Use of both UART's
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Use of both UART's
by Prasad.Nagapati
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Hello Everyone, I am using the Borad version 1.3 H, In this I want to use both the UART's in my application, but when I saw UART application code I observed that it is using UART0 as the port, but if I connect the UART0 to the COM1 of my host PC nothing is coming (UART0 is also JTAG port in the board), but if I connect to the UART1 in the board all messages are displayed in the host PC!! How this is possible? Please help me how to use both the UART's in my application. Warm Regards Prasad _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion |
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Bootloader linker script and startup
by Hans Bacher
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Hi,
I am trying to compile a Nut/OS project to work with Atmel's layer-based bootloader: "Safe and Secure Bootloader Implementation" (application notes, AT91SAM7X). I am developing with Atmel's AT91SAM7X256-EK and I flashed the bootloader to the board. Two sample programs are provided with the bootloader itself. One example uses interrupt vector table remapping(??), the other one doesn't. The bootloader works fine with both programs. Unfortunately the bootloader and the sample applications have been developed using IAR compiler, and the fact that both only compile with IAR Workbench compiler version 4.4x is even worse... The bootloader is programmed to flash memory at start address 0x00100000 (0x00000000), thus it is executed first when powering the board. The bootloader region is 0x8000 bytes long, therefore the application flashed by the bootloader starts at address 0x00108000. Because IAR startup scripts and linker files differ quite a lot from their Nut/OS correspondences, I do not know what to change within the linker/startup script to get the Nut/OS application to run after being flashed by the botloader. I have changed the rom start address in at91sam7x256_rom.ld to 0x00008000, but apparently this doesn't suffice, because the board freezes after exiting the bootloader trying to jump to the Nut/OS application program. Can anybody tell me what changes I have to make? Do I need this interrupt vector remapping?? Thanks and regards, Hans Bacher __________ Hinweis von ESET Smart Security, Signaturdatenbank-Version 4108 (20090527) __________ E-Mail wurde gepruft mit ESET Smart Security. http://www.eset.com _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion |
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Re: Bootloader linker script and startup
by Ethernut
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Hans Bacher wrote:
> I am trying to compile a Nut/OS project to work with Atmel's layer-based > bootloader: "Safe and Secure Bootloader Implementation" (application notes, > AT91SAM7X). ... > The bootloader is programmed to flash memory at start address 0x00100000 > (0x00000000), thus it is executed first when powering the board. The > bootloader region is 0x8000 bytes long, therefore the application flashed by > the bootloader starts at address 0x00108000. Hallo Hans, Most probably the problem is with the runtime initialization (crtat91sam7x256_rom.S, actually the included crtat91sam7sex_rom.S), not the linker script (at91sam7x256_rom.ld). The system assumes, that its interrupt and exception vectors are at 0x00000000. But this location is occupied by your boot loader. I do not the anything about this boot loader, but you need to find a way to ...either get the vectors of the Nut/OS image to the beginning of the Flash ...or adapt the Nut/OS interrupts to the boot loader code somehow. While following the discussions in this list, there had been several queries and attempts to create an Ethernet boot loader for the SAM7X. AFAIK, without any result. I won't say that it is impossible, but it is for sure tricky. The boot loading on Ethernut 3 was much easier to implement, because RAM can be mapped to 0x00000000. In this environment the runtime initialization simply copies the vectors from Flash to RAM. (Well, it is not that easy, because the code has to be relocatable.) Harald _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion |
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Re: Bootloader linker script and startup
by Dave Warren
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Hi Harald & Hans,
