2001 From: Marco Casaroli Date: Tue, 11 Aug 2026 11:13:02 +0200 Subject: [PATCH] xtensa/esp32: Let a protected build boot from simple boot. A protected build on the ESP32 could only use the legacy IDF image format. Kconfig allowed simple boot to be selected with BUILD_PROTECTED, because the legacy format is only a default and not a select, but the result did not link and then did not boot. Simple boot has no second-stage bootloader. __start() maps the flash itself, so everything it reaches must already be in RAM. kernel-space.ld pinned none of it, and it did not place esp32_start at all, so the entry point went to the flash the code was about to map. The chip loaded the RAM segments, jumped to 0x400d0ba4 and took an IllegalInstruction on the first instruction. So this pins the bootloader, flash, ROM, clock and log objects that bootloader_init() and map_rom_segments() reach, along with esp32_start itself, and defines the six _image_* symbols that __start() needs. All of it is behind CONFIG_ESPRESSIF_SIMPLE_BOOT, so a legacy build gets the same IRAM it had before. kernel-space.ld also had no `#include '. It held no conditionals until now, so nothing showed the omission: the new blocks compiled away silently and the link failed as if the file had not been changed. The default is unchanged. A protected build still selects the legacy format unless the user clears CONFIG_ESP32_APP_FORMAT_LEGACY. Verified on an ESP32-DevKitC V4, ESP32-D0WD-V3 revision 3.1, with esp32-devkitc:knsh and the legacy format turned off. The kernel flashes at 0x1000 and the user image at 0x90000, with no bootloader and no partition table. It maps seven segments, reaches NSH, and runs ostest to the same point as the legacy build. Assisted-by: Claude Opus 5 (1M context) Signed-off-by: Marco Casaroli --- .../esp32/common/scripts/kernel-space.ld | 159 ++++++++++++++++++ 1 file changed, 159 insertions(+) diff --git a/boards/xtensa/esp32/common/scripts/kernel-space.ld b/boards/xtensa/esp32/common/scripts/kernel-space.ld index 4a98e369ce3e4..940f90f80bd32 100644 --- a/boards/xtensa/esp32/common/scripts/kernel-space.ld +++ b/boards/xtensa/esp32/common/scripts/kernel-space.ld @@ -20,6 +20,8 @@ * ****************************************************************************/ +#include + /* Provide these so there is no need for using config files for this */ __uirom_start = ORIGIN(UIROM); @@ -159,6 +161,85 @@ SECTIONS *libkarch.a:interrupt.*(.literal.intr_get_item .text.intr_get_item) *libkarch.a:interrupt.*(.literal.intr_handler_get_arg .text.intr_handler_get_arg) +#ifdef CONFIG_ESPRESSIF_SIMPLE_BOOT + /* Simple boot has no second-stage bootloader. __start() runs + * bootloader_init() and map_rom_segments() before any flash mapping + * exists, so everything they reach must be resident in RAM. + */ + + /* __start() itself runs before the mapping it creates, so it cannot + * live in the flash it is about to map. + */ + + esp32_start.*(.literal .text .literal.* .text.*) + + *libkarch.a:*esp_loader.*(.literal .text .literal.* .text.*) + *libkarch.a:*bootloader_init.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_common.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_common_loader.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_console.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_console_loader.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_banner_wrap.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_clock_init.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_clock_loader.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_efuse.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_esp32.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_flash.