On Mon, 10 Aug 2009, Peter Tyser wrote:
On Mon, 2009-08-10 at 15:27 -0400, Jerry Van Baren wrote:
Kumar Gala wrote:
On Aug 10, 2009, at 1:59 PM, Zang Roy-R61911 wrote:
-----Original Message----- From: Kumar Gala [mailto:galak@kernel.crashing.org] Sent: Monday, August 10, 2009 13:41 PM To: Wolfgang Denk Cc: U-Boot-Users ML; Zang Roy-R61911 Subject: Re: 85xx: MPC8536DS board does not build
On Aug 10, 2009, at 1:22 PM, Wolfgang Denk wrote:
Dear Kumar Gala,
In message <0EB7516A-2F14-42F7- A6ED-555ADFAB3105@kernel.crashing.org> you wrote: >> Allocate more space for U-Boot? > I might turn of BEDBUG as its never been properly enabled on > e500/85xx > platforms. Is there any problem with the bigger image which I don't
understand
yet? Normally we just move down the TEXT_BASE by a sector,
and that's
it.
Not specifically, its just that ever 85xx image to date has been 512k. I'm just trying to avoid this being the first one that changes that historic fact. Especially since compilers like gcc-4.3 seem
to
be able to fit the size in 512k.
We may have more requirements to support graphic in u-boot. Sooner and later, the size will exceed 512K. Should we have some
plan
for this?
So if we are going to increase the limit from 512k do we go to 768k
or
1M? (Sector size on the board appears to 128k)
I would also like to know how big the flashes are on some of the
other
85xx boards that u-boot supports.
- k
Hi Kumar, Roy,
512K is pretty big for u-boot (not unheard of, but still...). Is it really 512K or is it using a full page to hold the boot page (top 4K
of
memory) and one page for the env (unavoidable):
+--------------------------------------------------------
0x1_0000_0000
| One sector dedicated for the power up page (only using 4K) +--------------------------------------------------------
0x0_F800_0000
| One sector dedicated for the env +--------------------------------------------------------
0x0_F000_0000
| Two sectors of u-boot +----
0x0_E800_0000
| +--------------------------------------------------------
0x0_E000_0000
If that is the case, you can gain a sector (less 4K) by rearranging
your
memory map: +--------------------------------------------------------
0x1_0000_0000
| One page (4K) of power up vector, the rest is u-boot +----
0x0_F800_0000
| +----
0x0_F000_0000
| Three sectors (less 4K) of u-boot +--------------------------------------------------------
0x0_E800_0000
| One sector dedicated for the env +--------------------------------------------------------
0x0_E000_0000
This also makes reprogramming u-boot nicer because your power up
vector
and u-boot itself are contiguous.
Hi Jerry, Currently a sector shouldn't be wasted just for the 4K boot page. Your second diagram above is similar to current operation - a chunk of the 4k bootpage is wasted/unused, but other u-boot code shares the same flash sector with the 4K boot page. So a little space may be wasted, but not too much (ie less than 4K).
That is where top boot block flashes come handy... It is not just that 128K sector is a huge waste for 4K boot block, the same is true for environment...
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