You can make a bootloader for AT91SAM7X, I know, because I have one. As you say vecters must be copied to RAM then remapped to 0x0, use /* Copy exception vectors into Internal SRAM */ mov r8, #0x00200000 ldr r9, =_vectors ldmia r9!, {r0-r7} stmia r8!, {r0-r7} ldmia r9!, {r0-r6} stmia r8!, {r0-r6} /* Remap Internal SRAM to 0x00000000 */ ldr r1, =MC_BASE ldr r0, =1 strb r0, [r1, #MC_RCR_OFFSET] Good luck regards Dave ----- Original Message ----- From: "Harald Kipp" <harald.kipp@...> To: "Ethernut User Chat (English)" <en-nut-discussion@...> Sent: Wednesday, May 27, 2009 2:43 PM Subject: Re: [En-Nut-Discussion] Bootloader linker script and startup > Hans Bacher wrote: > >> I am trying to compile a Nut/OS project to work with Atmel's layer-based >> bootloader: "Safe and Secure Bootloader Implementation" (application >> notes, >> AT91SAM7X). > > ... > >> The bootloader is programmed to flash memory at start address 0x00100000 >> (0x00000000), thus it is executed first when powering the board. The >> bootloader region is 0x8000 bytes long, therefore the application flashed >> by >> the bootloader starts at address 0x00108000. > > Hallo Hans, > > Most probably the problem is with the runtime initialization > (crtat91sam7x256_rom.S, actually the included crtat91sam7sex_rom.S), not > the linker script (at91sam7x256_rom.ld). The system assumes, that its > interrupt and exception vectors are at 0x00000000. But this location is > occupied by your boot loader. > > I do not the anything about this boot loader, but you need to find a way > to > > ...either get the vectors of the Nut/OS image to the beginning of the > Flash > > ...or adapt the Nut/OS interrupts to the boot loader code somehow. > > While following the discussions in this list, there had been several > queries and attempts to create an Ethernet boot loader for the SAM7X. > AFAIK, without any result. I won't say that it is impossible, but it is > for sure tricky. > > The boot loading on Ethernut 3 was much easier to implement, because RAM > can be mapped to 0x00000000. In this environment the runtime > initialization simply copies the vectors from Flash to RAM. (Well, it is > not that easy, because the code has to be relocatable.) > > Harald > > > _______________________________________________ > http://lists.egnite.de/mailman/listinfo/en-nut-discussion _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion |
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Re: Bootloader linker script and startup
by Hans Bacher
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Hi Harald, hi Dave,
thank you for the hint. But doesn't remapping RAM to 0x00000000 also mean, that I have to place all my executable code (segment .text) into RAM either? This would be very restrictive to maximum application size... Thanks and regards, Hans -----Ursprüngliche Nachricht----- Von: en-nut-discussion-bounces@... [mailto:en-nut-discussion-bounces@...] Im Auftrag von Dave Warren Gesendet: Mittwoch, 27. Mai 2009 15:57 An: Ethernut User Chat (English) Betreff: Re: [En-Nut-Discussion] Bootloader linker script and startup Hi Harald & Hans, You can make a bootloader for AT91SAM7X, I know, because I have one. As you say vecters must be copied to RAM then remapped to 0x0, use /* Copy exception vectors into Internal SRAM */ mov r8, #0x00200000 ldr r9, =_vectors ldmia r9!, {r0-r7} stmia r8!, {r0-r7} ldmia r9!, {r0-r6} stmia r8!, {r0-r6} /* Remap Internal SRAM to 0x00000000 */ ldr r1, =MC_BASE ldr r0, =1 strb r0, [r1, #MC_RCR_OFFSET] Good luck regards Dave ----- Original Message ----- From: "Harald Kipp" <harald.kipp@...> To: "Ethernut User Chat (English)" <en-nut-discussion@...> Sent: Wednesday, May 27, 2009 2:43 PM Subject: Re: [En-Nut-Discussion] Bootloader linker script and startup > Hans Bacher wrote: > >> I am trying to compile a Nut/OS project to work with Atmel's layer-based >> bootloader: "Safe and Secure Bootloader Implementation" (application >> notes, >> AT91SAM7X). > > ... > >> The bootloader is programmed to flash memory at start address 0x00100000 >> (0x00000000), thus it is executed first when powering the board. The >> bootloader region is 0x8000 bytes long, therefore the application flashed >> by >> the bootloader starts at address 0x00108000. > > Hallo Hans, > > Most probably the problem is with the runtime initialization > (crtat91sam7x256_rom.S, actually the included crtat91sam7sex_rom.S), not > the linker script (at91sam7x256_rom.ld). The system assumes, that its > interrupt and exception vectors are at 0x00000000. But this location is > occupied by your boot loader. > > I do not the anything about this boot loader, but you need to find a way > to > > ...either get the vectors of the Nut/OS image to the beginning of the > Flash > > ...or adapt the Nut/OS interrupts to the boot loader code somehow. > > While following the discussions in this list, there had been several > queries and attempts to create an Ethernet boot loader for the SAM7X. > AFAIK, without any result. I won't say that it is impossible, but it is > for sure tricky. > > The boot loading on Ethernut 3 was much easier to implement, because RAM > can be mapped to 0x00000000. In this environment the runtime > initialization simply copies the vectors from Flash to RAM. (Well, it is > not that easy, because the code has to be relocatable.) > > Harald > > > _______________________________________________ > http://lists.egnite.de/mailman/listinfo/en-nut-discussion _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion |