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_flash_config_esp32.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_mem.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_panic.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_random.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_random_esp32.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_sha.*(.text .text.* .literal .literal.*) + *libkarch.a:*bootloader_soc.*(.text .text.* .literal .literal.*) + *libkarch.a:*esp_image_format.*(.text .text.* .literal .literal.*) + *libkarch.a:*flash_encrypt.*(.text .text.* .literal .literal.*) + *libkarch.a:*flash_qio_mode.*(.text .text.* .literal .literal.*) + *libkarch.a:*brownout_hal.*(.text .text.* .literal .literal.*) + *libkarch.a:*cpu.*(.text .text.* .literal .literal.*) + *libkarch.a:*cpu_region_protect.*(.text .text.* .literal .literal.*) + *libkarch.a:*gpio_hal.*(.text .text.* .literal .literal.*) + *libkarch.a:*periph_ctrl.*(.text .text.* .literal .literal.*) + *libkarch.a:*clk.*(.text .text.* .literal .literal.*) + *libkarch.a:*clk_tree_hal.*(.text .text.* .literal .literal.*) + *libkarch.a:*esp_clk_tree.*(.text .text.* .literal .literal.*) + *libkarch.a:*esp_clk_tree_common.*(.text .text.* .literal .literal.*) + *libkarch.a:*rtc_init.*(.text .text.* .literal .literal.*) + *libkarch.a:*rtc_clk.*(.text .text.* .literal .literal.*) + *libkarch.a:*rtc_clk_init.*(.text .text.* .literal .literal.*) + *libkarch.a:*rtc_sleep.*(.text .text.* .literal .literal.*) + *libkarch.a:*rtc_time.*(.text .text.* .literal .literal.*) + *libkarch.a:*regi2c_ctrl.*(.text .text.* .literal .literal.*) + *libkarch.a:*efuse_hal.*(.text .text.* .literal .literal.*) + *libkarch.a:*efuse_utility.*(.text .text.* .literal .literal.*) + *libkarch.a:*mmu_hal.*(.text .text.* .literal .literal.*) + *libkarch.a:*mpu_hal.*(.text .text.* .literal .literal.*) + *libkarch.a:*cache_esp32.*(.text .text.* .literal .literal.*) + *libkarch.a:*cache_hal_esp32.*(.text .text.* .literal .literal.*) + *libkarch.a:*uart_hal.*(.text .text.* .literal .literal.*) + *libkarch.a:*uart_hal_iram.*(.text .text.* .literal .literal.*) + *libkarch.a:*uart_periph.*(.text .text.* .literal .literal.*) + *libkarch.a:*wdt_hal_iram.*(.text .text.* .literal .literal.*) + *libkarch.a:*esp_rom_uart.*(.text .text.* .literal .literal.*) + *libkarch.a:*esp_rom_sys.*(.text .text.* .literal .literal.*) + *libkarch.a:*esp_rom_spiflash.*(.text .text.* .literal .literal.*) + *libkarch.a:*esp_rom_wdt.*(.text .text.* .literal .literal.*) + *libkarch.a:*log.*(.text .text.* .literal .literal.*) + *libkarch.a:*log_lock.*(.literal .literal.* .text .text.*) + *libkarch.a:*log_print.*(.literal .literal.* .text .text.*) + *libkarch.a:*log_timestamp.*(.literal .literal.* .text .text.*) + *libkarch.a:*log_timestamp_common.*(.literal .literal.* .text .text.*) + *libkarch.a:*log_write.*(.literal .literal.* .text .text.*) + *libkarch.a:esp_app_desc.*(.literal .literal.* .text .text.*) + *libkarch.a:esp_flash_api.*(.text .text.* .literal .literal.*) + *libkarch.a:esp_flash_spi_init.*(.text .text.* .literal .literal.*) + *libkarch.a:spi_flash_hal_gpspi.*(.literal .literal.* .text .text.*) + *libkarch.a:spi_flash_encrypt_hal_iram.*(.text .text.* .literal .literal.*) + *libkarch.a:spi_flash_os_func_noos.*(.literal .literal.* .text .text.*) + *libkarch.a:spi_flash_os_func_app.*(.literal .literal.* .text .text.*) + *libkarch.a:spi_flash_wrap.*(.literal .literal.* .text .text.*) +#endif + *(.wifirxiram .wifirxiram.*) *(.wifi0iram .wifi0iram.*) *(.wifislpiram .wifislpiram.*) @@ -270,6 +351,67 @@ SECTIONS *libkarch.a:os.*(.rodata.g_int_flags_count .rodata.g_int_flags) *libkc.a:arch_atomic.*(.rodata .rodata.