linker script: Add some comments about significance of 0x18 byte offset

This commit is contained in:
Angus Gratton 2017-07-19 17:38:05 +10:00 committed by Angus Gratton
parent c230e4280c
commit 2d9770fd00

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@ -25,9 +25,17 @@ MEMORY
/* IRAM for PRO cpu. Not sure if happy with this, this is MMU area... */
iram0_0_seg (RX) : org = 0x40080000, len = 0x20000
/* Even though the segment name is iram, it is actually mapped to flash */
/* Even though the segment name is iram, it is actually mapped to flash
*/
iram0_2_seg (RX) : org = 0x400D0018, len = 0x330000-0x18
/*
(0x18 offset above is a convenience for the app binary image generation. Flash cache has 64KB pages. The .bin file
which is flashed to the chip has a 0x18 byte file header. Setting this offset makes it simple to meet the flash
cache MMU's constraint that (paddr % 64KB == vaddr % 64KB).)
*/
/* Shared data RAM, excluding memory reserved for ROM bss/data/stack.
Enabling Bluetooth & Trace Memory features in menuconfig will decrease
@ -39,6 +47,8 @@ MEMORY
/* Flash mapped constant data */
drom0_0_seg (R) : org = 0x3F400018, len = 0x400000-0x18
/* (See iram0_2_seg for meaning of 0x18 offset in the above.) */
/* RTC fast memory (executable). Persists over deep sleep.
*/
rtc_iram_seg(RWX) : org = 0x400C0000, len = 0x2000