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Re: Bootloader linker script and startup
by Dave Warren
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Hans,
Link executable to flash, only vectors have to be in RAM. regards Dave ----- Original Message ----- From: "Hans Bacher" <hans@...> To: "'Ethernut User Chat (English)'" <en-nut-discussion@...> Sent: Wednesday, May 27, 2009 4:11 PM Subject: Re: [En-Nut-Discussion] Bootloader linker script and startup Hi Harald, hi Dave, thank you for the hint. But doesn't remapping RAM to 0x00000000 also mean, that I have to place all my executable code (segment .text) into RAM either? This would be very restrictive to maximum application size... Thanks and regards, Hans -----Ursprüngliche Nachricht----- Von: en-nut-discussion-bounces@... [mailto:en-nut-discussion-bounces@...] Im Auftrag von Dave Warren Gesendet: Mittwoch, 27. Mai 2009 15:57 An: Ethernut User Chat (English) Betreff: Re: [En-Nut-Discussion] Bootloader linker script and startup Hi Harald & Hans, You can make a bootloader for AT91SAM7X, I know, because I have one. As you say vecters must be copied to RAM then remapped to 0x0, use /* Copy exception vectors into Internal SRAM */ mov r8, #0x00200000 ldr r9, =_vectors ldmia r9!, {r0-r7} stmia r8!, {r0-r7} ldmia r9!, {r0-r6} stmia r8!, {r0-r6} /* Remap Internal SRAM to 0x00000000 */ ldr r1, =MC_BASE ldr r0, =1 strb r0, [r1, #MC_RCR_OFFSET] Good luck regards Dave ----- Original Message ----- From: "Harald Kipp" <harald.kipp@...> To: "Ethernut User Chat (English)" <en-nut-discussion@...> Sent: Wednesday, May 27, 2009 2:43 PM Subject: Re: [En-Nut-Discussion] Bootloader linker script and startup > Hans Bacher wrote: > >> I am trying to compile a Nut/OS project to work with Atmel's layer-based >> bootloader: "Safe and Secure Bootloader Implementation" (application >> notes, >> AT91SAM7X). > > ... > >> The bootloader is programmed to flash memory at start address 0x00100000 >> (0x00000000), thus it is executed first when powering the board. The >> bootloader region is 0x8000 bytes long, therefore the application flashed >> by >> the bootloader starts at address 0x00108000. > > Hallo Hans, > > Most probably the problem is with the runtime initialization > (crtat91sam7x256_rom.S, actually the included crtat91sam7sex_rom.S), not > the linker script (at91sam7x256_rom.ld). The system assumes, that its > interrupt and exception vectors are at 0x00000000. But this location is > occupied by your boot loader. > > I do not the anything about this boot loader, but you need to find a way > to > > ...either get the vectors of the Nut/OS image to the beginning of the > Flash > > ...or adapt the Nut/OS interrupts to the boot loader code somehow. > > While following the discussions in this list, there had been several > queries and attempts to create an Ethernet boot loader for the SAM7X. > AFAIK, without any result. I won't say that it is impossible, but it is > for sure tricky. > > The boot loading on Ethernut 3 was much easier to implement, because RAM > can be mapped to 0x00000000. In this environment the runtime > initialization simply copies the vectors from Flash to RAM. (Well, it is > not that easy, because the code has to be relocatable.) > > Harald > > > _______________________________________________ > http://lists.egnite.de/mailman/listinfo/en-nut-discussion _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion |
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Re: Bootloader linker script and startup
by Ethernut
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Dave Warren wrote:
> Hi Harald & Hans, > > You can make a bootloader for AT91SAM7X, I know, because I have one. As you > say vecters must be copied to RAM then remapped to 0x0, use You're right. I overlooked that internal RAM of the SAM devices can be mapped to address zero in any case. Sorry for the confusion. Harald _______________________________________________ http://lists.egnite.de/mailman/listinfo/en-nut-discussion |
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