Bootloader: Difference between revisions

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Boot9 can also boot from non-NAND. For this a different set of RSA pubks are used(separate pubks for retail/devunit like NAND). The spiflash FIRM image for this is also encrypted with AES-CBC using a normalkey stored in prot_boot9(separate for retail/devunit). This encryption is basically used instead of what is used for NAND-firm-partitions. This encryption is only used for the FIRM sections, the FIRM header is used raw. The AES keyslot for this is only overwritten afterwards when booting from non-NAND fails. AES keyslot 0x3F is used for this.

CTR_word[0] = firmimageoffset;

CTR_word[0] = firmimageoffset;//FIRM section offset from FIRM header

CTR_word[1] = outbufaddr;

CTR_word[1] = outbufaddr;//FIRM section load addr

CTR_word[2] = readsize;

CTR_word[2] = readsize;//FIRM section size

CTR_word[3] = readsize;

CTR_word[3] = readsize;//FIRM section size

When booting from NAND fails, boot9 will then attempt to boot from Wifi SPI-flash(this only triggers when the wifi module hw is properly accessible/connected, which is normally the case). The base offset for spiflash FIRM is 0x400. Note that this region is write-protected by the spiflash.

@@ Line 14: / Line 14: @@
 Boot9 can also boot from non-NAND. For this a different set of RSA pubks are used(separate pubks for retail/devunit like NAND). The spiflash FIRM image for this is also encrypted with AES-CBC using a normalkey stored in prot_boot9(separate for retail/devunit). This encryption is basically used instead of what is used for NAND-firm-partitions. This encryption is only used for the FIRM sections, the FIRM header is used raw. The AES keyslot for this is only overwritten afterwards when booting from non-NAND fails. AES keyslot 0x3F is used for this.
-   CTR_word[0] = firmimageoffset;
+   CTR_word[0] = firmimageoffset;//FIRM section offset from FIRM header
-   CTR_word[1] = outbufaddr;
+   CTR_word[1] = outbufaddr;//FIRM section load addr
-   CTR_word[2] = readsize;
+   CTR_word[2] = readsize;//FIRM section size
-   CTR_word[3] = readsize;
+   CTR_word[3] = readsize;//FIRM section size
 When booting from NAND fails, boot9 will then attempt to boot from Wifi SPI-flash(this only triggers when the wifi module hw is properly accessible/connected, which is normally the case). The base offset for spiflash FIRM is 0x400. Note that this region is write-protected by the spiflash.