*) +#ifdef CONFIG_ESPRESSIF_SIMPLE_BOOT + /* The read-only data of everything pinned into IRAM above. */ + + esp32_start.*(.rodata .rodata.*) + + *libkarch.a:*esp_loader.*(.rodata .rodata.*) + *libkarch.a:*bootloader_init.*(.rodata .rodata.*) + *libkarch.a:*bootloader_common.*(.rodata .rodata.*) + *libkarch.a:*bootloader_common_loader.*(.rodata .rodata.*) + *libkarch.a:*bootloader_console.*(.rodata .rodata.*) + *libkarch.a:*bootloader_console_loader.*(.rodata .rodata.*) + *libkarch.a:*bootloader_banner_wrap.*(.rodata .rodata.*) + *libkarch.a:*bootloader_clock_init.*(.rodata .rodata.*) + *libkarch.a:*bootloader_clock_loader.*(.rodata .rodata.*) + *libkarch.a:*bootloader_efuse.*(.rodata .rodata.*) + *libkarch.a:*bootloader_esp32.*(.rodata .rodata.*) + *libkarch.a:*bootloader_flash.*(.rodata .rodata.*) + *libkarch.a:*bootloader_flash_config_esp32.*(.rodata .rodata.*) + *libkarch.a:*bootloader_mem.*(.rodata .rodata.*) + *libkarch.a:*bootloader_panic.*(.rodata .rodata.*) + *libkarch.a:*bootloader_random.*(.rodata .rodata.*) + *libkarch.a:*bootloader_random_esp32.*(.rodata .rodata.*) + *libkarch.a:*bootloader_sha.*(.rodata .rodata.*) + *libkarch.a:*bootloader_soc.*(.rodata .rodata.*) + *libkarch.a:*esp_image_format.*(.rodata .rodata.*) + *libkarch.a:*flash_encrypt.*(.rodata .rodata.*) + *libkarch.a:*flash_qio_mode.*(.rodata .rodata.*) + *libkarch.a:*brownout_hal.*(.rodata .rodata.*) + *libkarch.a:*cpu.*(.rodata .rodata.*) + *libkarch.a:*cpu_region_protect.*(.rodata .rodata.*) + *libkarch.a:*gpio_hal.*(.rodata .rodata.*) + *libkarch.a:*periph_ctrl.*(.rodata .rodata.*) + *libkarch.a:*clk.*(.rodata .rodata.*) + *libkarch.a:*clk_tree_hal.*(.rodata .rodata.*) + *libkarch.a:*esp_clk_tree.*(.rodata .rodata.*) + *libkarch.a:*esp_clk_tree_common.*(.rodata .rodata.*) + *libkarch.a:*rtc_init.*(.rodata .rodata.*) + *libkarch.a:*rtc_clk.*(.rodata .rodata.*) + *libkarch.a:*rtc_clk_init.*(.rodata .rodata.*) + *libkarch.a:*rtc_time.*(.rodata .rodata.*) + *libkarch.a:*regi2c_ctrl.*(.rodata .rodata.*) + *libkarch.a:*efuse_hal.*(.rodata .rodata.*) + *libkarch.a:*efuse_utility.*(.rodata .rodata.*) + *libkarch.a:*mmu_hal.*(.rodata .rodata.*) + *libkarch.a:*mpu_hal.*(.rodata .rodata.*) + *libkarch.a:*cache_esp32.*(.rodata .rodata.*) + *libkarch.a:*cache_hal_esp32.*(.rodata .rodata.*) + *libkarch.a:*uart_hal.*(.rodata .rodata.*) + *libkarch.a:*uart_hal_iram.*(.rodata .rodata.*) + *libkarch.a:*uart_periph.*(.rodata .rodata.*) + *libkarch.a:*wdt_hal_iram.*(.rodata .rodata.*) + *libkarch.a:*esp_rom_uart.*(.rodata .rodata.*) + *libkarch.a:*esp_rom_sys.*(.rodata .rodata.*) + *libkarch.a:*esp_rom_spiflash.*(.rodata .rodata.*) + *libkarch.a:*esp_rom_wdt.*(.rodata .rodata.*) + *libkarch.a:*log.*(.rodata .rodata.*) + *libkarch.a:esp_app_desc.*(.rodata .rodata.*) + *libkarch.a:esp_flash_api.*(.rodata .rodata.*) + *libkarch.a:esp_flash_spi_init.*(.rodata .rodata.*) +#endif + *libsched.a:sched_suspendscheduler.*(.rodata .rodata.*) *libsched.a:sched_thistask.*(.rodata .rodata.*) *libsched.a:sched_note.*(.rodata .rodata.*) @@ -367,6 +509,23 @@ SECTIONS _etext = .; } >KIROM +#ifdef CONFIG_ESPRESSIF_SIMPLE_BOOT + /* Simple boot has no second-stage bootloader to map the flash, so __start() + * does it. map_rom_segments() reads the segment table out of the image in + * flash, but the entry point still needs these to be defined. + */ + + _image_irom_vma = ADDR(.flash.text); + _image_irom_lma = LOADADDR(.flash.text); + _image_irom_size = LOADADDR(.flash.text) + SIZEOF(.flash.text) - + _image_irom_lma; + + _image_drom_vma = ADDR(.flash.rodata); + _image_drom_lma = LOADADDR(.flash.rodata); + _image_drom_size = LOADADDR(.flash.rodata) + SIZEOF(.flash.rodata) - + _image_drom_lma; +#endif + .rtc.text : { . = ALIGN(4);