Remove SPIUnlock from linker script symbols

Add a comment about why it was removed and where it went.

components/bootloader/src/Makefile

@@ -4,7 +4,7 @@
 #
 
 PROJECT_NAME := bootloader
-COMPONENTS := esptool_py bootloader log
+COMPONENTS := esptool_py bootloader log spi_flash
 
 # The bootloader pseudo-component is also included in this build, for its Kconfig.projbuild to be included.
 #

components/esp32/ld/esp32.rom.ld

@@ -1585,6 +1585,8 @@ PROVIDE ( SPIEraseBlock = 0x40062c4c );
 PROVIDE ( SPIEraseChip = 0x40062c14 );
 PROVIDE ( SPIEraseSector = 0x40062ccc );
 PROVIDE ( spi_flash_attach = 0x40062a6c );
+/* NB: SPIUnlock @ 0x400628b0 has been replaced with an updated
+    version in the "spi_flash" component */
 PROVIDE ( SPILock = 0x400628f0 );
 PROVIDE ( SPIMasterReadModeCnfig = 0x40062b64 );
 PROVIDE ( spi_modes = 0x3ff99270 );
@@ -1596,7 +1598,6 @@ PROVIDE ( SPIReadModeCnfig = 0x40062944 );
 PROVIDE ( SPI_read_status = 0x4006226c );
 /* This is static function, but can be used, not generated by script*/
 PROVIDE ( SPI_read_status_high = 0x40062448 );
-PROVIDE ( SPIUnlock = 0x400628b0 );
 PROVIDE ( SPI_user_command_read = 0x400621b0 );
 PROVIDE ( SPI_flashchip_data = 0x3ffae270 );
 PROVIDE ( SPIWrite = 0x40062d50 );

components/spi_flash/component.mk

@@ -1,3 +1,8 @@
 COMPONENT_ADD_INCLUDEDIRS := include
 
+ifdef IS_BOOTLOADER_BUILD
+# Bootloader needs updated SPIUnlock from this file
+COMPONENT_OBJS := spi_flash_rom_patch.o
+endif
+
 include $(IDF_PATH)/make/component_common.mk