Add an entry point when signing Arm images #163
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Reads the entry point and stack pointer from the vector table Assumes vector table is at 0x10000000 unless a vector_table metadata item is present
main.cpp
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| std::shared_ptr<entry_point_item> entry_point = new_block.get_item<entry_point_item>(); | ||
| if (entry_point == nullptr) { | ||
| std::shared_ptr<vector_table_item> vtor = new_block.get_item<vector_table_item>(); | ||
| uint32_t vtor_loc = 0x10000000; |
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should come from wherever the start of the image is; which in flash binaries is affected by roll; and would be in RAM for RAM binaries (where i guess it must be at 0x20000000 in these cases)
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Fixed - I've added support for adding the rolling window delta to the VTOR location, and it checks if the ELF entry point is in SRAM and reads the VTOR from there if that's the case
| std::shared_ptr<entry_point_item> entry_point = new_block.get_item<entry_point_item>(); | ||
| if (entry_point == nullptr) { | ||
| std::shared_ptr<vector_table_item> vtor = new_block.get_item<vector_table_item>(); | ||
| uint32_t vtor_loc = elf->header().entry < SRAM_START ? 0x10000000 : 0x20000000; |
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do we need to check for XIP_SRAM-only binaries here? I forget if they can be signed (i believe so)
| @@ -4630,6 +4658,27 @@ vector<uint8_t> sign_guts_bin(iostream_memory_access in, private_t private_key, | |||
| new_block.items.push_back(version); | |||
| } | |||
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| // Add entry point when signing Arm images | |||
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Hmm; i hadn't really considered the BIN case where we don't know where the user is planning to load it. Perhaps we don't do all this and just give a warning instead? (or allow a "target address" option) - i'd be happy with the former for now, we can always add the new option later if it is useful
| new_block.items.push_back(entry_point); | ||
| } | ||
| } | ||
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| hash_andor_sign( |
Reads the entry point and stack pointer from the vector table, and adds them to the image_def as a new entry_point item. This is only done for signing Arm executable images.
This assumes that the vector table is at 0x10000000 unless a vector_table metadata item is present, which the SDK adds for no_flash binaries, so it should work with all SDK binaries.