changeset 19:2d9c927cc24b

boot ROM re: some better comments
author Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
date Thu, 25 Apr 2013 06:03:27 +0000
parents 123cb5021b64
children a52e76c12e6b
files bootrom.disasm
diffstat 1 files changed, 8 insertions(+), 2 deletions(-) [+]
line wrap: on
line diff
--- a/bootrom.disasm	Thu Apr 25 05:47:59 2013 +0000
+++ b/bootrom.disasm	Thu Apr 25 06:03:27 2013 +0000
@@ -148,6 +148,7 @@
      1b8:	eb000451 	bl	0x1304
      1bc:	e8bd8000 	ldmia	sp!, {pc}
 case 7:
+; apparently never exercised
      1c0:	e3a0c061 	mov	r12, #97	; 0x61 'a'
      1c4:	e5c0c001 	strb	r12, [r0, #1]
      1c8:	e3a01002 	mov	r1, #2	; 0x2
@@ -1814,6 +1815,9 @@
 ; If the argument in R0 equals 1, a call to the 0xe2c memmap/clock init
 ; function is made first, with the same arguments as at the beginning
 ; of main().
+;
+; Note that this routine is not called from anywhere in the boot ROM
+; itself - but its address is listed in the CAL228 document.
 
     1608:	e92d4000 	stmdb	sp!, {lr}
     160c:	e24dd008 	sub	sp, sp, #8	; 0x8
@@ -2074,5 +2078,7 @@
     1ff0:	e51ff024 	ldr	pc, [pc, #-36]	; 0x1fd4
     1ff4:	e51ff024 	ldr	pc, [pc, #-36]	; 0x1fd8
     1ff8:	e51ff024 	ldr	pc, [pc, #-36]	; 0x1fdc
-; ???
-    1ffc:	03000000 	tsteq	r0, #0	; 0x0
+; CAL228 document identifies the last 16-bit word as the version number
+; The version we've got appears to be a perfect match for what that
+; document describes.
+    1ffc:	03000000