Hello Kumar,
Kumar Gala wrote:
On Sep 5, 2008, at 3:27 AM, Heiko Schocher wrote:
I actually trying to boot a Linux 2.6.27-rc4 Kernel with a Ramdisk and actual u-boot on a MPC82xx based board. And what should I say, it doesnt work anymore :-(
Reason is the following commit:
http://git.denx.de/?p=u-boot.git;a=commitdiff;h=2a1a2cb6e2b87ee550e6f27b647d...
After this commit, u-boot no longer deletes the mem reservation for the initrd in Flash, what stops Linux from booting.
So I did the following, but maybe there is a better way for it?
I don't follow.. can you provide a bit more info about what's going on w/your mem reserves and what locations the ramdisk is at.
OK, I try it ...
We start in lib_ppc/bootm.c (actual u-boot):
147 if (of_size) { 148 /* pass in dummy initrd info, we'll fix up later */ 149 if (fdt_chosen(of_flat_tree, images->rd_start, images->rd_end, 0) < 0) {
This calls fdt_chosen with images->rd_start which are on my Hardware in Flash@0xff21000
fdt_chosen calls
fdt_initrd(of_flat_tree, initrd_start, initrd_end, force);
with initrd = images->rd_start = 0xff210000
fdt initr (): 125 /* 126 * Look for an existing entry and update it. If we don't find 127 * the entry, we will j be the next available slot. 128 */ 129 for (j = 0; j < total; j++) { 130 err = fdt_get_mem_rsv(fdt, j, &addr, &size); 131 if (addr == initrd_start) { 132 fdt_del_mem_rsv(fdt, j); 133 break; 134 } 135 }
didnt find this addres -> didnt call fdt_del_mem_rsv() This is OK here, because its the first call ...
fdt_initrd calls fdt_add_mem_rsv with this value -> One dummy mem reserv for the 0xff210000 value
Ok lets go on, later in lib_ppc/bootm.c:
Here is called fdt_initrd again, now with the values from the initrd somewhere in RAM (which are the right ones) ...
181 #if defined(CONFIG_OF_LIBFDT) 182 /* fixup the initrd now that we know where it should be */ 183 if ((of_flat_tree) && (initrd_start && initrd_end)) 184 fdt_initrd(of_flat_tree, initrd_start, initrd_end, 1); 185 #endif
in fdt initr ():
125 /* 126 * Look for an existing entry and update it. If we don't find 127 * the entry, we will j be the next available slot. 128 */ 129 for (j = 0; j < total; j++) { 130 err = fdt_get_mem_rsv(fdt, j, &addr, &size); 131 if (addr == initrd_start) { 132 fdt_del_mem_rsv(fdt, j); 133 break; 134 } 135 }
didnt find this addresses in RAM -> didnt call fdt_del_mem_rsv() for the dummy reservation (on my Hardware 0xff210000)...
This is NOT OK here!
The code should have been identical to before.
Hmm... seems not so to me ... ... taking a look at your Patch:
Here your Patch for lib_ppc_bootm.c:
#if defined(CONFIG_OF_LIBFDT) /* fixup the initrd now that we know where it should be */ - if ((of_flat_tree) && (initrd_start && initrd_end)) { - uint64_t addr, size; - int total = fdt_num_mem_rsv(of_flat_tree); - int j; - - /* Look for the dummy entry and delete it */ - for (j = 0; j < total; j++) { - fdt_get_mem_rsv(of_flat_tree, j, &addr, &size); - if (addr == images->rd_start) { - fdt_del_mem_rsv(of_flat_tree, j);
This looks for me that the old code explicitly searches for the dummy entry with images->rd_start!!
- break; - } - } - - ret = fdt_add_mem_rsv(of_flat_tree, initrd_start, - initrd_end - initrd_start + 1); - if (ret < 0) { - printf("fdt_chosen: %s\n", fdt_strerror(ret)); - goto error; - } - - do_fixup_by_path_u32(of_flat_tree, "/chosen", - "linux,initrd-start", initrd_start, 0); - do_fixup_by_path_u32(of_flat_tree, "/chosen", - "linux,initrd-end", initrd_end, 0); - } + if ((of_flat_tree) && (initrd_start && initrd_end)) + fdt_initrd(of_flat_tree, initrd_start, initrd_end, 1); ^^^^^^^^^^^^ At this place (see explanation before) initrd_start has the value for the initrd in RAM! -> the search for this new address in fdt_initrd () is useless, even dangerous, if the initrd is not moved, to RAM this search is succesful and for this case the right mem reservation gets deleted ... #endif
Nevertheless, the actual Code works with my patch fine, so again the question, why we need this dummy call in fdt_chosen for the initrd, when we call it later with the right values.
I think we can drop this useless dummy call from fdt_chosen. Has somebody any suggestions?
bye, Heiko