Fix code comments/documentation related to printk.
Sprinkle TODOs all over obviously wrong comments.
Document possible execution flow alternatives for later investigation.
Signed-off-by: Carl-Daniel Hailfinger <[EMAIL PROTECTED]>
---
Index: LinuxBIOSv3/mainboard/adl/msm800sev/stage1.c
===================================================================
--- LinuxBIOSv3/mainboard/adl/msm800sev/stage1.c (Revision 509)
+++ LinuxBIOSv3/mainboard/adl/msm800sev/stage1.c (Arbeitskopie)
@@ -51,5 +51,5 @@
*/
cs5536_disable_internal_uart();
w83627hf_enable_serial(0x2e, SERIAL_DEV, SERIAL_IOBASE);
- printk(BIOS_DEBUG, "Done %s\n", __FUNCTION__);
+ /* We can NOT yet use printk! */
}
Index: LinuxBIOSv3/mainboard/emulation/qemu-x86/stage1.c
===================================================================
--- LinuxBIOSv3/mainboard/emulation/qemu-x86/stage1.c (Revision 509)
+++ LinuxBIOSv3/mainboard/emulation/qemu-x86/stage1.c (Arbeitskopie)
@@ -17,7 +17,7 @@
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
-/* no printk allowed until hardware is ready; hardware is ready */
+/* no printk allowed until hardware is ready; hardware is not yet ready */
/**
* start up hardware needed for stage1
Index: LinuxBIOSv3/lib/stage2.c
===================================================================
--- LinuxBIOSv3/lib/stage2.c (Revision 509)
+++ LinuxBIOSv3/lib/stage2.c (Arbeitskopie)
@@ -37,7 +37,10 @@
*
* Device Enumeration: in the dev_enumerate() phase.
*
- * TODO: Check whether this documentation is still correct. Improve it.
+ * TODO:
+ * - Check whether this documentation is still correct. Improve it.
+ * - Replace magic constants by #defines.
+ * - Fix POST codes. Right now phases 1+3 have POST 0x30, phases 2+4 have 0x40.
*/
int stage2(void)
{
@@ -54,13 +57,19 @@
post_code(0x20);
- /* TODO: Explain why we use printk here although it is impossible */
+ /* TODO: Explain why we use printk here although it is claimed to be
+ * impossible according to the documentation. The "has to be done
+ * before printk can be used" comment below seems to suggest the same.
+ * However, we already enable serial in arch/x86/stage1.c:stage1_main()
+ * when we call hardware_stage1(); uart_init(); console_init();
+ */
printk(BIOS_NOTICE, console_test);
dev_init();
/* Console init, also ANYTHING that has to be done
- * before printk can be used.
+ * before printk can be used.
+ * FIXME: This comment contradicts the comment above.
*/
post_code(0x30);
dev_phase1();
Index: LinuxBIOSv3/arch/x86/stage1.c
===================================================================
--- LinuxBIOSv3/arch/x86/stage1.c (Revision 509)
+++ LinuxBIOSv3/arch/x86/stage1.c (Arbeitskopie)
@@ -108,8 +108,12 @@
//
uart_init(); // initialize serial port
- console_init(); // print banner
+ /* Exactly from now on we can use printk. Celebrate this by printing
+ * a LB banner.
+ */
+ console_init();
+
if (bist!=0) {
printk(BIOS_INFO, "BIST FAILED: %08x", bist);
die("");
@@ -133,6 +137,30 @@
// FIXME check integrity
+ /* Right now we have to fit
+ * initram stack
+ * lar stack
+ * into cache during CAR. IFF we can be sure that
+ * nrv2b stack
+ * initram code
+ * lar code
+ * fit into cache as well, we can compress initram code and lar code,
+ * leading to potential speedup (due to having to read less from ROM)
+ * and size savings. However, initram code and lar code would have
+ * to be compiled as PIC code, not as XIP code.
+ *
+ * Suggested code flow:
+ * unrv2b(lar_code);
+ * ...
+ * execute_in_car(&archive, "normal/initram");
+ *
+ * A less complicated (from a linker perspective) variant would
+ * compress only initram code, but it is not clear whether all hardware
+ * can run code from cache while training memory in the area designated
+ * by the cache. Some processors might drop cache contents in that case,
+ * rendering the ideas above mostly moot.
+ * TODO: Check how this works in the real world.
+ */
// find first initram
if (check_normal_boot_flag()) {
printk(BIOS_DEBUG, "Choosing normal boot.\n");
--
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